bond_main.c

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/*
 * originally based on the dummy device.
 *
 * Copyright 1999, Thomas Davis, [email protected].
 * Licensed under the GPL. Based on dummy.c, and eql.c devices.
 *
 * bonding.c: an Ethernet Bonding driver
 *
 * This is useful to talk to a Cisco EtherChannel compatible equipment:
 *  Cisco 5500
 *  Sun Trunking (Solaris)
 *  Alteon AceDirector Trunks
 *  Linux Bonding
 *  and probably many L2 switches ...
 *
 * How it works:
 *    ifconfig bond0 ipaddress netmask up
 *      will setup a network device, with an ip address.  No mac address
 *  will be assigned at this time.  The hw mac address will come from
 *  the first slave bonded to the channel.  All slaves will then use
 *  this hw mac address.
 *
 *    ifconfig bond0 down
 *         will release all slaves, marking them as down.
 *
 *    ifenslave bond0 eth0
 *  will attach eth0 to bond0 as a slave.  eth0 hw mac address will either
 *  a: be used as initial mac address
 *  b: if a hw mac address already is there, eth0's hw mac address
 *     will then be set from bond0.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <net/ip.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/socket.h>
#include <linux/ctype.h>
#include <linux/inet.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <asm/dma.h>
#include <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/rtnetlink.h>
#include <linux/smp.h>
#include <linux/if_ether.h>
#include <net/arp.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include <linux/if_bonding.h>
#include <linux/jiffies.h>
#include <linux/preempt.h>
#include <net/route.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/pkt_sched.h>
#include "bonding.h"
#include "bond_3ad.h"
#include "bond_alb.h"

/*---------------------------- Module parameters ----------------------------*/

/* monitor all links that often (in milliseconds). <=0 disables monitoring */
#define BOND_LINK_MON_INTERV    0
#define BOND_LINK_ARP_INTERV    0

static int max_bonds    = BOND_DEFAULT_MAX_BONDS;
static int tx_queues    = BOND_DEFAULT_TX_QUEUES;
static int num_peer_notif = 1;
static int miimon   = BOND_LINK_MON_INTERV;
static int updelay;
static int downdelay;
static int use_carrier  = 1;
static char *mode;
static char *primary;
static char *primary_reselect;
static char *lacp_rate;
static int min_links;
static char *ad_select;
static char *xmit_hash_policy;
static int arp_interval = BOND_LINK_ARP_INTERV;
static char *arp_ip_target[BOND_MAX_ARP_TARGETS];
static char *arp_validate;
static char *fail_over_mac;
static int all_slaves_active = 0;
static struct bond_params bonding_defaults;
static int resend_igmp = BOND_DEFAULT_RESEND_IGMP;

module_param(max_bonds, int, 0);
MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
module_param(tx_queues, int, 0);
MODULE_PARM_DESC(tx_queues, "Max number of transmit queues (default = 16)");
module_param_named(num_grat_arp, num_peer_notif, int, 0644);
MODULE_PARM_DESC(num_grat_arp, "Number of peer notifications to send on "
                   "failover event (alias of num_unsol_na)");
module_param_named(num_unsol_na, num_peer_notif, int, 0644);
MODULE_PARM_DESC(num_unsol_na, "Number of peer notifications to send on "
                   "failover event (alias of num_grat_arp)");
module_param(miimon, int, 0);
MODULE_PARM_DESC(miimon, "Link check interval in milliseconds");
module_param(updelay, int, 0);
MODULE_PARM_DESC(updelay, "Delay before considering link up, in milliseconds");
module_param(downdelay, int, 0);
MODULE_PARM_DESC(downdelay, "Delay before considering link down, "
                "in milliseconds");
module_param(use_carrier, int, 0);
MODULE_PARM_DESC(use_carrier, "Use netif_carrier_ok (vs MII ioctls) in miimon; "
                  "0 for off, 1 for on (default)");
module_param(mode, charp, 0);
MODULE_PARM_DESC(mode, "Mode of operation; 0 for balance-rr, "
               "1 for active-backup, 2 for balance-xor, "
               "3 for broadcast, 4 for 802.3ad, 5 for balance-tlb, "
               "6 for balance-alb");
module_param(primary, charp, 0);
MODULE_PARM_DESC(primary, "Primary network device to use");
module_param(primary_reselect, charp, 0);
MODULE_PARM_DESC(primary_reselect, "Reselect primary slave "
                   "once it comes up; "
                   "0 for always (default), "
                   "1 for only if speed of primary is "
                   "better, "
                   "2 for only on active slave "
                   "failure");
module_param(lacp_rate, charp, 0);
MODULE_PARM_DESC(lacp_rate, "LACPDU tx rate to request from 802.3ad partner; "
                "0 for slow, 1 for fast");
module_param(ad_select, charp, 0);
MODULE_PARM_DESC(ad_select, "803.ad aggregation selection logic; "
                "0 for stable (default), 1 for bandwidth, "
                "2 for count");
module_param(min_links, int, 0);
MODULE_PARM_DESC(min_links, "Minimum number of available links before turning on carrier");

module_param(xmit_hash_policy, charp, 0);
MODULE_PARM_DESC(xmit_hash_policy, "balance-xor and 802.3ad hashing method; "
                   "0 for layer 2 (default), 1 for layer 3+4, "
                   "2 for layer 2+3");
module_param(arp_interval, int, 0);
MODULE_PARM_DESC(arp_interval, "arp interval in milliseconds");
module_param_array(arp_ip_target, charp, NULL, 0);
MODULE_PARM_DESC(arp_ip_target, "arp targets in n.n.n.n form");
module_param(arp_validate, charp, 0);
MODULE_PARM_DESC(arp_validate, "validate src/dst of ARP probes; "
                   "0 for none (default), 1 for active, "
                   "2 for backup, 3 for all");
module_param(fail_over_mac, charp, 0);
MODULE_PARM_DESC(fail_over_mac, "For active-backup, do not set all slaves to "
                "the same MAC; 0 for none (default), "
                "1 for active, 2 for follow");
module_param(all_slaves_active, int, 0);
MODULE_PARM_DESC(all_slaves_active, "Keep all frames received on an interface"
                     "by setting active flag for all slaves; "
                     "0 for never (default), 1 for always.");
module_param(resend_igmp, int, 0);
MODULE_PARM_DESC(resend_igmp, "Number of IGMP membership reports to send on "
                  "link failure");

/*----------------------------- Global variables ----------------------------*/

#ifdef CONFIG_NET_POLL_CONTROLLER
atomic_t netpoll_block_tx = ATOMIC_INIT(0);
#endif

int bond_net_id __read_mostly;

static __be32 arp_target[BOND_MAX_ARP_TARGETS];
static int arp_ip_count;
static int bond_mode    = BOND_MODE_ROUNDROBIN;
static int xmit_hashtype = BOND_XMIT_POLICY_LAYER2;
static int lacp_fast;

const struct bond_parm_tbl bond_lacp_tbl[] = {
{   "slow",     AD_LACP_SLOW},
{   "fast",     AD_LACP_FAST},
{   NULL,       -1},
};

const struct bond_parm_tbl bond_mode_tbl[] = {
{   "balance-rr",       BOND_MODE_ROUNDROBIN},
{   "active-backup",    BOND_MODE_ACTIVEBACKUP},
{   "balance-xor",      BOND_MODE_XOR},
{   "broadcast",        BOND_MODE_BROADCAST},
{   "802.3ad",      BOND_MODE_8023AD},
{   "balance-tlb",      BOND_MODE_TLB},
{   "balance-alb",      BOND_MODE_ALB},
{   NULL,           -1},
};

const struct bond_parm_tbl xmit_hashtype_tbl[] = {
{   "layer2",       BOND_XMIT_POLICY_LAYER2},
{   "layer3+4",     BOND_XMIT_POLICY_LAYER34},
{   "layer2+3",     BOND_XMIT_POLICY_LAYER23},
{   NULL,           -1},
};

const struct bond_parm_tbl arp_validate_tbl[] = {
{   "none",         BOND_ARP_VALIDATE_NONE},
{   "active",       BOND_ARP_VALIDATE_ACTIVE},
{   "backup",       BOND_ARP_VALIDATE_BACKUP},
{   "all",          BOND_ARP_VALIDATE_ALL},
{   NULL,           -1},
};

const struct bond_parm_tbl fail_over_mac_tbl[] = {
{   "none",         BOND_FOM_NONE},
{   "active",       BOND_FOM_ACTIVE},
{   "follow",       BOND_FOM_FOLLOW},
{   NULL,           -1},
};

const struct bond_parm_tbl pri_reselect_tbl[] = {
{   "always",       BOND_PRI_RESELECT_ALWAYS},
{   "better",       BOND_PRI_RESELECT_BETTER},
{   "failure",      BOND_PRI_RESELECT_FAILURE},
{   NULL,           -1},
};

struct bond_parm_tbl ad_select_tbl[] = {
{   "stable",   BOND_AD_STABLE},
{   "bandwidth",    BOND_AD_BANDWIDTH},
{   "count",    BOND_AD_COUNT},
{   NULL,       -1},
};

/*-------------------------- Forward declarations ---------------------------*/

static int bond_init(struct net_device *bond_dev);
static void bond_uninit(struct net_device *bond_dev);

/*---------------------------- General routines -----------------------------*/

const char *bond_mode_name(int mode)
{
    static const char *names[] = {
        [BOND_MODE_ROUNDROBIN] = "load balancing (round-robin)",
        [BOND_MODE_ACTIVEBACKUP] = "fault-tolerance (active-backup)",
        [BOND_MODE_XOR] = "load balancing (xor)",
        [BOND_MODE_BROADCAST] = "fault-tolerance (broadcast)",
        [BOND_MODE_8023AD] = "IEEE 802.3ad Dynamic link aggregation",
        [BOND_MODE_TLB] = "transmit load balancing",
        [BOND_MODE_ALB] = "adaptive load balancing",
    };

    if (mode < 0 || mode > BOND_MODE_ALB)
        return "unknown";

    return names[mode];
}

/*---------------------------------- VLAN -----------------------------------*/

static int bond_add_vlan(struct bonding *bond, unsigned short vlan_id)
{
    struct vlan_entry *vlan;

    pr_debug("bond: %s, vlan id %d\n",
         (bond ? bond->dev->name : "None"), vlan_id);

    vlan = kzalloc(sizeof(struct vlan_entry), GFP_KERNEL);
    if (!vlan)
        return -ENOMEM;

    INIT_LIST_HEAD(&vlan->vlan_list);
    vlan->vlan_id = vlan_id;

    write_lock_bh(&bond->lock);

    list_add_tail(&vlan->vlan_list, &bond->vlan_list);

    write_unlock_bh(&bond->lock);

    pr_debug("added VLAN ID %d on bond %s\n", vlan_id, bond->dev->name);

    return 0;
}

static int bond_del_vlan(struct bonding *bond, unsigned short vlan_id)
{
    struct vlan_entry *vlan;
    int res = -ENODEV;

    pr_debug("bond: %s, vlan id %d\n", bond->dev->name, vlan_id);

    block_netpoll_tx();
    write_lock_bh(&bond->lock);

    list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
        if (vlan->vlan_id == vlan_id) {
            list_del(&vlan->vlan_list);

            if (bond_is_lb(bond))
                bond_alb_clear_vlan(bond, vlan_id);

            pr_debug("removed VLAN ID %d from bond %s\n",
                 vlan_id, bond->dev->name);

            kfree(vlan);

            res = 0;
            goto out;
        }
    }

    pr_debug("couldn't find VLAN ID %d in bond %s\n",
         vlan_id, bond->dev->name);

out:
    write_unlock_bh(&bond->lock);
    unblock_netpoll_tx();
    return res;
}

struct vlan_entry *bond_next_vlan(struct bonding *bond, struct vlan_entry *curr)
{
    struct vlan_entry *next, *last;

    if (list_empty(&bond->vlan_list))
        return NULL;

    if (!curr) {
        next = list_entry(bond->vlan_list.next,
                  struct vlan_entry, vlan_list);
    } else {
        last = list_entry(bond->vlan_list.prev,
                  struct vlan_entry, vlan_list);
        if (last == curr) {
            next = list_entry(bond->vlan_list.next,
                      struct vlan_entry, vlan_list);
        } else {
            next = list_entry(curr->vlan_list.next,
                      struct vlan_entry, vlan_list);
        }
    }

    return next;
}

int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb,
            struct net_device *slave_dev)
{
    skb->dev = slave_dev;

    BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
             sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
    skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;

    if (unlikely(netpoll_tx_running(bond->dev)))
        bond_netpoll_send_skb(bond_get_slave_by_dev(bond, slave_dev), skb);
    else
        dev_queue_xmit(skb);

    return 0;
}

/*
 * In the following 2 functions, bond_vlan_rx_add_vid and bond_vlan_rx_kill_vid,
 * We don't protect the slave list iteration with a lock because:
 * a. This operation is performed in IOCTL context,
 * b. The operation is protected by the RTNL semaphore in the 8021q code,
 * c. Holding a lock with BH disabled while directly calling a base driver
 *    entry point is generally a BAD idea.
 *
 * The design of synchronization/protection for this operation in the 8021q
 * module is good for one or more VLAN devices over a single physical device
 * and cannot be extended for a teaming solution like bonding, so there is a
 * potential race condition here where a net device from the vlan group might
 * be referenced (either by a base driver or the 8021q code) while it is being
 * removed from the system. However, it turns out we're not making matters
 * worse, and if it works for regular VLAN usage it will work here too.
*/

static int bond_vlan_rx_add_vid(struct net_device *bond_dev, uint16_t vid)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave, *stop_at;
    int i, res;

    bond_for_each_slave(bond, slave, i) {
        res = vlan_vid_add(slave->dev, vid);
        if (res)
            goto unwind;
    }

    res = bond_add_vlan(bond, vid);
    if (res) {
        pr_err("%s: Error: Failed to add vlan id %d\n",
               bond_dev->name, vid);
        return res;
    }

    return 0;

unwind:
    /* 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)
        vlan_vid_del(slave->dev, vid);

    return res;
}

static int bond_vlan_rx_kill_vid(struct net_device *bond_dev, uint16_t vid)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave;
    int i, res;

    bond_for_each_slave(bond, slave, i)
        vlan_vid_del(slave->dev, vid);

    res = bond_del_vlan(bond, vid);
    if (res) {
        pr_err("%s: Error: Failed to remove vlan id %d\n",
               bond_dev->name, vid);
        return res;
    }

    return 0;
}

static void bond_add_vlans_on_slave(struct bonding *bond, struct net_device *slave_dev)
{
    struct vlan_entry *vlan;
    int res;

    list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
        res = vlan_vid_add(slave_dev, vlan->vlan_id);
        if (res)
            pr_warning("%s: Failed to add vlan id %d to device %s\n",
                   bond->dev->name, vlan->vlan_id,
                   slave_dev->name);
    }
}

static void bond_del_vlans_from_slave(struct bonding *bond,
                      struct net_device *slave_dev)
{
    struct vlan_entry *vlan;

    list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
        if (!vlan->vlan_id)
            continue;
        vlan_vid_del(slave_dev, vlan->vlan_id);
    }
}

/*------------------------------- Link status -------------------------------*/

/*
 * Set the carrier state for the master according to the state of its
 * slaves.  If any slaves are up, the master is up.  In 802.3ad mode,
 * do special 802.3ad magic.
 *
 * Returns zero if carrier state does not change, nonzero if it does.
 */
static int bond_set_carrier(struct bonding *bond)
{
    struct slave *slave;
    int i;

    if (bond->slave_cnt == 0)
        goto down;

    if (bond->params.mode == BOND_MODE_8023AD)
        return bond_3ad_set_carrier(bond);

    bond_for_each_slave(bond, slave, i) {
        if (slave->link == BOND_LINK_UP) {
            if (!netif_carrier_ok(bond->dev)) {
                netif_carrier_on(bond->dev);
                return 1;
            }
            return 0;
        }
    }

down:
    if (netif_carrier_ok(bond->dev)) {
        netif_carrier_off(bond->dev);
        return 1;
    }
    return 0;
}

/*
 * Get link speed and duplex from the slave's base driver
 * using ethtool. If for some reason the call fails or the
 * values are invalid, set speed and duplex to -1,
 * and return.
 */
static void bond_update_speed_duplex(struct slave *slave)
{
    struct net_device *slave_dev = slave->dev;
    struct ethtool_cmd ecmd;
    u32 slave_speed;
    int res;

    slave->speed = SPEED_UNKNOWN;
    slave->duplex = DUPLEX_UNKNOWN;

    res = __ethtool_get_settings(slave_dev, &ecmd);
    if (res < 0)
        return;

    slave_speed = ethtool_cmd_speed(&ecmd);
    if (slave_speed == 0 || slave_speed == ((__u32) -1))
        return;

    switch (ecmd.duplex) {
    case DUPLEX_FULL:
    case DUPLEX_HALF:
        break;
    default:
        return;
    }

    slave->speed = slave_speed;
    slave->duplex = ecmd.duplex;

    return;
}

/*
 * if <dev> supports MII link status reporting, check its link status.
 *
 * We either do MII/ETHTOOL ioctls, or check netif_carrier_ok(),
 * depending upon the setting of the use_carrier parameter.
 *
 * Return either BMSR_LSTATUS, meaning that the link is up (or we
 * can't tell and just pretend it is), or 0, meaning that the link is
 * down.
 *
 * If reporting is non-zero, instead of faking link up, return -1 if
 * both ETHTOOL and MII ioctls fail (meaning the device does not
 * support them).  If use_carrier is set, return whatever it says.
 * It'd be nice if there was a good way to tell if a driver supports
 * netif_carrier, but there really isn't.
 */
static int bond_check_dev_link(struct bonding *bond,
                   struct net_device *slave_dev, int reporting)
{
    const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
    int (*ioctl)(struct net_device *, struct ifreq *, int);
    struct ifreq ifr;
    struct mii_ioctl_data *mii;

    if (!reporting && !netif_running(slave_dev))
        return 0;

    if (bond->params.use_carrier)
        return netif_carrier_ok(slave_dev) ? BMSR_LSTATUS : 0;

    /* Try to get link status using Ethtool first. */
    if (slave_dev->ethtool_ops) {
        if (slave_dev->ethtool_ops->get_link) {
            u32 link;

            link = slave_dev->ethtool_ops->get_link(slave_dev);

            return link ? BMSR_LSTATUS : 0;
        }
    }

    /* Ethtool can't be used, fallback to MII ioctls. */
    ioctl = slave_ops->ndo_do_ioctl;
    if (ioctl) {
        /* TODO: set pointer to correct ioctl on a per team member */
        /*       bases to make this more efficient. that is, once  */
        /*       we determine the correct ioctl, we will always    */
        /*       call it and not the others for that team          */
        /*       member.                                           */

        /*
         * We cannot assume that SIOCGMIIPHY will also read a
         * register; not all network drivers (e.g., e100)
         * support that.
         */

        /* Yes, the mii is overlaid on the ifreq.ifr_ifru */
        strncpy(ifr.ifr_name, slave_dev->name, IFNAMSIZ);
        mii = if_mii(&ifr);
        if (IOCTL(slave_dev, &ifr, SIOCGMIIPHY) == 0) {
            mii->reg_num = MII_BMSR;
            if (IOCTL(slave_dev, &ifr, SIOCGMIIREG) == 0)
                return mii->val_out & BMSR_LSTATUS;
        }
    }

    /*
     * If reporting, report that either there's no dev->do_ioctl,
     * or both SIOCGMIIREG and get_link failed (meaning that we
     * cannot report link status).  If not reporting, pretend
     * we're ok.
     */
    return reporting ? -1 : BMSR_LSTATUS;
}

/*----------------------------- Multicast list ------------------------------*/

/*
 * Push the promiscuity flag down to appropriate slaves
 */
static int bond_set_promiscuity(struct bonding *bond, int inc)
{
    int err = 0;
    if (USES_PRIMARY(bond->params.mode)) {
        /* write lock already acquired */
        if (bond->curr_active_slave) {
            err = dev_set_promiscuity(bond->curr_active_slave->dev,
                          inc);
        }
    } else {
        struct slave *slave;
        int i;
        bond_for_each_slave(bond, slave, i) {
            err = dev_set_promiscuity(slave->dev, inc);
            if (err)
                return err;
        }
    }
    return err;
}

/*
 * Push the allmulti flag down to all slaves
 */
static int bond_set_allmulti(struct bonding *bond, int inc)
{
    int err = 0;
    if (USES_PRIMARY(bond->params.mode)) {
        /* write lock already acquired */
        if (bond->curr_active_slave) {
            err = dev_set_allmulti(bond->curr_active_slave->dev,
                           inc);
        }
    } else {
        struct slave *slave;
        int i;
        bond_for_each_slave(bond, slave, i) {
            err = dev_set_allmulti(slave->dev, inc);
            if (err)
                return err;
        }
    }
    return err;
}

/*
 * Add a Multicast address to slaves
 * according to mode
 */
static void bond_mc_add(struct bonding *bond, void *addr)
{
    if (USES_PRIMARY(bond->params.mode)) {
        /* write lock already acquired */
        if (bond->curr_active_slave)
            dev_mc_add(bond->curr_active_slave->dev, addr);
    } else {
        struct slave *slave;
        int i;

        bond_for_each_slave(bond, slave, i)
            dev_mc_add(slave->dev, addr);
    }
}

/*
 * Remove a multicast address from slave
 * according to mode
 */
static void bond_mc_del(struct bonding *bond, void *addr)
{
    if (USES_PRIMARY(bond->params.mode)) {
        /* write lock already acquired */
        if (bond->curr_active_slave)
            dev_mc_del(bond->curr_active_slave->dev, addr);
    } else {
        struct slave *slave;
        int i;
        bond_for_each_slave(bond, slave, i) {
            dev_mc_del(slave->dev, addr);
        }
    }
}


static void __bond_resend_igmp_join_requests(struct net_device *dev)
{
    struct in_device *in_dev;

    rcu_read_lock();
    in_dev = __in_dev_get_rcu(dev);
    if (in_dev)
        ip_mc_rejoin_groups(in_dev);
    rcu_read_unlock();
}

/*
 * Retrieve the list of registered multicast addresses for the bonding
 * device and retransmit an IGMP JOIN request to the current active
 * slave.
 */
static void bond_resend_igmp_join_requests(struct bonding *bond)
{
    struct net_device *bond_dev, *vlan_dev, *master_dev;
    struct vlan_entry *vlan;

    read_lock(&bond->lock);

    bond_dev = bond->dev;

    /* rejoin all groups on bond device */
    __bond_resend_igmp_join_requests(bond_dev);

    /*
     * if bond is enslaved to a bridge,
     * then rejoin all groups on its master
     */
    master_dev = bond_dev->master;
    if (master_dev)
        if ((master_dev->priv_flags & IFF_EBRIDGE)
            && (bond_dev->priv_flags & IFF_BRIDGE_PORT))
            __bond_resend_igmp_join_requests(master_dev);

    /* rejoin all groups on vlan devices */
    list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
        rcu_read_lock();
        vlan_dev = __vlan_find_dev_deep(bond_dev,
                        vlan->vlan_id);
        rcu_read_unlock();
        if (vlan_dev)
            __bond_resend_igmp_join_requests(vlan_dev);
    }

    if (--bond->igmp_retrans > 0)
        queue_delayed_work(bond->wq, &bond->mcast_work, HZ/5);

    read_unlock(&bond->lock);
}

static void bond_resend_igmp_join_requests_delayed(struct work_struct *work)
{
    struct bonding *bond = container_of(work, struct bonding,
                        mcast_work.work);
    bond_resend_igmp_join_requests(bond);
}

/*
 * flush all members of flush->mc_list from device dev->mc_list
 */
static void bond_mc_list_flush(struct net_device *bond_dev,
                   struct net_device *slave_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct netdev_hw_addr *ha;

    netdev_for_each_mc_addr(ha, bond_dev)
        dev_mc_del(slave_dev, ha->addr);

    if (bond->params.mode == BOND_MODE_8023AD) {
        /* del lacpdu mc addr from mc list */
        u8 lacpdu_multicast[ETH_ALEN] = MULTICAST_LACPDU_ADDR;

        dev_mc_del(slave_dev, lacpdu_multicast);
    }
}

/*--------------------------- Active slave change ---------------------------*/

/*
 * Update the mc list and multicast-related flags for the new and
 * old active slaves (if any) according to the multicast mode, and
 * promiscuous flags unconditionally.
 */
static void bond_mc_swap(struct bonding *bond, struct slave *new_active,
             struct slave *old_active)
{
    struct netdev_hw_addr *ha;

    if (!USES_PRIMARY(bond->params.mode))
        /* nothing to do -  mc list is already up-to-date on
         * all slaves
         */
        return;

    if (old_active) {
        if (bond->dev->flags & IFF_PROMISC)
            dev_set_promiscuity(old_active->dev, -1);

        if (bond->dev->flags & IFF_ALLMULTI)
            dev_set_allmulti(old_active->dev, -1);

        netdev_for_each_mc_addr(ha, bond->dev)
            dev_mc_del(old_active->dev, ha->addr);
    }

    if (new_active) {
        /* FIXME: Signal errors upstream. */
        if (bond->dev->flags & IFF_PROMISC)
            dev_set_promiscuity(new_active->dev, 1);

        if (bond->dev->flags & IFF_ALLMULTI)
            dev_set_allmulti(new_active->dev, 1);

        netdev_for_each_mc_addr(ha, bond->dev)
            dev_mc_add(new_active->dev, ha->addr);
    }
}

/*
 * bond_do_fail_over_mac
 *
 * Perform special MAC address swapping for fail_over_mac settings
 *
 * Called with RTNL, bond->lock for read, curr_slave_lock for write_bh.
 */
static void bond_do_fail_over_mac(struct bonding *bond,
                  struct slave *new_active,
                  struct slave *old_active)
    __releases(&bond->curr_slave_lock)
    __releases(&bond->lock)
    __acquires(&bond->lock)
    __acquires(&bond->curr_slave_lock)
{
    u8 tmp_mac[ETH_ALEN];
    struct sockaddr saddr;
    int rv;

    switch (bond->params.fail_over_mac) {
    case BOND_FOM_ACTIVE:
        if (new_active) {
            memcpy(bond->dev->dev_addr,  new_active->dev->dev_addr,
                   new_active->dev->addr_len);
            write_unlock_bh(&bond->curr_slave_lock);
            read_unlock(&bond->lock);
            call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
            read_lock(&bond->lock);
            write_lock_bh(&bond->curr_slave_lock);
        }
        break;
    case BOND_FOM_FOLLOW:
        /*
         * if new_active && old_active, swap them
         * if just old_active, do nothing (going to no active slave)
         * if just new_active, set new_active to bond's MAC
         */
        if (!new_active)
            return;

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

        if (old_active) {
            memcpy(tmp_mac, new_active->dev->dev_addr, ETH_ALEN);
            memcpy(saddr.sa_data, old_active->dev->dev_addr,
                   ETH_ALEN);
            saddr.sa_family = new_active->dev->type;
        } else {
            memcpy(saddr.sa_data, bond->dev->dev_addr, ETH_ALEN);
            saddr.sa_family = bond->dev->type;
        }

        rv = dev_set_mac_address(new_active->dev, &saddr);
        if (rv) {
            pr_err("%s: Error %d setting MAC of slave %s\n",
                   bond->dev->name, -rv, new_active->dev->name);
            goto out;
        }

        if (!old_active)
            goto out;

        memcpy(saddr.sa_data, tmp_mac, ETH_ALEN);
        saddr.sa_family = old_active->dev->type;

        rv = dev_set_mac_address(old_active->dev, &saddr);
        if (rv)
            pr_err("%s: Error %d setting MAC of slave %s\n",
                   bond->dev->name, -rv, new_active->dev->name);
out:
        read_lock(&bond->lock);
        write_lock_bh(&bond->curr_slave_lock);
        break;
    default:
        pr_err("%s: bond_do_fail_over_mac impossible: bad policy %d\n",
               bond->dev->name, bond->params.fail_over_mac);
        break;
    }

}

static bool bond_should_change_active(struct bonding *bond)
{
    struct slave *prim = bond->primary_slave;
    struct slave *curr = bond->curr_active_slave;

    if (!prim || !curr || curr->link != BOND_LINK_UP)
        return true;
    if (bond->force_primary) {
        bond->force_primary = false;
        return true;
    }
    if (bond->params.primary_reselect == BOND_PRI_RESELECT_BETTER &&
        (prim->speed < curr->speed ||
         (prim->speed == curr->speed && prim->duplex <= curr->duplex)))
        return false;
    if (bond->params.primary_reselect == BOND_PRI_RESELECT_FAILURE)
        return false;
    return true;
}

static struct slave *bond_find_best_slave(struct bonding *bond)
{
    struct slave *new_active, *old_active;
    struct slave *bestslave = NULL;
    int mintime = bond->params.updelay;
    int i;

    new_active = bond->curr_active_slave;

    if (!new_active) { /* there were no active slaves left */
        if (bond->slave_cnt > 0)   /* found one slave */
            new_active = bond->first_slave;
        else
            return NULL; /* still no slave, return NULL */
    }

    if ((bond->primary_slave) &&
        bond->primary_slave->link == BOND_LINK_UP &&
        bond_should_change_active(bond)) {
        new_active = bond->primary_slave;
    }

    /* remember where to stop iterating over the slaves */
    old_active = new_active;

    bond_for_each_slave_from(bond, new_active, i, old_active) {
        if (new_active->link == BOND_LINK_UP) {
            return new_active;
        } else if (new_active->link == BOND_LINK_BACK &&
               IS_UP(new_active->dev)) {
            /* link up, but waiting for stabilization */
            if (new_active->delay < mintime) {
                mintime = new_active->delay;
                bestslave = new_active;
            }
        }
    }

    return bestslave;
}

static bool bond_should_notify_peers(struct bonding *bond)
{
    struct slave *slave = bond->curr_active_slave;

    pr_debug("bond_should_notify_peers: bond %s slave %s\n",
         bond->dev->name, slave ? slave->dev->name : "NULL");

    if (!slave || !bond->send_peer_notif ||
        test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
        return false;

    bond->send_peer_notif--;
    return true;
}

void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
{
    struct slave *old_active = bond->curr_active_slave;

    if (old_active == new_active)
        return;

    if (new_active) {
        new_active->jiffies = jiffies;

        if (new_active->link == BOND_LINK_BACK) {
            if (USES_PRIMARY(bond->params.mode)) {
                pr_info("%s: making interface %s the new active one %d ms earlier.\n",
                    bond->dev->name, new_active->dev->name,
                    (bond->params.updelay - new_active->delay) * bond->params.miimon);
            }

            new_active->delay = 0;
            new_active->link = BOND_LINK_UP;

            if (bond->params.mode == BOND_MODE_8023AD)
                bond_3ad_handle_link_change(new_active, BOND_LINK_UP);

            if (bond_is_lb(bond))
                bond_alb_handle_link_change(bond, new_active, BOND_LINK_UP);
        } else {
            if (USES_PRIMARY(bond->params.mode)) {
                pr_info("%s: making interface %s the new active one.\n",
                    bond->dev->name, new_active->dev->name);
            }
        }
    }

    if (USES_PRIMARY(bond->params.mode))
        bond_mc_swap(bond, new_active, old_active);

    if (bond_is_lb(bond)) {
        bond_alb_handle_active_change(bond, new_active);
        if (old_active)
            bond_set_slave_inactive_flags(old_active);
        if (new_active)
            bond_set_slave_active_flags(new_active);
    } else {
        bond->curr_active_slave = new_active;
    }

    if (bond->params.mode == BOND_MODE_ACTIVEBACKUP) {
        if (old_active)
            bond_set_slave_inactive_flags(old_active);

        if (new_active) {
            bool should_notify_peers = false;

            bond_set_slave_active_flags(new_active);

            if (bond->params.fail_over_mac)
                bond_do_fail_over_mac(bond, new_active,
                              old_active);

            if (netif_running(bond->dev)) {
                bond->send_peer_notif =
                    bond->params.num_peer_notif;
                should_notify_peers =
                    bond_should_notify_peers(bond);
            }

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

            call_netdevice_notifiers(NETDEV_BONDING_FAILOVER, bond->dev);
            if (should_notify_peers)
                call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
                             bond->dev);

            read_lock(&bond->lock);
            write_lock_bh(&bond->curr_slave_lock);
        }
    }

    /* resend IGMP joins since active slave has changed or
     * all were sent on curr_active_slave.
     * resend only if bond is brought up with the affected
     * bonding modes and the retransmission is enabled */
    if (netif_running(bond->dev) && (bond->params.resend_igmp > 0) &&
        ((USES_PRIMARY(bond->params.mode) && new_active) ||
         bond->params.mode == BOND_MODE_ROUNDROBIN)) {
        bond->igmp_retrans = bond->params.resend_igmp;
        queue_delayed_work(bond->wq, &bond->mcast_work, 0);
    }
}

void bond_select_active_slave(struct bonding *bond)
{
    struct slave *best_slave;
    int rv;

    best_slave = bond_find_best_slave(bond);
    if (best_slave != bond->curr_active_slave) {
        bond_change_active_slave(bond, best_slave);
        rv = bond_set_carrier(bond);
        if (!rv)
            return;

        if (netif_carrier_ok(bond->dev)) {
            pr_info("%s: first active interface up!\n",
                bond->dev->name);
        } else {
            pr_info("%s: now running without any active interface !\n",
                bond->dev->name);
        }
    }
}

/*--------------------------- slave list handling ---------------------------*/

/*
 * This function attaches the slave to the end of list.
 *
 * bond->lock held for writing by caller.
 */
static void bond_attach_slave(struct bonding *bond, struct slave *new_slave)
{
    if (bond->first_slave == NULL) { /* attaching the first slave */
        new_slave->next = new_slave;
        new_slave->prev = new_slave;
        bond->first_slave = new_slave;
    } else {
        new_slave->next = bond->first_slave;
        new_slave->prev = bond->first_slave->prev;
        new_slave->next->prev = new_slave;
        new_slave->prev->next = new_slave;
    }

    bond->slave_cnt++;
}

/*
 * This function detaches the slave from the list.
 * WARNING: no check is made to verify if the slave effectively
 * belongs to <bond>.
 * Nothing is freed on return, structures are just unchained.
 * If any slave pointer in bond was pointing to <slave>,
 * it should be changed by the calling function.
 *
 * bond->lock held for writing by caller.
 */
static void bond_detach_slave(struct bonding *bond, struct slave *slave)
{
    if (slave->next)
        slave->next->prev = slave->prev;

    if (slave->prev)
        slave->prev->next = slave->next;

    if (bond->first_slave == slave) { /* slave is the first slave */
        if (bond->slave_cnt > 1) { /* there are more slave */
            bond->first_slave = slave->next;
        } else {
            bond->first_slave = NULL; /* slave was the last one */
        }
    }

    slave->next = NULL;
    slave->prev = NULL;
    bond->slave_cnt--;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static inline int slave_enable_netpoll(struct slave *slave)
{
    struct netpoll *np;
    int err = 0;

    np = kzalloc(sizeof(*np), GFP_ATOMIC);
    err = -ENOMEM;
    if (!np)
        goto out;

    err = __netpoll_setup(np, slave->dev, GFP_ATOMIC);
    if (err) {
        kfree(np);
        goto out;
    }
    slave->np = np;
out:
    return err;
}
static inline void slave_disable_netpoll(struct slave *slave)
{
    struct netpoll *np = slave->np;

    if (!np)
        return;

    slave->np = NULL;
    __netpoll_free_rcu(np);
}
static inline bool slave_dev_support_netpoll(struct net_device *slave_dev)
{
    if (slave_dev->priv_flags & IFF_DISABLE_NETPOLL)
        return false;
    if (!slave_dev->netdev_ops->ndo_poll_controller)
        return false;
    return true;
}

static void bond_poll_controller(struct net_device *bond_dev)
{
}

static void __bond_netpoll_cleanup(struct bonding *bond)
{
    struct slave *slave;
    int i;

    bond_for_each_slave(bond, slave, i)
        if (IS_UP(slave->dev))
            slave_disable_netpoll(slave);
}
static void bond_netpoll_cleanup(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);

    read_lock(&bond->lock);
    __bond_netpoll_cleanup(bond);
    read_unlock(&bond->lock);
}

static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, gfp_t gfp)
{
    struct bonding *bond = netdev_priv(dev);
    struct slave *slave;
    int i, err = 0;

    read_lock(&bond->lock);
    bond_for_each_slave(bond, slave, i) {
        err = slave_enable_netpoll(slave);
        if (err) {
            __bond_netpoll_cleanup(bond);
            break;
        }
    }
    read_unlock(&bond->lock);
    return err;
}

static struct netpoll_info *bond_netpoll_info(struct bonding *bond)
{
    return bond->dev->npinfo;
}

#else
static inline int slave_enable_netpoll(struct slave *slave)
{
    return 0;
}
static inline void slave_disable_netpoll(struct slave *slave)
{
}
static void bond_netpoll_cleanup(struct net_device *bond_dev)
{
}
#endif

/*---------------------------------- IOCTL ----------------------------------*/

static int bond_sethwaddr(struct net_device *bond_dev,
              struct net_device *slave_dev)
{
    pr_debug("bond_dev=%p\n", bond_dev);
    pr_debug("slave_dev=%p\n", slave_dev);
    pr_debug("slave_dev->addr_len=%d\n", slave_dev->addr_len);
    memcpy(bond_dev->dev_addr, slave_dev->dev_addr, slave_dev->addr_len);
    return 0;
}

static netdev_features_t bond_fix_features(struct net_device *dev,
    netdev_features_t features)
{
    struct slave *slave;
    struct bonding *bond = netdev_priv(dev);
    netdev_features_t mask;
    int i;

    read_lock(&bond->lock);

    if (!bond->first_slave) {
        /* Disable adding VLANs to empty bond. But why? --mq */
        features |= NETIF_F_VLAN_CHALLENGED;
        goto out;
    }

    mask = features;
    features &= ~NETIF_F_ONE_FOR_ALL;
    features |= NETIF_F_ALL_FOR_ALL;

    bond_for_each_slave(bond, slave, i) {
        features = netdev_increment_features(features,
                             slave->dev->features,
                             mask);
    }

out:
    read_unlock(&bond->lock);
    return features;
}

#define BOND_VLAN_FEATURES  (NETIF_F_ALL_CSUM | NETIF_F_SG | \
                 NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
                 NETIF_F_HIGHDMA | NETIF_F_LRO)

static void bond_compute_features(struct bonding *bond)
{
    struct slave *slave;
    struct net_device *bond_dev = bond->dev;
    netdev_features_t vlan_features = BOND_VLAN_FEATURES;
    unsigned short max_hard_header_len = ETH_HLEN;
    unsigned int gso_max_size = GSO_MAX_SIZE;
    u16 gso_max_segs = GSO_MAX_SEGS;
    int i;
    unsigned int flags, dst_release_flag = IFF_XMIT_DST_RELEASE;

    read_lock(&bond->lock);

    if (!bond->first_slave)
        goto done;

    bond_for_each_slave(bond, slave, i) {
        vlan_features = netdev_increment_features(vlan_features,
            slave->dev->vlan_features, BOND_VLAN_FEATURES);

        dst_release_flag &= slave->dev->priv_flags;
        if (slave->dev->hard_header_len > max_hard_header_len)
            max_hard_header_len = slave->dev->hard_header_len;

        gso_max_size = min(gso_max_size, slave->dev->gso_max_size);
        gso_max_segs = min(gso_max_segs, slave->dev->gso_max_segs);
    }

done:
    bond_dev->vlan_features = vlan_features;
    bond_dev->hard_header_len = max_hard_header_len;
    bond_dev->gso_max_segs = gso_max_segs;
    netif_set_gso_max_size(bond_dev, gso_max_size);

    flags = bond_dev->priv_flags & ~IFF_XMIT_DST_RELEASE;
    bond_dev->priv_flags = flags | dst_release_flag;

    read_unlock(&bond->lock);

    netdev_change_features(bond_dev);
}

static void bond_setup_by_slave(struct net_device *bond_dev,
                struct net_device *slave_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);

    bond_dev->header_ops        = slave_dev->header_ops;

    bond_dev->type          = slave_dev->type;
    bond_dev->hard_header_len   = slave_dev->hard_header_len;
    bond_dev->addr_len      = slave_dev->addr_len;

    memcpy(bond_dev->broadcast, slave_dev->broadcast,
        slave_dev->addr_len);
    bond->setup_by_slave = 1;
}

/* On bonding slaves other than the currently active slave, suppress
 * duplicates except for alb non-mcast/bcast.
 */
static bool bond_should_deliver_exact_match(struct sk_buff *skb,
                        struct slave *slave,
                        struct bonding *bond)
{
    if (bond_is_slave_inactive(slave)) {
        if (bond->params.mode == BOND_MODE_ALB &&
            skb->pkt_type != PACKET_BROADCAST &&
            skb->pkt_type != PACKET_MULTICAST)
            return false;
        return true;
    }
    return false;
}

static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb)
{
    struct sk_buff *skb = *pskb;
    struct slave *slave;
    struct bonding *bond;
    int (*recv_probe)(const struct sk_buff *, struct bonding *,
              struct slave *);
    int ret = RX_HANDLER_ANOTHER;

    skb = skb_share_check(skb, GFP_ATOMIC);
    if (unlikely(!skb))
        return RX_HANDLER_CONSUMED;

    *pskb = skb;

    slave = bond_slave_get_rcu(skb->dev);
    bond = slave->bond;

    if (bond->params.arp_interval)
        slave->dev->last_rx = jiffies;

    recv_probe = ACCESS_ONCE(bond->recv_probe);
    if (recv_probe) {
        ret = recv_probe(skb, bond, slave);
        if (ret == RX_HANDLER_CONSUMED) {
            consume_skb(skb);
            return ret;
        }
    }

    if (bond_should_deliver_exact_match(skb, slave, bond)) {
        return RX_HANDLER_EXACT;
    }

    skb->dev = bond->dev;

    if (bond->params.mode == BOND_MODE_ALB &&
        bond->dev->priv_flags & IFF_BRIDGE_PORT &&
        skb->pkt_type == PACKET_HOST) {

        if (unlikely(skb_cow_head(skb,
                      skb->data - skb_mac_header(skb)))) {
            kfree_skb(skb);
            return RX_HANDLER_CONSUMED;
        }
        memcpy(eth_hdr(skb)->h_dest, bond->dev->dev_addr, ETH_ALEN);
    }

    return ret;
}

/* enslave device <slave> to bond device <master> */
int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
    struct slave *new_slave = NULL;
    struct netdev_hw_addr *ha;
    struct sockaddr addr;
    int link_reporting;
    int res = 0;

    if (!bond->params.use_carrier && slave_dev->ethtool_ops == NULL &&
        slave_ops->ndo_do_ioctl == NULL) {
        pr_warning("%s: Warning: no link monitoring support for %s\n",
               bond_dev->name, slave_dev->name);
    }

    /* already enslaved */
    if (slave_dev->flags & IFF_SLAVE) {
        pr_debug("Error, Device was already enslaved\n");
        return -EBUSY;
    }

    /* vlan challenged mutual exclusion */
    /* no need to lock since we're protected by rtnl_lock */
    if (slave_dev->features & NETIF_F_VLAN_CHALLENGED) {
        pr_debug("%s: NETIF_F_VLAN_CHALLENGED\n", slave_dev->name);
        if (vlan_uses_dev(bond_dev)) {
            pr_err("%s: Error: cannot enslave VLAN challenged slave %s on VLAN enabled bond %s\n",
                   bond_dev->name, slave_dev->name, bond_dev->name);
            return -EPERM;
        } else {
            pr_warning("%s: Warning: enslaved VLAN challenged slave %s. Adding VLANs will be blocked as long as %s is part of bond %s\n",
                   bond_dev->name, slave_dev->name,
                   slave_dev->name, bond_dev->name);
        }
    } else {
        pr_debug("%s: ! NETIF_F_VLAN_CHALLENGED\n", slave_dev->name);
    }

    /*
     * Old ifenslave binaries are no longer supported.  These can
     * be identified with moderate accuracy by the state of the slave:
     * the current ifenslave will set the interface down prior to
     * enslaving it; the old ifenslave will not.
     */
    if ((slave_dev->flags & IFF_UP)) {
        pr_err("%s is up. This may be due to an out of date ifenslave.\n",
               slave_dev->name);
        res = -EPERM;
        goto err_undo_flags;
    }

    /* set bonding device ether type by slave - bonding netdevices are
     * created with ether_setup, so when the slave type is not ARPHRD_ETHER
     * there is a need to override some of the type dependent attribs/funcs.
     *
     * bond ether type mutual exclusion - don't allow slaves of dissimilar
     * ether type (eg ARPHRD_ETHER and ARPHRD_INFINIBAND) share the same bond
     */
    if (bond->slave_cnt == 0) {
        if (bond_dev->type != slave_dev->type) {
            pr_debug("%s: change device type from %d to %d\n",
                 bond_dev->name,
                 bond_dev->type, slave_dev->type);

            res = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE,
                               bond_dev);
            res = notifier_to_errno(res);
            if (res) {
                pr_err("%s: refused to change device type\n",
                       bond_dev->name);
                res = -EBUSY;
                goto err_undo_flags;
            }

            /* Flush unicast and multicast addresses */
            dev_uc_flush(bond_dev);
            dev_mc_flush(bond_dev);

            if (slave_dev->type != ARPHRD_ETHER)
                bond_setup_by_slave(bond_dev, slave_dev);
            else {
                ether_setup(bond_dev);
                bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
            }

            call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE,
                         bond_dev);
        }
    } else if (bond_dev->type != slave_dev->type) {
        pr_err("%s ether type (%d) is different from other slaves (%d), can not enslave it.\n",
               slave_dev->name,
               slave_dev->type, bond_dev->type);
        res = -EINVAL;
        goto err_undo_flags;
    }

    if (slave_ops->ndo_set_mac_address == NULL) {
        if (bond->slave_cnt == 0) {
            pr_warning("%s: Warning: The first slave device specified does not support setting the MAC address. Setting fail_over_mac to active.",
                   bond_dev->name);
            bond->params.fail_over_mac = BOND_FOM_ACTIVE;
        } else if (bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
            pr_err("%s: Error: The slave device specified does not support setting the MAC address, but fail_over_mac is not set to active.\n",
                   bond_dev->name);
            res = -EOPNOTSUPP;
            goto err_undo_flags;
        }
    }

    call_netdevice_notifiers(NETDEV_JOIN, slave_dev);

    /* If this is the first slave, then we need to set the master's hardware
     * address to be the same as the slave's. */
    if (is_zero_ether_addr(bond->dev->dev_addr))
        memcpy(bond->dev->dev_addr, slave_dev->dev_addr,
               slave_dev->addr_len);


    new_slave = kzalloc(sizeof(struct slave), GFP_KERNEL);
    if (!new_slave) {
        res = -ENOMEM;
        goto err_undo_flags;
    }

    /*
     * Set the new_slave's queue_id to be zero.  Queue ID mapping
     * is set via sysfs or module option if desired.
     */
    new_slave->queue_id = 0;

    /* Save slave's original mtu and then set it to match the bond */
    new_slave->original_mtu = slave_dev->mtu;
    res = dev_set_mtu(slave_dev, bond->dev->mtu);
    if (res) {
        pr_debug("Error %d calling dev_set_mtu\n", res);
        goto err_free;
    }

    /*
     * Save slave's original ("permanent") mac address for modes
     * that need it, and for restoring it upon release, and then
     * set it to the master's address
     */
    memcpy(new_slave->perm_hwaddr, slave_dev->dev_addr, ETH_ALEN);

    if (!bond->params.fail_over_mac) {
        /*
         * Set slave to master's mac address.  The application already
         * set the master's mac address to that of the first slave
         */
        memcpy(addr.sa_data, bond_dev->dev_addr, bond_dev->addr_len);
        addr.sa_family = slave_dev->type;
        res = dev_set_mac_address(slave_dev, &addr);
        if (res) {
            pr_debug("Error %d calling set_mac_address\n", res);
            goto err_restore_mtu;
        }
    }

    res = netdev_set_bond_master(slave_dev, bond_dev);
    if (res) {
        pr_debug("Error %d calling netdev_set_bond_master\n", res);
        goto err_restore_mac;
    }

    /* open the slave since the application closed it */
    res = dev_open(slave_dev);
    if (res) {
        pr_debug("Opening slave %s failed\n", slave_dev->name);
        goto err_unset_master;
    }

    new_slave->bond = bond;
    new_slave->dev = slave_dev;
    slave_dev->priv_flags |= IFF_BONDING;

    if (bond_is_lb(bond)) {
        /* bond_alb_init_slave() must be called before all other stages since
         * it might fail and we do not want to have to undo everything
         */
        res = bond_alb_init_slave(bond, new_slave);
        if (res)
            goto err_close;
    }

    /* If the mode USES_PRIMARY, then the new slave gets the
     * master's promisc (and mc) settings only if it becomes the
     * curr_active_slave, and that is taken care of later when calling
     * bond_change_active()
     */
    if (!USES_PRIMARY(bond->params.mode)) {
        /* set promiscuity level to new slave */
        if (bond_dev->flags & IFF_PROMISC) {
            res = dev_set_promiscuity(slave_dev, 1);
            if (res)
                goto err_close;
        }

        /* set allmulti level to new slave */
        if (bond_dev->flags & IFF_ALLMULTI) {
            res = dev_set_allmulti(slave_dev, 1);
            if (res)
                goto err_close;
        }

        netif_addr_lock_bh(bond_dev);
        /* upload master's mc_list to new slave */
        netdev_for_each_mc_addr(ha, bond_dev)
            dev_mc_add(slave_dev, ha->addr);
        netif_addr_unlock_bh(bond_dev);
    }

    if (bond->params.mode == BOND_MODE_8023AD) {
        /* add lacpdu mc addr to mc list */
        u8 lacpdu_multicast[ETH_ALEN] = MULTICAST_LACPDU_ADDR;

        dev_mc_add(slave_dev, lacpdu_multicast);
    }

    bond_add_vlans_on_slave(bond, slave_dev);

    write_lock_bh(&bond->lock);

    bond_attach_slave(bond, new_slave);

    new_slave->delay = 0;
    new_slave->link_failure_count = 0;

    write_unlock_bh(&bond->lock);

    bond_compute_features(bond);

    read_lock(&bond->lock);

    new_slave->last_arp_rx = jiffies -
        (msecs_to_jiffies(bond->params.arp_interval) + 1);

    if (bond->params.miimon && !bond->params.use_carrier) {
        link_reporting = bond_check_dev_link(bond, slave_dev, 1);

        if ((link_reporting == -1) && !bond->params.arp_interval) {
            /*
             * miimon is set but a bonded network driver
             * does not support ETHTOOL/MII and
             * arp_interval is not set.  Note: if
             * use_carrier is enabled, we will never go
             * here (because netif_carrier is always
             * supported); thus, we don't need to change
             * the messages for netif_carrier.
             */
            pr_warning("%s: Warning: MII and ETHTOOL support not available for interface %s, and arp_interval/arp_ip_target module parameters not specified, thus bonding will not detect link failures! see bonding.txt for details.\n",
                   bond_dev->name, slave_dev->name);
        } else if (link_reporting == -1) {
            /* unable get link status using mii/ethtool */
            pr_warning("%s: Warning: can't get link status from interface %s; the network driver associated with this interface does not support MII or ETHTOOL link status reporting, thus miimon has no effect on this interface.\n",
                   bond_dev->name, slave_dev->name);
        }
    }

    /* check for initial state */
    if (bond->params.miimon) {
        if (bond_check_dev_link(bond, slave_dev, 0) == BMSR_LSTATUS) {
            if (bond->params.updelay) {
                new_slave->link = BOND_LINK_BACK;
                new_slave->delay = bond->params.updelay;
            } else {
                new_slave->link = BOND_LINK_UP;
            }
        } else {
            new_slave->link = BOND_LINK_DOWN;
        }
    } else if (bond->params.arp_interval) {
        new_slave->link = (netif_carrier_ok(slave_dev) ?
            BOND_LINK_UP : BOND_LINK_DOWN);
    } else {
        new_slave->link = BOND_LINK_UP;
    }

    if (new_slave->link != BOND_LINK_DOWN)
        new_slave->jiffies = jiffies;
    pr_debug("Initial state of slave_dev is BOND_LINK_%s\n",
        new_slave->link == BOND_LINK_DOWN ? "DOWN" :
            (new_slave->link == BOND_LINK_UP ? "UP" : "BACK"));

    bond_update_speed_duplex(new_slave);

    if (USES_PRIMARY(bond->params.mode) && bond->params.primary[0]) {
        /* if there is a primary slave, remember it */
        if (strcmp(bond->params.primary, new_slave->dev->name) == 0) {
            bond->primary_slave = new_slave;
            bond->force_primary = true;
        }
    }

    write_lock_bh(&bond->curr_slave_lock);

    switch (bond->params.mode) {
    case BOND_MODE_ACTIVEBACKUP:
        bond_set_slave_inactive_flags(new_slave);
        bond_select_active_slave(bond);
        break;
    case BOND_MODE_8023AD:
        /* in 802.3ad mode, the internal mechanism
         * will activate the slaves in the selected
         * aggregator
         */
        bond_set_slave_inactive_flags(new_slave);
        /* if this is the first slave */
        if (bond->slave_cnt == 1) {
            SLAVE_AD_INFO(new_slave).id = 1;
            /* Initialize AD with the number of times that the AD timer is called in 1 second
             * can be called only after the mac address of the bond is set
             */
            bond_3ad_initialize(bond, 1000/AD_TIMER_INTERVAL);
        } else {
            SLAVE_AD_INFO(new_slave).id =
                SLAVE_AD_INFO(new_slave->prev).id + 1;
        }

        bond_3ad_bind_slave(new_slave);
        break;
    case BOND_MODE_TLB:
    case BOND_MODE_ALB:
        bond_set_active_slave(new_slave);
        bond_set_slave_inactive_flags(new_slave);
        bond_select_active_slave(bond);
        break;
    default:
        pr_debug("This slave is always active in trunk mode\n");

        /* always active in trunk mode */
        bond_set_active_slave(new_slave);

        /* In trunking mode there is little meaning to curr_active_slave
         * anyway (it holds no special properties of the bond device),
         * so we can change it without calling change_active_interface()
         */
        if (!bond->curr_active_slave)
            bond->curr_active_slave = new_slave;

        break;
    } /* switch(bond_mode) */

    write_unlock_bh(&bond->curr_slave_lock);

    bond_set_carrier(bond);

#ifdef CONFIG_NET_POLL_CONTROLLER
    slave_dev->npinfo = bond_netpoll_info(bond);
    if (slave_dev->npinfo) {
        if (slave_enable_netpoll(new_slave)) {
            read_unlock(&bond->lock);
            pr_info("Error, %s: master_dev is using netpoll, "
                 "but new slave device does not support netpoll.\n",
                 bond_dev->name);
            res = -EBUSY;
            goto err_detach;
        }
    }
#endif

    read_unlock(&bond->lock);

    res = bond_create_slave_symlinks(bond_dev, slave_dev);
    if (res)
        goto err_detach;

    res = netdev_rx_handler_register(slave_dev, bond_handle_frame,
                     new_slave);
    if (res) {
        pr_debug("Error %d calling netdev_rx_handler_register\n", res);
        goto err_dest_symlinks;
    }

    pr_info("%s: enslaving %s as a%s interface with a%s link.\n",
        bond_dev->name, slave_dev->name,
        bond_is_active_slave(new_slave) ? "n active" : " backup",
        new_slave->link != BOND_LINK_DOWN ? "n up" : " down");

    /* enslave is successful */
    return 0;

/* Undo stages on error */
err_dest_symlinks:
    bond_destroy_slave_symlinks(bond_dev, slave_dev);

err_detach:
    write_lock_bh(&bond->lock);
    bond_detach_slave(bond, new_slave);
    write_unlock_bh(&bond->lock);

err_close:
    dev_close(slave_dev);

err_unset_master:
    netdev_set_bond_master(slave_dev, NULL);

err_restore_mac:
    if (!bond->params.fail_over_mac) {
        /* XXX TODO - fom follow mode needs to change master's
         * MAC if this slave's MAC is in use by the bond, or at
         * least print a warning.
         */
        memcpy(addr.sa_data, new_slave->perm_hwaddr, ETH_ALEN);
        addr.sa_family = slave_dev->type;
        dev_set_mac_address(slave_dev, &addr);
    }

err_restore_mtu:
    dev_set_mtu(slave_dev, new_slave->original_mtu);

err_free:
    kfree(new_slave);

err_undo_flags:
    bond_compute_features(bond);

    return res;
}

/*
 * Try to release the slave device <slave> from the bond device <master>
 * It is legal to access curr_active_slave without a lock because all the function
 * is write-locked.
 *
 * The rules for slave state should be:
 *   for Active/Backup:
 *     Active stays on all backups go down
 *   for Bonded connections:
 *     The first up interface should be left on and all others downed.
 */
int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave, *oldcurrent;
    struct sockaddr addr;
    netdev_features_t old_features = bond_dev->features;

    /* slave is not a slave or master is not master of this slave */
    if (!(slave_dev->flags & IFF_SLAVE) ||
        (slave_dev->master != bond_dev)) {
        pr_err("%s: Error: cannot release %s.\n",
               bond_dev->name, slave_dev->name);
        return -EINVAL;
    }

    block_netpoll_tx();
    call_netdevice_notifiers(NETDEV_RELEASE, bond_dev);
    write_lock_bh(&bond->lock);

    slave = bond_get_slave_by_dev(bond, slave_dev);
    if (!slave) {
        /* not a slave of this bond */
        pr_info("%s: %s not enslaved\n",
            bond_dev->name, slave_dev->name);
        write_unlock_bh(&bond->lock);
        unblock_netpoll_tx();
        return -EINVAL;
    }

    /* unregister rx_handler early so bond_handle_frame wouldn't be called
     * for this slave anymore.
     */
    netdev_rx_handler_unregister(slave_dev);
    write_unlock_bh(&bond->lock);
    synchronize_net();
    write_lock_bh(&bond->lock);

    if (!bond->params.fail_over_mac) {
        if (ether_addr_equal(bond_dev->dev_addr, slave->perm_hwaddr) &&
            bond->slave_cnt > 1)
            pr_warning("%s: Warning: the permanent HWaddr of %s - %pM - is still in use by %s. Set the HWaddr of %s to a different address to avoid conflicts.\n",
                   bond_dev->name, slave_dev->name,
                   slave->perm_hwaddr,
                   bond_dev->name, slave_dev->name);
    }

    /* Inform AD package of unbinding of slave. */
    if (bond->params.mode == BOND_MODE_8023AD) {
        /* must be called before the slave is
         * detached from the list
         */
        bond_3ad_unbind_slave(slave);
    }

    pr_info("%s: releasing %s interface %s\n",
        bond_dev->name,
        bond_is_active_slave(slave) ? "active" : "backup",
        slave_dev->name);

    oldcurrent = bond->curr_active_slave;

    bond->current_arp_slave = NULL;

    /* release the slave from its bond */
    bond_detach_slave(bond, slave);

    if (bond->primary_slave == slave)
        bond->primary_slave = NULL;

    if (oldcurrent == slave)
        bond_change_active_slave(bond, NULL);

    if (bond_is_lb(bond)) {
        /* Must be called only after the slave has been
         * detached from the list and the curr_active_slave
         * has been cleared (if our_slave == old_current),
         * but before a new active slave is selected.
         */
        write_unlock_bh(&bond->lock);
        bond_alb_deinit_slave(bond, slave);
        write_lock_bh(&bond->lock);
    }

    if (oldcurrent == slave) {
        /*
         * Note that we hold RTNL over this sequence, so there
         * is no concern that another slave add/remove event
         * will interfere.
         */
        write_unlock_bh(&bond->lock);
        read_lock(&bond->lock);
        write_lock_bh(&bond->curr_slave_lock);

        bond_select_active_slave(bond);

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

    if (bond->slave_cnt == 0) {
        bond_set_carrier(bond);

        /* if the last slave was removed, zero the mac address
         * of the master so it will be set by the application
         * to the mac address of the first slave
         */
        memset(bond_dev->dev_addr, 0, bond_dev->addr_len);

        if (bond_vlan_used(bond)) {
            pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n",
                   bond_dev->name, bond_dev->name);
            pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n",
                   bond_dev->name);
        }
    }

    write_unlock_bh(&bond->lock);
    unblock_netpoll_tx();

    if (bond->slave_cnt == 0)
        call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);

    bond_compute_features(bond);
    if (!(bond_dev->features & NETIF_F_VLAN_CHALLENGED) &&
        (old_features & NETIF_F_VLAN_CHALLENGED))
        pr_info("%s: last VLAN challenged slave %s left bond %s. VLAN blocking is removed\n",
            bond_dev->name, slave_dev->name, bond_dev->name);

    /* must do this from outside any spinlocks */
    bond_destroy_slave_symlinks(bond_dev, slave_dev);

    bond_del_vlans_from_slave(bond, slave_dev);

    /* If the mode USES_PRIMARY, then we should only remove its
     * promisc and mc settings if it was the curr_active_slave, but that was
     * already taken care of above when we detached the slave
     */
    if (!USES_PRIMARY(bond->params.mode)) {
        /* unset promiscuity level from slave */
        if (bond_dev->flags & IFF_PROMISC)
            dev_set_promiscuity(slave_dev, -1);

        /* unset allmulti level from slave */
        if (bond_dev->flags & IFF_ALLMULTI)
            dev_set_allmulti(slave_dev, -1);

        /* flush master's mc_list from slave */
        netif_addr_lock_bh(bond_dev);
        bond_mc_list_flush(bond_dev, slave_dev);
        netif_addr_unlock_bh(bond_dev);
    }

    netdev_set_bond_master(slave_dev, NULL);

    slave_disable_netpoll(slave);

    /* close slave before restoring its mac address */
    dev_close(slave_dev);

    if (bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
        /* restore original ("permanent") mac address */
        memcpy(addr.sa_data, slave->perm_hwaddr, ETH_ALEN);
        addr.sa_family = slave_dev->type;
        dev_set_mac_address(slave_dev, &addr);
    }

    dev_set_mtu(slave_dev, slave->original_mtu);

    slave_dev->priv_flags &= ~IFF_BONDING;

    kfree(slave);

    return 0;  /* deletion OK */
}

/*
* First release a slave and then destroy the bond if no more slaves are left.
* Must be under rtnl_lock when this function is called.
*/
static int  bond_release_and_destroy(struct net_device *bond_dev,
                     struct net_device *slave_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    int ret;

    ret = bond_release(bond_dev, slave_dev);
    if ((ret == 0) && (bond->slave_cnt == 0)) {
        bond_dev->priv_flags |= IFF_DISABLE_NETPOLL;
        pr_info("%s: destroying bond %s.\n",
            bond_dev->name, bond_dev->name);
        unregister_netdevice(bond_dev);
    }
    return ret;
}

/*
 * This function releases all slaves.
 */
static int bond_release_all(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave;
    struct net_device *slave_dev;
    struct sockaddr addr;

    write_lock_bh(&bond->lock);

    netif_carrier_off(bond_dev);

    if (bond->slave_cnt == 0)
        goto out;

    bond->current_arp_slave = NULL;
    bond->primary_slave = NULL;
    bond_change_active_slave(bond, NULL);

    while ((slave = bond->first_slave) != NULL) {
        /* Inform AD package of unbinding of slave
         * before slave is detached from the list.
         */
        if (bond->params.mode == BOND_MODE_8023AD)
            bond_3ad_unbind_slave(slave);

        slave_dev = slave->dev;
        bond_detach_slave(bond, slave);

        /* now that the slave is detached, unlock and perform
         * all the undo steps that should not be called from
         * within a lock.
         */
        write_unlock_bh(&bond->lock);

        /* unregister rx_handler early so bond_handle_frame wouldn't
         * be called for this slave anymore.
         */
        netdev_rx_handler_unregister(slave_dev);
        synchronize_net();

        if (bond_is_lb(bond)) {
            /* must be called only after the slave
             * has been detached from the list
             */
            bond_alb_deinit_slave(bond, slave);
        }

        bond_destroy_slave_symlinks(bond_dev, slave_dev);
        bond_del_vlans_from_slave(bond, slave_dev);

        /* If the mode USES_PRIMARY, then we should only remove its
         * promisc and mc settings if it was the curr_active_slave, but that was
         * already taken care of above when we detached the slave
         */
        if (!USES_PRIMARY(bond->params.mode)) {
            /* unset promiscuity level from slave */
            if (bond_dev->flags & IFF_PROMISC)
                dev_set_promiscuity(slave_dev, -1);

            /* unset allmulti level from slave */
            if (bond_dev->flags & IFF_ALLMULTI)
                dev_set_allmulti(slave_dev, -1);

            /* flush master's mc_list from slave */
            netif_addr_lock_bh(bond_dev);
            bond_mc_list_flush(bond_dev, slave_dev);
            netif_addr_unlock_bh(bond_dev);
        }

        netdev_set_bond_master(slave_dev, NULL);

        slave_disable_netpoll(slave);

        /* close slave before restoring its mac address */
        dev_close(slave_dev);

        if (!bond->params.fail_over_mac) {
            /* restore original ("permanent") mac address*/
            memcpy(addr.sa_data, slave->perm_hwaddr, ETH_ALEN);
            addr.sa_family = slave_dev->type;
            dev_set_mac_address(slave_dev, &addr);
        }

        kfree(slave);

        /* re-acquire the lock before getting the next slave */
        write_lock_bh(&bond->lock);
    }

    /* zero the mac address of the master so it will be
     * set by the application to the mac address of the
     * first slave
     */
    memset(bond_dev->dev_addr, 0, bond_dev->addr_len);

    if (bond_vlan_used(bond)) {
        pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n",
               bond_dev->name, bond_dev->name);
        pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n",
               bond_dev->name);
    }

    pr_info("%s: released all slaves\n", bond_dev->name);

out:
    write_unlock_bh(&bond->lock);

    bond_compute_features(bond);

    return 0;
}

/*
 * This function changes the active slave to slave <slave_dev>.
 * It returns -EINVAL in the following cases.
 *  - <slave_dev> is not found in the list.
 *  - There is not active slave now.
 *  - <slave_dev> is already active.
 *  - The link state of <slave_dev> is not BOND_LINK_UP.
 *  - <slave_dev> is not running.
 * In these cases, this function does nothing.
 * In the other cases, current_slave pointer is changed and 0 is returned.
 */
static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_device *slave_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *old_active = NULL;
    struct slave *new_active = NULL;
    int res = 0;

    if (!USES_PRIMARY(bond->params.mode))
        return -EINVAL;

    /* Verify that master_dev is indeed the master of slave_dev */
    if (!(slave_dev->flags & IFF_SLAVE) || (slave_dev->master != bond_dev))
        return -EINVAL;

    read_lock(&bond->lock);

    read_lock(&bond->curr_slave_lock);
    old_active = bond->curr_active_slave;
    read_unlock(&bond->curr_slave_lock);

    new_active = bond_get_slave_by_dev(bond, slave_dev);

    /*
     * Changing to the current active: do nothing; return success.
     */
    if (new_active && (new_active == old_active)) {
        read_unlock(&bond->lock);
        return 0;
    }

    if ((new_active) &&
        (old_active) &&
        (new_active->link == BOND_LINK_UP) &&
        IS_UP(new_active->dev)) {
        block_netpoll_tx();
        write_lock_bh(&bond->curr_slave_lock);
        bond_change_active_slave(bond, new_active);
        write_unlock_bh(&bond->curr_slave_lock);
        unblock_netpoll_tx();
    } else
        res = -EINVAL;

    read_unlock(&bond->lock);

    return res;
}

static int bond_info_query(struct net_device *bond_dev, struct ifbond *info)
{
    struct bonding *bond = netdev_priv(bond_dev);

    info->bond_mode = bond->params.mode;
    info->miimon = bond->params.miimon;

    read_lock(&bond->lock);
    info->num_slaves = bond->slave_cnt;
    read_unlock(&bond->lock);

    return 0;
}

static int bond_slave_info_query(struct net_device *bond_dev, struct ifslave *info)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave;
    int i, res = -ENODEV;

    read_lock(&bond->lock);

    bond_for_each_slave(bond, slave, i) {
        if (i == (int)info->slave_id) {
            res = 0;
            strcpy(info->slave_name, slave->dev->name);
            info->link = slave->link;
            info->state = bond_slave_state(slave);
            info->link_failure_count = slave->link_failure_count;
            break;
        }
    }

    read_unlock(&bond->lock);

    return res;
}

/*-------------------------------- Monitoring -------------------------------*/


static int bond_miimon_inspect(struct bonding *bond)
{
    struct slave *slave;
    int i, link_state, commit = 0;
    bool ignore_updelay;

    ignore_updelay = !bond->curr_active_slave ? true : false;

    bond_for_each_slave(bond, slave, i) {
        slave->new_link = BOND_LINK_NOCHANGE;

        link_state = bond_check_dev_link(bond, slave->dev, 0);

        switch (slave->link) {
        case BOND_LINK_UP:
            if (link_state)
                continue;

            slave->link = BOND_LINK_FAIL;
            slave->delay = bond->params.downdelay;
            if (slave->delay) {
                pr_info("%s: link status down for %sinterface %s, disabling it in %d ms.\n",
                    bond->dev->name,
                    (bond->params.mode ==
                     BOND_MODE_ACTIVEBACKUP) ?
                    (bond_is_active_slave(slave) ?
                     "active " : "backup ") : "",
                    slave->dev->name,
                    bond->params.downdelay * bond->params.miimon);
            }
            /*FALLTHRU*/
        case BOND_LINK_FAIL:
            if (link_state) {
                /*
                 * recovered before downdelay expired
                 */
                slave->link = BOND_LINK_UP;
                slave->jiffies = jiffies;
                pr_info("%s: link status up again after %d ms for interface %s.\n",
                    bond->dev->name,
                    (bond->params.downdelay - slave->delay) *
                    bond->params.miimon,
                    slave->dev->name);
                continue;
            }

            if (slave->delay <= 0) {
                slave->new_link = BOND_LINK_DOWN;
                commit++;
                continue;
            }

            slave->delay--;
            break;

        case BOND_LINK_DOWN:
            if (!link_state)
                continue;

            slave->link = BOND_LINK_BACK;
            slave->delay = bond->params.updelay;

            if (slave->delay) {
                pr_info("%s: link status up for interface %s, enabling it in %d ms.\n",
                    bond->dev->name, slave->dev->name,
                    ignore_updelay ? 0 :
                    bond->params.updelay *
                    bond->params.miimon);
            }
            /*FALLTHRU*/
        case BOND_LINK_BACK:
            if (!link_state) {
                slave->link = BOND_LINK_DOWN;
                pr_info("%s: link status down again after %d ms for interface %s.\n",
                    bond->dev->name,
                    (bond->params.updelay - slave->delay) *
                    bond->params.miimon,
                    slave->dev->name);

                continue;
            }

            if (ignore_updelay)
                slave->delay = 0;

            if (slave->delay <= 0) {
                slave->new_link = BOND_LINK_UP;
                commit++;
                ignore_updelay = false;
                continue;
            }

            slave->delay--;
            break;
        }
    }

    return commit;
}

static void bond_miimon_commit(struct bonding *bond)
{
    struct slave *slave;
    int i;

    bond_for_each_slave(bond, slave, i) {
        switch (slave->new_link) {
        case BOND_LINK_NOCHANGE:
            continue;

        case BOND_LINK_UP:
            slave->link = BOND_LINK_UP;
            slave->jiffies = jiffies;

            if (bond->params.mode == BOND_MODE_8023AD) {
                /* prevent it from being the active one */
                bond_set_backup_slave(slave);
            } else if (bond->params.mode != BOND_MODE_ACTIVEBACKUP) {
                /* make it immediately active */
                bond_set_active_slave(slave);
            } else if (slave != bond->primary_slave) {
                /* prevent it from being the active one */
                bond_set_backup_slave(slave);
            }

            bond_update_speed_duplex(slave);

            pr_info("%s: link status definitely up for interface %s, %u Mbps %s duplex.\n",
                bond->dev->name, slave->dev->name,
                slave->speed, slave->duplex ? "full" : "half");

            /* notify ad that the link status has changed */
            if (bond->params.mode == BOND_MODE_8023AD)
                bond_3ad_handle_link_change(slave, BOND_LINK_UP);

            if (bond_is_lb(bond))
                bond_alb_handle_link_change(bond, slave,
                                BOND_LINK_UP);

            if (!bond->curr_active_slave ||
                (slave == bond->primary_slave))
                goto do_failover;

            continue;

        case BOND_LINK_DOWN:
            if (slave->link_failure_count < UINT_MAX)
                slave->link_failure_count++;

            slave->link = BOND_LINK_DOWN;

            if (bond->params.mode == BOND_MODE_ACTIVEBACKUP ||
                bond->params.mode == BOND_MODE_8023AD)
                bond_set_slave_inactive_flags(slave);

            pr_info("%s: link status definitely down for interface %s, disabling it\n",
                bond->dev->name, slave->dev->name);

            if (bond->params.mode == BOND_MODE_8023AD)
                bond_3ad_handle_link_change(slave,
                                BOND_LINK_DOWN);

            if (bond_is_lb(bond))
                bond_alb_handle_link_change(bond, slave,
                                BOND_LINK_DOWN);

            if (slave == bond->curr_active_slave)
                goto do_failover;

            continue;

        default:
            pr_err("%s: invalid new link %d on slave %s\n",
                   bond->dev->name, slave->new_link,
                   slave->dev->name);
            slave->new_link = BOND_LINK_NOCHANGE;

            continue;
        }

do_failover:
        ASSERT_RTNL();
        block_netpoll_tx();
        write_lock_bh(&bond->curr_slave_lock);
        bond_select_active_slave(bond);
        write_unlock_bh(&bond->curr_slave_lock);
        unblock_netpoll_tx();
    }

    bond_set_carrier(bond);
}

/*
 * bond_mii_monitor
 *
 * Really a wrapper that splits the mii monitor into two phases: an
 * inspection, then (if inspection indicates something needs to be done)
 * an acquisition of appropriate locks followed by a commit phase to
 * implement whatever link state changes are indicated.
 */
void bond_mii_monitor(struct work_struct *work)
{
    struct bonding *bond = container_of(work, struct bonding,
                        mii_work.work);
    bool should_notify_peers = false;
    unsigned long delay;

    read_lock(&bond->lock);

    delay = msecs_to_jiffies(bond->params.miimon);

    if (bond->slave_cnt == 0)
        goto re_arm;

    should_notify_peers = bond_should_notify_peers(bond);

    if (bond_miimon_inspect(bond)) {
        read_unlock(&bond->lock);

        /* Race avoidance with bond_close cancel of workqueue */
        if (!rtnl_trylock()) {
            read_lock(&bond->lock);
            delay = 1;
            should_notify_peers = false;
            goto re_arm;
        }

        read_lock(&bond->lock);

        bond_miimon_commit(bond);

        read_unlock(&bond->lock);
        rtnl_unlock();  /* might sleep, hold no other locks */
        read_lock(&bond->lock);
    }

re_arm:
    if (bond->params.miimon)
        queue_delayed_work(bond->wq, &bond->mii_work, delay);

    read_unlock(&bond->lock);

    if (should_notify_peers) {
        if (!rtnl_trylock()) {
            read_lock(&bond->lock);
            bond->send_peer_notif++;
            read_unlock(&bond->lock);
            return;
        }
        call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);
        rtnl_unlock();
    }
}

static int bond_has_this_ip(struct bonding *bond, __be32 ip)
{
    struct vlan_entry *vlan;
    struct net_device *vlan_dev;

    if (ip == bond_confirm_addr(bond->dev, 0, ip))
        return 1;

    list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
        rcu_read_lock();
        vlan_dev = __vlan_find_dev_deep(bond->dev, vlan->vlan_id);
        rcu_read_unlock();
        if (vlan_dev && ip == bond_confirm_addr(vlan_dev, 0, ip))
            return 1;
    }

    return 0;
}

/*
 * We go to the (large) trouble of VLAN tagging ARP frames because
 * switches in VLAN mode (especially if ports are configured as
 * "native" to a VLAN) might not pass non-tagged frames.
 */
static void bond_arp_send(struct net_device *slave_dev, int arp_op, __be32 dest_ip, __be32 src_ip, unsigned short vlan_id)
{
    struct sk_buff *skb;

    pr_debug("arp %d on slave %s: dst %x src %x vid %d\n", arp_op,
         slave_dev->name, dest_ip, src_ip, vlan_id);

    skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
             NULL, slave_dev->dev_addr, NULL);

    if (!skb) {
        pr_err("ARP packet allocation failed\n");
        return;
    }
    if (vlan_id) {
        skb = vlan_put_tag(skb, vlan_id);
        if (!skb) {
            pr_err("failed to insert VLAN tag\n");
            return;
        }
    }
    arp_xmit(skb);
}


static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
{
    int i, vlan_id;
    __be32 *targets = bond->params.arp_targets;
    struct vlan_entry *vlan;
    struct net_device *vlan_dev = NULL;
    struct rtable *rt;

    for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
        __be32 addr;
        if (!targets[i])
            break;
        pr_debug("basa: target %x\n", targets[i]);
        if (!bond_vlan_used(bond)) {
            pr_debug("basa: empty vlan: arp_send\n");
            addr = bond_confirm_addr(bond->dev, targets[i], 0);
            bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                      addr, 0);
            continue;
        }

        /*
         * If VLANs are configured, we do a route lookup to
         * determine which VLAN interface would be used, so we
         * can tag the ARP with the proper VLAN tag.
         */
        rt = ip_route_output(dev_net(bond->dev), targets[i], 0,
                     RTO_ONLINK, 0);
        if (IS_ERR(rt)) {
            if (net_ratelimit()) {
                pr_warning("%s: no route to arp_ip_target %pI4\n",
                       bond->dev->name, &targets[i]);
            }
            continue;
        }

        /*
         * This target is not on a VLAN
         */
        if (rt->dst.dev == bond->dev) {
            ip_rt_put(rt);
            pr_debug("basa: rtdev == bond->dev: arp_send\n");
            addr = bond_confirm_addr(bond->dev, targets[i], 0);
            bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                      addr, 0);
            continue;
        }

        vlan_id = 0;
        list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
            rcu_read_lock();
            vlan_dev = __vlan_find_dev_deep(bond->dev,
                            vlan->vlan_id);
            rcu_read_unlock();
            if (vlan_dev == rt->dst.dev) {
                vlan_id = vlan->vlan_id;
                pr_debug("basa: vlan match on %s %d\n",
                       vlan_dev->name, vlan_id);
                break;
            }
        }

        if (vlan_id && vlan_dev) {
            ip_rt_put(rt);
            addr = bond_confirm_addr(vlan_dev, targets[i], 0);
            bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                      addr, vlan_id);
            continue;
        }

        if (net_ratelimit()) {
            pr_warning("%s: no path to arp_ip_target %pI4 via rt.dev %s\n",
                   bond->dev->name, &targets[i],
                   rt->dst.dev ? rt->dst.dev->name : "NULL");
        }
        ip_rt_put(rt);
    }
}

static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32 sip, __be32 tip)
{
    int i;
    __be32 *targets = bond->params.arp_targets;

    for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
        pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip) %d\n",
             &sip, &tip, i, &targets[i],
             bond_has_this_ip(bond, tip));
        if (sip == targets[i]) {
            if (bond_has_this_ip(bond, tip))
                slave->last_arp_rx = jiffies;
            return;
        }
    }
}

static int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
            struct slave *slave)
{
    struct arphdr *arp = (struct arphdr *)skb->data;
    unsigned char *arp_ptr;
    __be32 sip, tip;
    int alen;

    if (skb->protocol != __cpu_to_be16(ETH_P_ARP))
        return RX_HANDLER_ANOTHER;

    read_lock(&bond->lock);
    alen = arp_hdr_len(bond->dev);

    pr_debug("bond_arp_rcv: bond %s skb->dev %s\n",
         bond->dev->name, skb->dev->name);

    if (alen > skb_headlen(skb)) {
        arp = kmalloc(alen, GFP_ATOMIC);
        if (!arp)
            goto out_unlock;
        if (skb_copy_bits(skb, 0, arp, alen) < 0)
            goto out_unlock;
    }

    if (arp->ar_hln != bond->dev->addr_len ||
        skb->pkt_type == PACKET_OTHERHOST ||
        skb->pkt_type == PACKET_LOOPBACK ||
        arp->ar_hrd != htons(ARPHRD_ETHER) ||
        arp->ar_pro != htons(ETH_P_IP) ||
        arp->ar_pln != 4)
        goto out_unlock;

    arp_ptr = (unsigned char *)(arp + 1);
    arp_ptr += bond->dev->addr_len;
    memcpy(&sip, arp_ptr, 4);
    arp_ptr += 4 + bond->dev->addr_len;
    memcpy(&tip, arp_ptr, 4);

    pr_debug("bond_arp_rcv: %s %s/%d av %d sv %d sip %pI4 tip %pI4\n",
         bond->dev->name, slave->dev->name, bond_slave_state(slave),
         bond->params.arp_validate, slave_do_arp_validate(bond, slave),
         &sip, &tip);

    /*
     * Backup slaves won't see the ARP reply, but do come through
     * here for each ARP probe (so we swap the sip/tip to validate
     * the probe).  In a "redundant switch, common router" type of
     * configuration, the ARP probe will (hopefully) travel from
     * the active, through one switch, the router, then the other
     * switch before reaching the backup.
     */
    if (bond_is_active_slave(slave))
        bond_validate_arp(bond, slave, sip, tip);
    else
        bond_validate_arp(bond, slave, tip, sip);

out_unlock:
    read_unlock(&bond->lock);
    if (arp != (struct arphdr *)skb->data)
        kfree(arp);
    return RX_HANDLER_ANOTHER;
}

/*
 * this function is called regularly to monitor each slave's link
 * ensuring that traffic is being sent and received when arp monitoring
 * is used in load-balancing mode. if the adapter has been dormant, then an
 * arp is transmitted to generate traffic. see activebackup_arp_monitor for
 * arp monitoring in active backup mode.
 */
void bond_loadbalance_arp_mon(struct work_struct *work)
{
    struct bonding *bond = container_of(work, struct bonding,
                        arp_work.work);
    struct slave *slave, *oldcurrent;
    int do_failover = 0;
    int delta_in_ticks, extra_ticks;
    int i;

    read_lock(&bond->lock);

    delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
    extra_ticks = delta_in_ticks / 2;

    if (bond->slave_cnt == 0)
        goto re_arm;

    read_lock(&bond->curr_slave_lock);
    oldcurrent = bond->curr_active_slave;
    read_unlock(&bond->curr_slave_lock);

    /* see if any of the previous devices are up now (i.e. they have
     * xmt and rcv traffic). the curr_active_slave does not come into
     * the picture unless it is null. also, slave->jiffies is not needed
     * here because we send an arp on each slave and give a slave as
     * long as it needs to get the tx/rx within the delta.
     * TODO: what about up/down delay in arp mode? it wasn't here before
     *       so it can wait
     */
    bond_for_each_slave(bond, slave, i) {
        unsigned long trans_start = dev_trans_start(slave->dev);

        if (slave->link != BOND_LINK_UP) {
            if (time_in_range(jiffies,
                trans_start - delta_in_ticks,
                trans_start + delta_in_ticks + extra_ticks) &&
                time_in_range(jiffies,
                slave->dev->last_rx - delta_in_ticks,
                slave->dev->last_rx + delta_in_ticks + extra_ticks)) {

                slave->link  = BOND_LINK_UP;
                bond_set_active_slave(slave);

                /* primary_slave has no meaning in round-robin
                 * mode. the window of a slave being up and
                 * curr_active_slave being null after enslaving
                 * is closed.
                 */
                if (!oldcurrent) {
                    pr_info("%s: link status definitely up for interface %s, ",
                        bond->dev->name,
                        slave->dev->name);
                    do_failover = 1;
                } else {
                    pr_info("%s: interface %s is now up\n",
                        bond->dev->name,
                        slave->dev->name);
                }
            }
        } else {
            /* slave->link == BOND_LINK_UP */

            /* not all switches will respond to an arp request
             * when the source ip is 0, so don't take the link down
             * if we don't know our ip yet
             */
            if (!time_in_range(jiffies,
                trans_start - delta_in_ticks,
                trans_start + 2 * delta_in_ticks + extra_ticks) ||
                !time_in_range(jiffies,
                slave->dev->last_rx - delta_in_ticks,
                slave->dev->last_rx + 2 * delta_in_ticks + extra_ticks)) {

                slave->link  = BOND_LINK_DOWN;
                bond_set_backup_slave(slave);

                if (slave->link_failure_count < UINT_MAX)
                    slave->link_failure_count++;

                pr_info("%s: interface %s is now down.\n",
                    bond->dev->name,
                    slave->dev->name);

                if (slave == oldcurrent)
                    do_failover = 1;
            }
        }

        /* note: if switch is in round-robin mode, all links
         * must tx arp to ensure all links rx an arp - otherwise
         * links may oscillate or not come up at all; if switch is
         * in something like xor mode, there is nothing we can
         * do - all replies will be rx'ed on same link causing slaves
         * to be unstable during low/no traffic periods
         */
        if (IS_UP(slave->dev))
            bond_arp_send_all(bond, slave);
    }

    if (do_failover) {
        block_netpoll_tx();
        write_lock_bh(&bond->curr_slave_lock);

        bond_select_active_slave(bond);

        write_unlock_bh(&bond->curr_slave_lock);
        unblock_netpoll_tx();
    }

re_arm:
    if (bond->params.arp_interval)
        queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);

    read_unlock(&bond->lock);
}

/*
 * Called to inspect slaves for active-backup mode ARP monitor link state
 * changes.  Sets new_link in slaves to specify what action should take
 * place for the slave.  Returns 0 if no changes are found, >0 if changes
 * to link states must be committed.
 *
 * Called with bond->lock held for read.
 */
static int bond_ab_arp_inspect(struct bonding *bond, int delta_in_ticks)
{
    struct slave *slave;
    int i, commit = 0;
    unsigned long trans_start;
    int extra_ticks;

    /* All the time comparisons below need some extra time. Otherwise, on
     * fast networks the ARP probe/reply may arrive within the same jiffy
     * as it was sent.  Then, the next time the ARP monitor is run, one
     * arp_interval will already have passed in the comparisons.
     */
    extra_ticks = delta_in_ticks / 2;

    bond_for_each_slave(bond, slave, i) {
        slave->new_link = BOND_LINK_NOCHANGE;

        if (slave->link != BOND_LINK_UP) {
            if (time_in_range(jiffies,
                slave_last_rx(bond, slave) - delta_in_ticks,
                slave_last_rx(bond, slave) + delta_in_ticks + extra_ticks)) {

                slave->new_link = BOND_LINK_UP;
                commit++;
            }

            continue;
        }

        /*
         * Give slaves 2*delta after being enslaved or made
         * active.  This avoids bouncing, as the last receive
         * times need a full ARP monitor cycle to be updated.
         */
        if (time_in_range(jiffies,
                  slave->jiffies - delta_in_ticks,
                  slave->jiffies + 2 * delta_in_ticks + extra_ticks))
            continue;

        /*
         * Backup slave is down if:
         * - No current_arp_slave AND
         * - more than 3*delta since last receive AND
         * - the bond has an IP address
         *
         * Note: a non-null current_arp_slave indicates
         * the curr_active_slave went down and we are
         * searching for a new one; under this condition
         * we only take the curr_active_slave down - this
         * gives each slave a chance to tx/rx traffic
         * before being taken out
         */
        if (!bond_is_active_slave(slave) &&
            !bond->current_arp_slave &&
            !time_in_range(jiffies,
            slave_last_rx(bond, slave) - delta_in_ticks,
            slave_last_rx(bond, slave) + 3 * delta_in_ticks + extra_ticks)) {

            slave->new_link = BOND_LINK_DOWN;
            commit++;
        }

        /*
         * Active slave is down if:
         * - more than 2*delta since transmitting OR
         * - (more than 2*delta since receive AND
         *    the bond has an IP address)
         */
        trans_start = dev_trans_start(slave->dev);
        if (bond_is_active_slave(slave) &&
            (!time_in_range(jiffies,
            trans_start - delta_in_ticks,
            trans_start + 2 * delta_in_ticks + extra_ticks) ||
             !time_in_range(jiffies,
            slave_last_rx(bond, slave) - delta_in_ticks,
            slave_last_rx(bond, slave) + 2 * delta_in_ticks + extra_ticks))) {

            slave->new_link = BOND_LINK_DOWN;
            commit++;
        }
    }

    return commit;
}

/*
 * Called to commit link state changes noted by inspection step of
 * active-backup mode ARP monitor.
 *
 * Called with RTNL and bond->lock for read.
 */
static void bond_ab_arp_commit(struct bonding *bond, int delta_in_ticks)
{
    struct slave *slave;
    int i;
    unsigned long trans_start;

    bond_for_each_slave(bond, slave, i) {
        switch (slave->new_link) {
        case BOND_LINK_NOCHANGE:
            continue;

        case BOND_LINK_UP:
            trans_start = dev_trans_start(slave->dev);
            if ((!bond->curr_active_slave &&
                 time_in_range(jiffies,
                       trans_start - delta_in_ticks,
                       trans_start + delta_in_ticks + delta_in_ticks / 2)) ||
                bond->curr_active_slave != slave) {
                slave->link = BOND_LINK_UP;
                if (bond->current_arp_slave) {
                    bond_set_slave_inactive_flags(
                        bond->current_arp_slave);
                    bond->current_arp_slave = NULL;
                }

                pr_info("%s: link status definitely up for interface %s.\n",
                    bond->dev->name, slave->dev->name);

                if (!bond->curr_active_slave ||
                    (slave == bond->primary_slave))
                    goto do_failover;

            }

            continue;

        case BOND_LINK_DOWN:
            if (slave->link_failure_count < UINT_MAX)
                slave->link_failure_count++;

            slave->link = BOND_LINK_DOWN;
            bond_set_slave_inactive_flags(slave);

            pr_info("%s: link status definitely down for interface %s, disabling it\n",
                bond->dev->name, slave->dev->name);

            if (slave == bond->curr_active_slave) {
                bond->current_arp_slave = NULL;
                goto do_failover;
            }

            continue;

        default:
            pr_err("%s: impossible: new_link %d on slave %s\n",
                   bond->dev->name, slave->new_link,
                   slave->dev->name);
            continue;
        }

do_failover:
        ASSERT_RTNL();
        block_netpoll_tx();
        write_lock_bh(&bond->curr_slave_lock);
        bond_select_active_slave(bond);
        write_unlock_bh(&bond->curr_slave_lock);
        unblock_netpoll_tx();
    }

    bond_set_carrier(bond);
}

/*
 * Send ARP probes for active-backup mode ARP monitor.
 *
 * Called with bond->lock held for read.
 */
static void bond_ab_arp_probe(struct bonding *bond)
{
    struct slave *slave;
    int i;

    read_lock(&bond->curr_slave_lock);

    if (bond->current_arp_slave && bond->curr_active_slave)
        pr_info("PROBE: c_arp %s && cas %s BAD\n",
            bond->current_arp_slave->dev->name,
            bond->curr_active_slave->dev->name);

    if (bond->curr_active_slave) {
        bond_arp_send_all(bond, bond->curr_active_slave);
        read_unlock(&bond->curr_slave_lock);
        return;
    }

    read_unlock(&bond->curr_slave_lock);

    /* if we don't have a curr_active_slave, search for the next available
     * backup slave from the current_arp_slave and make it the candidate
     * for becoming the curr_active_slave
     */

    if (!bond->current_arp_slave) {
        bond->current_arp_slave = bond->first_slave;
        if (!bond->current_arp_slave)
            return;
    }

    bond_set_slave_inactive_flags(bond->current_arp_slave);

    /* search for next candidate */
    bond_for_each_slave_from(bond, slave, i, bond->current_arp_slave->next) {
        if (IS_UP(slave->dev)) {
            slave->link = BOND_LINK_BACK;
            bond_set_slave_active_flags(slave);
            bond_arp_send_all(bond, slave);
            slave->jiffies = jiffies;
            bond->current_arp_slave = slave;
            break;
        }

        /* if the link state is up at this point, we
         * mark it down - this can happen if we have
         * simultaneous link failures and
         * reselect_active_interface doesn't make this
         * one the current slave so it is still marked
         * up when it is actually down
         */
        if (slave->link == BOND_LINK_UP) {
            slave->link = BOND_LINK_DOWN;
            if (slave->link_failure_count < UINT_MAX)
                slave->link_failure_count++;

            bond_set_slave_inactive_flags(slave);

            pr_info("%s: backup interface %s is now down.\n",
                bond->dev->name, slave->dev->name);
        }
    }
}

void bond_activebackup_arp_mon(struct work_struct *work)
{
    struct bonding *bond = container_of(work, struct bonding,
                        arp_work.work);
    bool should_notify_peers = false;
    int delta_in_ticks;

    read_lock(&bond->lock);

    delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);

    if (bond->slave_cnt == 0)
        goto re_arm;

    should_notify_peers = bond_should_notify_peers(bond);

    if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
        read_unlock(&bond->lock);

        /* Race avoidance with bond_close flush of workqueue */
        if (!rtnl_trylock()) {
            read_lock(&bond->lock);
            delta_in_ticks = 1;
            should_notify_peers = false;
            goto re_arm;
        }

        read_lock(&bond->lock);

        bond_ab_arp_commit(bond, delta_in_ticks);

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

    bond_ab_arp_probe(bond);

re_arm:
    if (bond->params.arp_interval)
        queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);

    read_unlock(&bond->lock);

    if (should_notify_peers) {
        if (!rtnl_trylock()) {
            read_lock(&bond->lock);
            bond->send_peer_notif++;
            read_unlock(&bond->lock);
            return;
        }
        call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);
        rtnl_unlock();
    }
}

/*-------------------------- netdev event handling --------------------------*/

/*
 * Change device name
 */
static int bond_event_changename(struct bonding *bond)
{
    bond_remove_proc_entry(bond);
    bond_create_proc_entry(bond);

    bond_debug_reregister(bond);

    return NOTIFY_DONE;
}

static int bond_master_netdev_event(unsigned long event,
                    struct net_device *bond_dev)
{
    struct bonding *event_bond = netdev_priv(bond_dev);

    switch (event) {
    case NETDEV_CHANGENAME:
        return bond_event_changename(event_bond);
    case NETDEV_UNREGISTER:
        bond_remove_proc_entry(event_bond);
        break;
    case NETDEV_REGISTER:
        bond_create_proc_entry(event_bond);
        break;
    default:
        break;
    }

    return NOTIFY_DONE;
}

static int bond_slave_netdev_event(unsigned long event,
                   struct net_device *slave_dev)
{
    struct net_device *bond_dev = slave_dev->master;
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave = NULL;

    switch (event) {
    case NETDEV_UNREGISTER:
        if (bond_dev) {
            if (bond->setup_by_slave)
                bond_release_and_destroy(bond_dev, slave_dev);
            else
                bond_release(bond_dev, slave_dev);
        }
        break;
    case NETDEV_UP:
    case NETDEV_CHANGE:
        slave = bond_get_slave_by_dev(bond, slave_dev);
        if (slave) {
            u32 old_speed = slave->speed;
            u8  old_duplex = slave->duplex;

            bond_update_speed_duplex(slave);

            if (bond->params.mode == BOND_MODE_8023AD) {
                if (old_speed != slave->speed)
                    bond_3ad_adapter_speed_changed(slave);
                if (old_duplex != slave->duplex)
                    bond_3ad_adapter_duplex_changed(slave);
            }
        }

        break;
    case NETDEV_DOWN:
        /*
         * ... Or is it this?
         */
        break;
    case NETDEV_CHANGEMTU:
        /*
         * TODO: Should slaves be allowed to
         * independently alter their MTU?  For
         * an active-backup bond, slaves need
         * not be the same type of device, so
         * MTUs may vary.  For other modes,
         * slaves arguably should have the
         * same MTUs. To do this, we'd need to
         * take over the slave's change_mtu
         * function for the duration of their
         * servitude.
         */
        break;
    case NETDEV_CHANGENAME:
        /*
         * TODO: handle changing the primary's name
         */
        break;
    case NETDEV_FEAT_CHANGE:
        bond_compute_features(bond);
        break;
    default:
        break;
    }

    return NOTIFY_DONE;
}

/*
 * bond_netdev_event: handle netdev notifier chain events.
 *
 * This function receives events for the netdev chain.  The caller (an
 * ioctl handler calling blocking_notifier_call_chain) holds the necessary
 * locks for us to safely manipulate the slave devices (RTNL lock,
 * dev_probe_lock).
 */
static int bond_netdev_event(struct notifier_block *this,
                 unsigned long event, void *ptr)
{
    struct net_device *event_dev = (struct net_device *)ptr;

    pr_debug("event_dev: %s, event: %lx\n",
         event_dev ? event_dev->name : "None",
         event);

    if (!(event_dev->priv_flags & IFF_BONDING))
        return NOTIFY_DONE;

    if (event_dev->flags & IFF_MASTER) {
        pr_debug("IFF_MASTER\n");
        return bond_master_netdev_event(event, event_dev);
    }

    if (event_dev->flags & IFF_SLAVE) {
        pr_debug("IFF_SLAVE\n");
        return bond_slave_netdev_event(event, event_dev);
    }

    return NOTIFY_DONE;
}

static struct notifier_block bond_netdev_notifier = {
    .notifier_call = bond_netdev_event,
};

/*---------------------------- Hashing Policies -----------------------------*/

/*
 * Hash for the output device based upon layer 2 data
 */
static int bond_xmit_hash_policy_l2(struct sk_buff *skb, int count)
{
    struct ethhdr *data = (struct ethhdr *)skb->data;

    if (skb_headlen(skb) >= offsetof(struct ethhdr, h_proto))
        return (data->h_dest[5] ^ data->h_source[5]) % count;

    return 0;
}

/*
 * Hash for the output device based upon layer 2 and layer 3 data. If
 * the packet is not IP, fall back on bond_xmit_hash_policy_l2()
 */
static int bond_xmit_hash_policy_l23(struct sk_buff *skb, int count)
{
    struct ethhdr *data = (struct ethhdr *)skb->data;
    struct iphdr *iph;
    struct ipv6hdr *ipv6h;
    u32 v6hash;
    __be32 *s, *d;

    if (skb->protocol == htons(ETH_P_IP) &&
        skb_network_header_len(skb) >= sizeof(*iph)) {
        iph = ip_hdr(skb);
        return ((ntohl(iph->saddr ^ iph->daddr) & 0xffff) ^
            (data->h_dest[5] ^ data->h_source[5])) % count;
    } else if (skb->protocol == htons(ETH_P_IPV6) &&
           skb_network_header_len(skb) >= sizeof(*ipv6h)) {
        ipv6h = ipv6_hdr(skb);
        s = &ipv6h->saddr.s6_addr32[0];
        d = &ipv6h->daddr.s6_addr32[0];
        v6hash = (s[1] ^ d[1]) ^ (s[2] ^ d[2]) ^ (s[3] ^ d[3]);
        v6hash ^= (v6hash >> 24) ^ (v6hash >> 16) ^ (v6hash >> 8);
        return (v6hash ^ data->h_dest[5] ^ data->h_source[5]) % count;
    }

    return bond_xmit_hash_policy_l2(skb, count);
}

/*
 * Hash for the output device based upon layer 3 and layer 4 data. If
 * the packet is a frag or not TCP or UDP, just use layer 3 data.  If it is
 * altogether not IP, fall back on bond_xmit_hash_policy_l2()
 */
static int bond_xmit_hash_policy_l34(struct sk_buff *skb, int count)
{
    u32 layer4_xor = 0;
    struct iphdr *iph;
    struct ipv6hdr *ipv6h;
    __be32 *s, *d;
    __be16 *layer4hdr;

    if (skb->protocol == htons(ETH_P_IP) &&
        skb_network_header_len(skb) >= sizeof(*iph)) {
        iph = ip_hdr(skb);
        if (!ip_is_fragment(iph) &&
            (iph->protocol == IPPROTO_TCP ||
             iph->protocol == IPPROTO_UDP) &&
            (skb_headlen(skb) - skb_network_offset(skb) >=
             iph->ihl * sizeof(u32) + sizeof(*layer4hdr) * 2)) {
            layer4hdr = (__be16 *)((u32 *)iph + iph->ihl);
            layer4_xor = ntohs(*layer4hdr ^ *(layer4hdr + 1));
        }
        return (layer4_xor ^
            ((ntohl(iph->saddr ^ iph->daddr)) & 0xffff)) % count;
    } else if (skb->protocol == htons(ETH_P_IPV6) &&
           skb_network_header_len(skb) >= sizeof(*ipv6h)) {
        ipv6h = ipv6_hdr(skb);
        if ((ipv6h->nexthdr == IPPROTO_TCP ||
             ipv6h->nexthdr == IPPROTO_UDP) &&
            (skb_headlen(skb) - skb_network_offset(skb) >=
             sizeof(*ipv6h) + sizeof(*layer4hdr) * 2)) {
            layer4hdr = (__be16 *)(ipv6h + 1);
            layer4_xor = ntohs(*layer4hdr ^ *(layer4hdr + 1));
        }
        s = &ipv6h->saddr.s6_addr32[0];
        d = &ipv6h->daddr.s6_addr32[0];
        layer4_xor ^= (s[1] ^ d[1]) ^ (s[2] ^ d[2]) ^ (s[3] ^ d[3]);
        layer4_xor ^= (layer4_xor >> 24) ^ (layer4_xor >> 16) ^
                   (layer4_xor >> 8);
        return layer4_xor % count;
    }

    return bond_xmit_hash_policy_l2(skb, count);
}

/*-------------------------- Device entry points ----------------------------*/

static void bond_work_init_all(struct bonding *bond)
{
    INIT_DELAYED_WORK(&bond->mcast_work,
              bond_resend_igmp_join_requests_delayed);
    INIT_DELAYED_WORK(&bond->alb_work, bond_alb_monitor);
    INIT_DELAYED_WORK(&bond->mii_work, bond_mii_monitor);
    if (bond->params.mode == BOND_MODE_ACTIVEBACKUP)
        INIT_DELAYED_WORK(&bond->arp_work, bond_activebackup_arp_mon);
    else
        INIT_DELAYED_WORK(&bond->arp_work, bond_loadbalance_arp_mon);
    INIT_DELAYED_WORK(&bond->ad_work, bond_3ad_state_machine_handler);
}

static void bond_work_cancel_all(struct bonding *bond)
{
    cancel_delayed_work_sync(&bond->mii_work);
    cancel_delayed_work_sync(&bond->arp_work);
    cancel_delayed_work_sync(&bond->alb_work);
    cancel_delayed_work_sync(&bond->ad_work);
    cancel_delayed_work_sync(&bond->mcast_work);
}

static int bond_open(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave;
    int i;

    /* reset slave->backup and slave->inactive */
    read_lock(&bond->lock);
    if (bond->slave_cnt > 0) {
        read_lock(&bond->curr_slave_lock);
        bond_for_each_slave(bond, slave, i) {
            if ((bond->params.mode == BOND_MODE_ACTIVEBACKUP)
                && (slave != bond->curr_active_slave)) {
                bond_set_slave_inactive_flags(slave);
            } else {
                bond_set_slave_active_flags(slave);
            }
        }
        read_unlock(&bond->curr_slave_lock);
    }
    read_unlock(&bond->lock);

    bond_work_init_all(bond);

    if (bond_is_lb(bond)) {
        /* bond_alb_initialize must be called before the timer
         * is started.
         */
        if (bond_alb_initialize(bond, (bond->params.mode == BOND_MODE_ALB)))
            return -ENOMEM;
        queue_delayed_work(bond->wq, &bond->alb_work, 0);
    }

    if (bond->params.miimon)  /* link check interval, in milliseconds. */
        queue_delayed_work(bond->wq, &bond->mii_work, 0);

    if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
        queue_delayed_work(bond->wq, &bond->arp_work, 0);
        if (bond->params.arp_validate)
            bond->recv_probe = bond_arp_rcv;
    }

    if (bond->params.mode == BOND_MODE_8023AD) {
        queue_delayed_work(bond->wq, &bond->ad_work, 0);
        /* register to receive LACPDUs */
        bond->recv_probe = bond_3ad_lacpdu_recv;
        bond_3ad_initiate_agg_selection(bond, 1);
    }

    return 0;
}

static int bond_close(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);

    write_lock_bh(&bond->lock);
    bond->send_peer_notif = 0;
    write_unlock_bh(&bond->lock);

    bond_work_cancel_all(bond);
    if (bond_is_lb(bond)) {
        /* Must be called only after all
         * slaves have been released
         */
        bond_alb_deinitialize(bond);
    }
    bond->recv_probe = NULL;

    return 0;
}

static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev,
                        struct rtnl_link_stats64 *stats)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct rtnl_link_stats64 temp;
    struct slave *slave;
    int i;

    memset(stats, 0, sizeof(*stats));

    read_lock_bh(&bond->lock);

    bond_for_each_slave(bond, slave, i) {
        const struct rtnl_link_stats64 *sstats =
            dev_get_stats(slave->dev, &temp);

        stats->rx_packets += sstats->rx_packets;
        stats->rx_bytes += sstats->rx_bytes;
        stats->rx_errors += sstats->rx_errors;
        stats->rx_dropped += sstats->rx_dropped;

        stats->tx_packets += sstats->tx_packets;
        stats->tx_bytes += sstats->tx_bytes;
        stats->tx_errors += sstats->tx_errors;
        stats->tx_dropped += sstats->tx_dropped;

        stats->multicast += sstats->multicast;
        stats->collisions += sstats->collisions;

        stats->rx_length_errors += sstats->rx_length_errors;
        stats->rx_over_errors += sstats->rx_over_errors;
        stats->rx_crc_errors += sstats->rx_crc_errors;
        stats->rx_frame_errors += sstats->rx_frame_errors;
        stats->rx_fifo_errors += sstats->rx_fifo_errors;
        stats->rx_missed_errors += sstats->rx_missed_errors;

        stats->tx_aborted_errors += sstats->tx_aborted_errors;
        stats->tx_carrier_errors += sstats->tx_carrier_errors;
        stats->tx_fifo_errors += sstats->tx_fifo_errors;
        stats->tx_heartbeat_errors += sstats->tx_heartbeat_errors;
        stats->tx_window_errors += sstats->tx_window_errors;
    }

    read_unlock_bh(&bond->lock);

    return stats;
}

static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd)
{
    struct net_device *slave_dev = NULL;
    struct ifbond k_binfo;
    struct ifbond __user *u_binfo = NULL;
    struct ifslave k_sinfo;
    struct ifslave __user *u_sinfo = NULL;
    struct mii_ioctl_data *mii = NULL;
    int res = 0;

    pr_debug("bond_ioctl: master=%s, cmd=%d\n", bond_dev->name, cmd);

    switch (cmd) {
    case SIOCGMIIPHY:
        mii = if_mii(ifr);
        if (!mii)
            return -EINVAL;

        mii->phy_id = 0;
        /* Fall Through */
    case SIOCGMIIREG:
        /*
         * We do this again just in case we were called by SIOCGMIIREG
         * instead of SIOCGMIIPHY.
         */
        mii = if_mii(ifr);
        if (!mii)
            return -EINVAL;


        if (mii->reg_num == 1) {
            struct bonding *bond = netdev_priv(bond_dev);
            mii->val_out = 0;
            read_lock(&bond->lock);
            read_lock(&bond->curr_slave_lock);
            if (netif_carrier_ok(bond->dev))
                mii->val_out = BMSR_LSTATUS;

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

        return 0;
    case BOND_INFO_QUERY_OLD:
    case SIOCBONDINFOQUERY:
        u_binfo = (struct ifbond __user *)ifr->ifr_data;

        if (copy_from_user(&k_binfo, u_binfo, sizeof(ifbond)))
            return -EFAULT;

        res = bond_info_query(bond_dev, &k_binfo);
        if (res == 0 &&
            copy_to_user(u_binfo, &k_binfo, sizeof(ifbond)))
            return -EFAULT;

        return res;
    case BOND_SLAVE_INFO_QUERY_OLD:
    case SIOCBONDSLAVEINFOQUERY:
        u_sinfo = (struct ifslave __user *)ifr->ifr_data;

        if (copy_from_user(&k_sinfo, u_sinfo, sizeof(ifslave)))
            return -EFAULT;

        res = bond_slave_info_query(bond_dev, &k_sinfo);
        if (res == 0 &&
            copy_to_user(u_sinfo, &k_sinfo, sizeof(ifslave)))
            return -EFAULT;

        return res;
    default:
        /* Go on */
        break;
    }

    if (!capable(CAP_NET_ADMIN))
        return -EPERM;

    slave_dev = dev_get_by_name(dev_net(bond_dev), ifr->ifr_slave);

    pr_debug("slave_dev=%p:\n", slave_dev);

    if (!slave_dev)
        res = -ENODEV;
    else {
        pr_debug("slave_dev->name=%s:\n", slave_dev->name);
        switch (cmd) {
        case BOND_ENSLAVE_OLD:
        case SIOCBONDENSLAVE:
            res = bond_enslave(bond_dev, slave_dev);
            break;
        case BOND_RELEASE_OLD:
        case SIOCBONDRELEASE:
            res = bond_release(bond_dev, slave_dev);
            break;
        case BOND_SETHWADDR_OLD:
        case SIOCBONDSETHWADDR:
            res = bond_sethwaddr(bond_dev, slave_dev);
            break;
        case BOND_CHANGE_ACTIVE_OLD:
        case SIOCBONDCHANGEACTIVE:
            res = bond_ioctl_change_active(bond_dev, slave_dev);
            break;
        default:
            res = -EOPNOTSUPP;
        }

        dev_put(slave_dev);
    }

    return res;
}

static bool bond_addr_in_mc_list(unsigned char *addr,
                 struct netdev_hw_addr_list *list,
                 int addrlen)
{
    struct netdev_hw_addr *ha;

    netdev_hw_addr_list_for_each(ha, list)
        if (!memcmp(ha->addr, addr, addrlen))
            return true;

    return false;
}

static void bond_change_rx_flags(struct net_device *bond_dev, int change)
{
    struct bonding *bond = netdev_priv(bond_dev);

    if (change & IFF_PROMISC)
        bond_set_promiscuity(bond,
                     bond_dev->flags & IFF_PROMISC ? 1 : -1);

    if (change & IFF_ALLMULTI)
        bond_set_allmulti(bond,
                  bond_dev->flags & IFF_ALLMULTI ? 1 : -1);
}

static void bond_set_multicast_list(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct netdev_hw_addr *ha;
    bool found;

    read_lock(&bond->lock);

    /* looking for addresses to add to slaves' mc list */
    netdev_for_each_mc_addr(ha, bond_dev) {
        found = bond_addr_in_mc_list(ha->addr, &bond->mc_list,
                         bond_dev->addr_len);
        if (!found)
            bond_mc_add(bond, ha->addr);
    }

    /* looking for addresses to delete from slaves' list */
    netdev_hw_addr_list_for_each(ha, &bond->mc_list) {
        found = bond_addr_in_mc_list(ha->addr, &bond_dev->mc,
                         bond_dev->addr_len);
        if (!found)
            bond_mc_del(bond, ha->addr);
    }

    /* save master's multicast list */
    __hw_addr_flush(&bond->mc_list);
    __hw_addr_add_multiple(&bond->mc_list, &bond_dev->mc,
                   bond_dev->addr_len, NETDEV_HW_ADDR_T_MULTICAST);

    read_unlock(&bond->lock);
}

static int bond_neigh_init(struct neighbour *n)
{
    struct bonding *bond = netdev_priv(n->dev);
    struct slave *slave = bond->first_slave;
    const struct net_device_ops *slave_ops;
    struct neigh_parms parms;
    int ret;

    if (!slave)
        return 0;

    slave_ops = slave->dev->netdev_ops;

    if (!slave_ops->ndo_neigh_setup)
        return 0;

    parms.neigh_setup = NULL;
    parms.neigh_cleanup = NULL;
    ret = slave_ops->ndo_neigh_setup(slave->dev, &parms);
    if (ret)
        return ret;

    /*
     * Assign slave's neigh_cleanup to neighbour in case cleanup is called
     * after the last slave has been detached.  Assumes that all slaves
     * utilize the same neigh_cleanup (true at this writing as only user
     * is ipoib).
     */
    n->parms->neigh_cleanup = parms.neigh_cleanup;

    if (!parms.neigh_setup)
        return 0;

    return parms.neigh_setup(n);
}

/*
 * The bonding ndo_neigh_setup is called at init time beofre any
 * slave exists. So we must declare proxy setup function which will
 * be used at run time to resolve the actual slave neigh param setup.
 */
static int bond_neigh_setup(struct net_device *dev,
                struct neigh_parms *parms)
{
    parms->neigh_setup   = bond_neigh_init;

    return 0;
}

/*
 * Change the MTU of all of a master's slaves to match the master
 */
static int bond_change_mtu(struct net_device *bond_dev, int new_mtu)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave, *stop_at;
    int res = 0;
    int i;

    pr_debug("bond=%p, name=%s, new_mtu=%d\n", bond,
         (bond_dev ? bond_dev->name : "None"), new_mtu);

    /* Can't hold bond->lock with bh disabled here since
     * some base drivers panic. On the other hand we can't
     * hold bond->lock without bh disabled because we'll
     * deadlock. The only solution is to rely on the fact
     * that we're under rtnl_lock here, and the slaves
     * list won't change. This doesn't solve the problem
     * of setting the slave's MTU while it is
     * transmitting, but the assumption is that the base
     * driver can handle that.
     *
     * TODO: figure out a way to safely iterate the slaves
     * list, but without holding a lock around the actual
     * call to the base driver.
     */

    bond_for_each_slave(bond, slave, i) {
        pr_debug("s %p s->p %p c_m %p\n",
             slave,
             slave->prev,
             slave->dev->netdev_ops->ndo_change_mtu);

        res = dev_set_mtu(slave->dev, new_mtu);

        if (res) {
            /* If we failed to set the slave's mtu to the new value
             * we must abort the operation even in ACTIVE_BACKUP
             * mode, because if we allow the backup slaves to have
             * different mtu values than the active slave we'll
             * need to change their mtu when doing a failover. That
             * means changing their mtu from timer context, which
             * is probably not a good idea.
             */
            pr_debug("err %d %s\n", res, slave->dev->name);
            goto unwind;
        }
    }

    bond_dev->mtu = new_mtu;

    return 0;

unwind:
    /* 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) {
        int tmp_res;

        tmp_res = dev_set_mtu(slave->dev, bond_dev->mtu);
        if (tmp_res) {
            pr_debug("unwind err %d dev %s\n",
                 tmp_res, slave->dev->name);
        }
    }

    return res;
}

/*
 * Change HW address
 *
 * Note that many devices must be down to change the HW address, and
 * downing the master releases all slaves.  We can make bonds full of
 * bonding devices to test this, however.
 */
static int bond_set_mac_address(struct net_device *bond_dev, void *addr)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct sockaddr *sa = addr, tmp_sa;
    struct slave *slave, *stop_at;
    int res = 0;
    int i;

    if (bond->params.mode == BOND_MODE_ALB)
        return bond_alb_set_mac_address(bond_dev, addr);


    pr_debug("bond=%p, name=%s\n",
         bond, bond_dev ? bond_dev->name : "None");

    /*
     * If fail_over_mac is set to active, do nothing and return
     * success.  Returning an error causes ifenslave to fail.
     */
    if (bond->params.fail_over_mac == BOND_FOM_ACTIVE)
        return 0;

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

    /* Can't hold bond->lock with bh disabled here since
     * some base drivers panic. On the other hand we can't
     * hold bond->lock without bh disabled because we'll
     * deadlock. The only solution is to rely on the fact
     * that we're under rtnl_lock here, and the slaves
     * list won't change. This doesn't solve the problem
     * of setting the slave's hw address while it is
     * transmitting, but the assumption is that the base
     * driver can handle that.
     *
     * TODO: figure out a way to safely iterate the slaves
     * list, but without holding a lock around the actual
     * call to the base driver.
     */

    bond_for_each_slave(bond, slave, i) {
        const struct net_device_ops *slave_ops = slave->dev->netdev_ops;
        pr_debug("slave %p %s\n", slave, slave->dev->name);

        if (slave_ops->ndo_set_mac_address == NULL) {
            res = -EOPNOTSUPP;
            pr_debug("EOPNOTSUPP %s\n", slave->dev->name);
            goto unwind;
        }

        res = dev_set_mac_address(slave->dev, addr);
        if (res) {
            /* TODO: consider downing the slave
             * and retry ?
             * User should expect communications
             * breakage anyway until ARP finish
             * updating, so...
             */
            pr_debug("err %d %s\n", res, slave->dev->name);
            goto unwind;
        }
    }

    /* success */
    memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
    return 0;

unwind:
    memcpy(tmp_sa.sa_data, bond_dev->dev_addr, bond_dev->addr_len);
    tmp_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) {
        int tmp_res;

        tmp_res = dev_set_mac_address(slave->dev, &tmp_sa);
        if (tmp_res) {
            pr_debug("unwind err %d dev %s\n",
                 tmp_res, slave->dev->name);
        }
    }

    return res;
}

static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave, *start_at;
    int i, slave_no, res = 1;
    struct iphdr *iph = ip_hdr(skb);

    /*
     * Start with the curr_active_slave that joined the bond as the
     * default for sending IGMP traffic.  For failover purposes one
     * needs to maintain some consistency for the interface that will
     * send the join/membership reports.  The curr_active_slave found
     * will send all of this type of traffic.
     */
    if ((iph->protocol == IPPROTO_IGMP) &&
        (skb->protocol == htons(ETH_P_IP))) {

        read_lock(&bond->curr_slave_lock);
        slave = bond->curr_active_slave;
        read_unlock(&bond->curr_slave_lock);

        if (!slave)
            goto out;
    } else {
        /*
         * Concurrent TX may collide on rr_tx_counter; we accept
         * that as being rare enough not to justify using an
         * atomic op here.
         */
        slave_no = bond->rr_tx_counter++ % bond->slave_cnt;

        bond_for_each_slave(bond, slave, i) {
            slave_no--;
            if (slave_no < 0)
                break;
        }
    }

    start_at = slave;
    bond_for_each_slave_from(bond, slave, i, start_at) {
        if (IS_UP(slave->dev) &&
            (slave->link == BOND_LINK_UP) &&
            bond_is_active_slave(slave)) {
            res = bond_dev_queue_xmit(bond, skb, slave->dev);
            break;
        }
    }

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

    return NETDEV_TX_OK;
}


/*
 * in active-backup mode, we know that bond->curr_active_slave is always valid if
 * the bond has a usable interface.
 */
static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    int res = 1;

    read_lock(&bond->curr_slave_lock);

    if (bond->curr_active_slave)
        res = bond_dev_queue_xmit(bond, skb,
            bond->curr_active_slave->dev);

    read_unlock(&bond->curr_slave_lock);

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

    return NETDEV_TX_OK;
}

/*
 * In bond_xmit_xor() , we determine the output device by using a pre-
 * determined xmit_hash_policy(), If the selected device is not enabled,
 * find the next active slave.
 */
static int bond_xmit_xor(struct sk_buff *skb, struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave, *start_at;
    int slave_no;
    int i;
    int res = 1;

    slave_no = bond->xmit_hash_policy(skb, bond->slave_cnt);

    bond_for_each_slave(bond, slave, i) {
        slave_no--;
        if (slave_no < 0)
            break;
    }

    start_at = slave;

    bond_for_each_slave_from(bond, slave, i, start_at) {
        if (IS_UP(slave->dev) &&
            (slave->link == BOND_LINK_UP) &&
            bond_is_active_slave(slave)) {
            res = bond_dev_queue_xmit(bond, skb, slave->dev);
            break;
        }
    }

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

    return NETDEV_TX_OK;
}

/*
 * in broadcast mode, we send everything to all usable interfaces.
 */
static int bond_xmit_broadcast(struct sk_buff *skb, struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct slave *slave, *start_at;
    struct net_device *tx_dev = NULL;
    int i;
    int res = 1;

    read_lock(&bond->curr_slave_lock);
    start_at = bond->curr_active_slave;
    read_unlock(&bond->curr_slave_lock);

    if (!start_at)
        goto out;

    bond_for_each_slave_from(bond, slave, i, start_at) {
        if (IS_UP(slave->dev) &&
            (slave->link == BOND_LINK_UP) &&
            bond_is_active_slave(slave)) {
            if (tx_dev) {
                struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
                if (!skb2) {
                    pr_err("%s: Error: bond_xmit_broadcast(): skb_clone() failed\n",
                           bond_dev->name);
                    continue;
                }

                res = bond_dev_queue_xmit(bond, skb2, tx_dev);
                if (res) {
                    kfree_skb(skb2);
                    continue;
                }
            }
            tx_dev = slave->dev;
        }
    }

    if (tx_dev)
        res = bond_dev_queue_xmit(bond, skb, tx_dev);

out:
    if (res)
        /* no suitable interface, frame not sent */
        kfree_skb(skb);

    /* frame sent to all suitable interfaces */
    return NETDEV_TX_OK;
}

/*------------------------- Device initialization ---------------------------*/

static void bond_set_xmit_hash_policy(struct bonding *bond)
{
    switch (bond->params.xmit_policy) {
    case BOND_XMIT_POLICY_LAYER23:
        bond->xmit_hash_policy = bond_xmit_hash_policy_l23;
        break;
    case BOND_XMIT_POLICY_LAYER34:
        bond->xmit_hash_policy = bond_xmit_hash_policy_l34;
        break;
    case BOND_XMIT_POLICY_LAYER2:
    default:
        bond->xmit_hash_policy = bond_xmit_hash_policy_l2;
        break;
    }
}

/*
 * Lookup the slave that corresponds to a qid
 */
static inline int bond_slave_override(struct bonding *bond,
                      struct sk_buff *skb)
{
    int i, res = 1;
    struct slave *slave = NULL;
    struct slave *check_slave;

    if (!skb->queue_mapping)
        return 1;

    /* Find out if any slaves have the same mapping as this skb. */
    bond_for_each_slave(bond, check_slave, i) {
        if (check_slave->queue_id == skb->queue_mapping) {
            slave = check_slave;
            break;
        }
    }

    /* If the slave isn't UP, use default transmit policy. */
    if (slave && slave->queue_id && IS_UP(slave->dev) &&
        (slave->link == BOND_LINK_UP)) {
        res = bond_dev_queue_xmit(bond, skb, slave->dev);
    }

    return res;
}


static u16 bond_select_queue(struct net_device *dev, struct sk_buff *skb)
{
    /*
     * This helper function exists to help dev_pick_tx get the correct
     * destination queue.  Using a helper function skips a call to
     * skb_tx_hash and will put the skbs in the queue we expect on their
     * way down to the bonding driver.
     */
    u16 txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0;

    /*
     * Save the original txq to restore before passing to the driver
     */
    qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping;

    if (unlikely(txq >= dev->real_num_tx_queues)) {
        do {
            txq -= dev->real_num_tx_queues;
        } while (txq >= dev->real_num_tx_queues);
    }
    return txq;
}

static netdev_tx_t __bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct bonding *bond = netdev_priv(dev);

    if (TX_QUEUE_OVERRIDE(bond->params.mode)) {
        if (!bond_slave_override(bond, skb))
            return NETDEV_TX_OK;
    }

    switch (bond->params.mode) {
    case BOND_MODE_ROUNDROBIN:
        return bond_xmit_roundrobin(skb, dev);
    case BOND_MODE_ACTIVEBACKUP:
        return bond_xmit_activebackup(skb, dev);
    case BOND_MODE_XOR:
        return bond_xmit_xor(skb, dev);
    case BOND_MODE_BROADCAST:
        return bond_xmit_broadcast(skb, dev);
    case BOND_MODE_8023AD:
        return bond_3ad_xmit_xor(skb, dev);
    case BOND_MODE_ALB:
    case BOND_MODE_TLB:
        return bond_alb_xmit(skb, dev);
    default:
        /* Should never happen, mode already checked */
        pr_err("%s: Error: Unknown bonding mode %d\n",
               dev->name, bond->params.mode);
        WARN_ON_ONCE(1);
        kfree_skb(skb);
        return NETDEV_TX_OK;
    }
}

static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct bonding *bond = netdev_priv(dev);
    netdev_tx_t ret = NETDEV_TX_OK;

    /*
     * If we risk deadlock from transmitting this in the
     * netpoll path, tell netpoll to queue the frame for later tx
     */
    if (is_netpoll_tx_blocked(dev))
        return NETDEV_TX_BUSY;

    read_lock(&bond->lock);

    if (bond->slave_cnt)
        ret = __bond_start_xmit(skb, dev);
    else
        kfree_skb(skb);

    read_unlock(&bond->lock);

    return ret;
}

/*
 * set bond mode specific net device operations
 */
void bond_set_mode_ops(struct bonding *bond, int mode)
{
    struct net_device *bond_dev = bond->dev;

    switch (mode) {
    case BOND_MODE_ROUNDROBIN:
        break;
    case BOND_MODE_ACTIVEBACKUP:
        break;
    case BOND_MODE_XOR:
        bond_set_xmit_hash_policy(bond);
        break;
    case BOND_MODE_BROADCAST:
        break;
    case BOND_MODE_8023AD:
        bond_set_xmit_hash_policy(bond);
        break;
    case BOND_MODE_ALB:
        /* FALLTHRU */
    case BOND_MODE_TLB:
        break;
    default:
        /* Should never happen, mode already checked */
        pr_err("%s: Error: Unknown bonding mode %d\n",
               bond_dev->name, mode);
        break;
    }
}

static void bond_ethtool_get_drvinfo(struct net_device *bond_dev,
                    struct ethtool_drvinfo *drvinfo)
{
    strncpy(drvinfo->driver, DRV_NAME, 32);
    strncpy(drvinfo->version, DRV_VERSION, 32);
    snprintf(drvinfo->fw_version, 32, "%d", BOND_ABI_VERSION);
}

static const struct ethtool_ops bond_ethtool_ops = {
    .get_drvinfo        = bond_ethtool_get_drvinfo,
    .get_link       = ethtool_op_get_link,
};

static const struct net_device_ops bond_netdev_ops = {
    .ndo_init       = bond_init,
    .ndo_uninit     = bond_uninit,
    .ndo_open       = bond_open,
    .ndo_stop       = bond_close,
    .ndo_start_xmit     = bond_start_xmit,
    .ndo_select_queue   = bond_select_queue,
    .ndo_get_stats64    = bond_get_stats,
    .ndo_do_ioctl       = bond_do_ioctl,
    .ndo_change_rx_flags    = bond_change_rx_flags,
    .ndo_set_rx_mode    = bond_set_multicast_list,
    .ndo_change_mtu     = bond_change_mtu,
    .ndo_set_mac_address    = bond_set_mac_address,
    .ndo_neigh_setup    = bond_neigh_setup,
    .ndo_vlan_rx_add_vid    = bond_vlan_rx_add_vid,
    .ndo_vlan_rx_kill_vid   = bond_vlan_rx_kill_vid,
#ifdef CONFIG_NET_POLL_CONTROLLER
    .ndo_netpoll_setup  = bond_netpoll_setup,
    .ndo_netpoll_cleanup    = bond_netpoll_cleanup,
    .ndo_poll_controller    = bond_poll_controller,
#endif
    .ndo_add_slave      = bond_enslave,
    .ndo_del_slave      = bond_release,
    .ndo_fix_features   = bond_fix_features,
};

static void bond_destructor(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    if (bond->wq)
        destroy_workqueue(bond->wq);
    free_netdev(bond_dev);
}

static void bond_setup(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);

    /* initialize rwlocks */
    rwlock_init(&bond->lock);
    rwlock_init(&bond->curr_slave_lock);

    bond->params = bonding_defaults;

    /* Initialize pointers */
    bond->dev = bond_dev;
    INIT_LIST_HEAD(&bond->vlan_list);

    /* Initialize the device entry points */
    ether_setup(bond_dev);
    bond_dev->netdev_ops = &bond_netdev_ops;
    bond_dev->ethtool_ops = &bond_ethtool_ops;
    bond_set_mode_ops(bond, bond->params.mode);

    bond_dev->destructor = bond_destructor;

    /* Initialize the device options */
    bond_dev->tx_queue_len = 0;
    bond_dev->flags |= IFF_MASTER|IFF_MULTICAST;
    bond_dev->priv_flags |= IFF_BONDING;
    bond_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);

    /* At first, we block adding VLANs. That's the only way to
     * prevent problems that occur when adding VLANs over an
     * empty bond. The block will be removed once non-challenged
     * slaves are enslaved.
     */
    bond_dev->features |= NETIF_F_VLAN_CHALLENGED;

    /* don't acquire bond device's netif_tx_lock when
     * transmitting */
    bond_dev->features |= NETIF_F_LLTX;

    /* By default, we declare the bond to be fully
     * VLAN hardware accelerated capable. Special
     * care is taken in the various xmit functions
     * when there are slaves that are not hw accel
     * capable
     */

    bond_dev->hw_features = BOND_VLAN_FEATURES |
                NETIF_F_HW_VLAN_TX |
                NETIF_F_HW_VLAN_RX |
                NETIF_F_HW_VLAN_FILTER;

    bond_dev->hw_features &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_HW_CSUM);
    bond_dev->features |= bond_dev->hw_features;
}

/*
* Destroy a bonding device.
* Must be under rtnl_lock when this function is called.
*/
static void bond_uninit(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct vlan_entry *vlan, *tmp;

    bond_netpoll_cleanup(bond_dev);

    /* Release the bonded slaves */
    bond_release_all(bond_dev);

    list_del(&bond->bond_list);

    bond_work_cancel_all(bond);

    bond_debug_unregister(bond);

    __hw_addr_flush(&bond->mc_list);

    list_for_each_entry_safe(vlan, tmp, &bond->vlan_list, vlan_list) {
        list_del(&vlan->vlan_list);
        kfree(vlan);
    }
}

/*------------------------- Module initialization ---------------------------*/

/*
 * Convert string input module parms.  Accept either the
 * number of the mode or its string name.  A bit complicated because
 * some mode names are substrings of other names, and calls from sysfs
 * may have whitespace in the name (trailing newlines, for example).
 */
int bond_parse_parm(const char *buf, const struct bond_parm_tbl *tbl)
{
    int modeint = -1, i, rv;
    char *p, modestr[BOND_MAX_MODENAME_LEN + 1] = { 0, };

    for (p = (char *)buf; *p; p++)
        if (!(isdigit(*p) || isspace(*p)))
            break;

    if (*p)
        rv = sscanf(buf, "%20s", modestr);
    else
        rv = sscanf(buf, "%d", &modeint);

    if (!rv)
        return -1;

    for (i = 0; tbl[i].modename; i++) {
        if (modeint == tbl[i].mode)
            return tbl[i].mode;
        if (strcmp(modestr, tbl[i].modename) == 0)
            return tbl[i].mode;
    }

    return -1;
}

static int bond_check_params(struct bond_params *params)
{
    int arp_validate_value, fail_over_mac_value, primary_reselect_value;

    /*
     * Convert string parameters.
     */
    if (mode) {
        bond_mode = bond_parse_parm(mode, bond_mode_tbl);
        if (bond_mode == -1) {
            pr_err("Error: Invalid bonding mode \"%s\"\n",
                   mode == NULL ? "NULL" : mode);
            return -EINVAL;
        }
    }

    if (xmit_hash_policy) {
        if ((bond_mode != BOND_MODE_XOR) &&
            (bond_mode != BOND_MODE_8023AD)) {
            pr_info("xmit_hash_policy param is irrelevant in mode %s\n",
                   bond_mode_name(bond_mode));
        } else {
            xmit_hashtype = bond_parse_parm(xmit_hash_policy,
                            xmit_hashtype_tbl);
            if (xmit_hashtype == -1) {
                pr_err("Error: Invalid xmit_hash_policy \"%s\"\n",
                       xmit_hash_policy == NULL ? "NULL" :
                       xmit_hash_policy);
                return -EINVAL;
            }
        }
    }

    if (lacp_rate) {
        if (bond_mode != BOND_MODE_8023AD) {
            pr_info("lacp_rate param is irrelevant in mode %s\n",
                bond_mode_name(bond_mode));
        } else {
            lacp_fast = bond_parse_parm(lacp_rate, bond_lacp_tbl);
            if (lacp_fast == -1) {
                pr_err("Error: Invalid lacp rate \"%s\"\n",
                       lacp_rate == NULL ? "NULL" : lacp_rate);
                return -EINVAL;
            }
        }
    }

    if (ad_select) {
        params->ad_select = bond_parse_parm(ad_select, ad_select_tbl);
        if (params->ad_select == -1) {
            pr_err("Error: Invalid ad_select \"%s\"\n",
                   ad_select == NULL ? "NULL" : ad_select);
            return -EINVAL;
        }

        if (bond_mode != BOND_MODE_8023AD) {
            pr_warning("ad_select param only affects 802.3ad mode\n");
        }
    } else {
        params->ad_select = BOND_AD_STABLE;
    }

    if (max_bonds < 0) {
        pr_warning("Warning: max_bonds (%d) not in range %d-%d, so it was reset to BOND_DEFAULT_MAX_BONDS (%d)\n",
               max_bonds, 0, INT_MAX, BOND_DEFAULT_MAX_BONDS);
        max_bonds = BOND_DEFAULT_MAX_BONDS;
    }

    if (miimon < 0) {
        pr_warning("Warning: miimon module parameter (%d), not in range 0-%d, so it was reset to %d\n",
               miimon, INT_MAX, BOND_LINK_MON_INTERV);
        miimon = BOND_LINK_MON_INTERV;
    }

    if (updelay < 0) {
        pr_warning("Warning: updelay module parameter (%d), not in range 0-%d, so it was reset to 0\n",
               updelay, INT_MAX);
        updelay = 0;
    }

    if (downdelay < 0) {
        pr_warning("Warning: downdelay module parameter (%d), not in range 0-%d, so it was reset to 0\n",
               downdelay, INT_MAX);
        downdelay = 0;
    }

    if ((use_carrier != 0) && (use_carrier != 1)) {
        pr_warning("Warning: use_carrier module parameter (%d), not of valid value (0/1), so it was set to 1\n",
               use_carrier);
        use_carrier = 1;
    }

    if (num_peer_notif < 0 || num_peer_notif > 255) {
        pr_warning("Warning: num_grat_arp/num_unsol_na (%d) not in range 0-255 so it was reset to 1\n",
               num_peer_notif);
        num_peer_notif = 1;
    }

    /* reset values for 802.3ad */
    if (bond_mode == BOND_MODE_8023AD) {
        if (!miimon) {
            pr_warning("Warning: miimon must be specified, otherwise bonding will not detect link failure, speed and duplex which are essential for 802.3ad operation\n");
            pr_warning("Forcing miimon to 100msec\n");
            miimon = 100;
        }
    }

    if (tx_queues < 1 || tx_queues > 255) {
        pr_warning("Warning: tx_queues (%d) should be between "
               "1 and 255, resetting to %d\n",
               tx_queues, BOND_DEFAULT_TX_QUEUES);
        tx_queues = BOND_DEFAULT_TX_QUEUES;
    }

    if ((all_slaves_active != 0) && (all_slaves_active != 1)) {
        pr_warning("Warning: all_slaves_active module parameter (%d), "
               "not of valid value (0/1), so it was set to "
               "0\n", all_slaves_active);
        all_slaves_active = 0;
    }

    if (resend_igmp < 0 || resend_igmp > 255) {
        pr_warning("Warning: resend_igmp (%d) should be between "
               "0 and 255, resetting to %d\n",
               resend_igmp, BOND_DEFAULT_RESEND_IGMP);
        resend_igmp = BOND_DEFAULT_RESEND_IGMP;
    }

    /* reset values for TLB/ALB */
    if ((bond_mode == BOND_MODE_TLB) ||
        (bond_mode == BOND_MODE_ALB)) {
        if (!miimon) {
            pr_warning("Warning: miimon must be specified, otherwise bonding will not detect link failure and link speed which are essential for TLB/ALB load balancing\n");
            pr_warning("Forcing miimon to 100msec\n");
            miimon = 100;
        }
    }

    if (bond_mode == BOND_MODE_ALB) {
        pr_notice("In ALB mode you might experience client disconnections upon reconnection of a link if the bonding module updelay parameter (%d msec) is incompatible with the forwarding delay time of the switch\n",
              updelay);
    }

    if (!miimon) {
        if (updelay || downdelay) {
            /* just warn the user the up/down delay will have
             * no effect since miimon is zero...
             */
            pr_warning("Warning: miimon module parameter not set and updelay (%d) or downdelay (%d) module parameter is set; updelay and downdelay have no effect unless miimon is set\n",
                   updelay, downdelay);
        }
    } else {
        /* don't allow arp monitoring */
        if (arp_interval) {
            pr_warning("Warning: miimon (%d) and arp_interval (%d) can't be used simultaneously, disabling ARP monitoring\n",
                   miimon, arp_interval);
            arp_interval = 0;
        }

        if ((updelay % miimon) != 0) {
            pr_warning("Warning: updelay (%d) is not a multiple of miimon (%d), updelay rounded to %d ms\n",
                   updelay, miimon,
                   (updelay / miimon) * miimon);
        }

        updelay /= miimon;

        if ((downdelay % miimon) != 0) {
            pr_warning("Warning: downdelay (%d) is not a multiple of miimon (%d), downdelay rounded to %d ms\n",
                   downdelay, miimon,
                   (downdelay / miimon) * miimon);
        }

        downdelay /= miimon;
    }

    if (arp_interval < 0) {
        pr_warning("Warning: arp_interval module parameter (%d) , not in range 0-%d, so it was reset to %d\n",
               arp_interval, INT_MAX, BOND_LINK_ARP_INTERV);
        arp_interval = BOND_LINK_ARP_INTERV;
    }

    for (arp_ip_count = 0;
         (arp_ip_count < BOND_MAX_ARP_TARGETS) && arp_ip_target[arp_ip_count];
         arp_ip_count++) {
        /* not complete check, but should be good enough to
           catch mistakes */
        __be32 ip = in_aton(arp_ip_target[arp_ip_count]);
        if (!isdigit(arp_ip_target[arp_ip_count][0]) ||
            ip == 0 || ip == htonl(INADDR_BROADCAST)) {
            pr_warning("Warning: bad arp_ip_target module parameter (%s), ARP monitoring will not be performed\n",
                   arp_ip_target[arp_ip_count]);
            arp_interval = 0;
        } else {
            arp_target[arp_ip_count] = ip;
        }
    }

    if (arp_interval && !arp_ip_count) {
        /* don't allow arping if no arp_ip_target given... */
        pr_warning("Warning: arp_interval module parameter (%d) specified without providing an arp_ip_target parameter, arp_interval was reset to 0\n",
               arp_interval);
        arp_interval = 0;
    }

    if (arp_validate) {
        if (bond_mode != BOND_MODE_ACTIVEBACKUP) {
            pr_err("arp_validate only supported in active-backup mode\n");
            return -EINVAL;
        }
        if (!arp_interval) {
            pr_err("arp_validate requires arp_interval\n");
            return -EINVAL;
        }

        arp_validate_value = bond_parse_parm(arp_validate,
                             arp_validate_tbl);
        if (arp_validate_value == -1) {
            pr_err("Error: invalid arp_validate \"%s\"\n",
                   arp_validate == NULL ? "NULL" : arp_validate);
            return -EINVAL;
        }
    } else
        arp_validate_value = 0;

    if (miimon) {
        pr_info("MII link monitoring set to %d ms\n", miimon);
    } else if (arp_interval) {
        int i;

        pr_info("ARP monitoring set to %d ms, validate %s, with %d target(s):",
            arp_interval,
            arp_validate_tbl[arp_validate_value].modename,
            arp_ip_count);

        for (i = 0; i < arp_ip_count; i++)
            pr_info(" %s", arp_ip_target[i]);

        pr_info("\n");

    } else if (max_bonds) {
        /* miimon and arp_interval not set, we need one so things
         * work as expected, see bonding.txt for details
         */
        pr_debug("Warning: either miimon or arp_interval and arp_ip_target module parameters must be specified, otherwise bonding will not detect link failures! see bonding.txt for details.\n");
    }

    if (primary && !USES_PRIMARY(bond_mode)) {
        /* currently, using a primary only makes sense
         * in active backup, TLB or ALB modes
         */
        pr_warning("Warning: %s primary device specified but has no effect in %s mode\n",
               primary, bond_mode_name(bond_mode));
        primary = NULL;
    }

    if (primary && primary_reselect) {
        primary_reselect_value = bond_parse_parm(primary_reselect,
                             pri_reselect_tbl);
        if (primary_reselect_value == -1) {
            pr_err("Error: Invalid primary_reselect \"%s\"\n",
                   primary_reselect ==
                    NULL ? "NULL" : primary_reselect);
            return -EINVAL;
        }
    } else {
        primary_reselect_value = BOND_PRI_RESELECT_ALWAYS;
    }

    if (fail_over_mac) {
        fail_over_mac_value = bond_parse_parm(fail_over_mac,
                              fail_over_mac_tbl);
        if (fail_over_mac_value == -1) {
            pr_err("Error: invalid fail_over_mac \"%s\"\n",
                   arp_validate == NULL ? "NULL" : arp_validate);
            return -EINVAL;
        }

        if (bond_mode != BOND_MODE_ACTIVEBACKUP)
            pr_warning("Warning: fail_over_mac only affects active-backup mode.\n");
    } else {
        fail_over_mac_value = BOND_FOM_NONE;
    }

    /* fill params struct with the proper values */
    params->mode = bond_mode;
    params->xmit_policy = xmit_hashtype;
    params->miimon = miimon;
    params->num_peer_notif = num_peer_notif;
    params->arp_interval = arp_interval;
    params->arp_validate = arp_validate_value;
    params->updelay = updelay;
    params->downdelay = downdelay;
    params->use_carrier = use_carrier;
    params->lacp_fast = lacp_fast;
    params->primary[0] = 0;
    params->primary_reselect = primary_reselect_value;
    params->fail_over_mac = fail_over_mac_value;
    params->tx_queues = tx_queues;
    params->all_slaves_active = all_slaves_active;
    params->resend_igmp = resend_igmp;
    params->min_links = min_links;

    if (primary) {
        strncpy(params->primary, primary, IFNAMSIZ);
        params->primary[IFNAMSIZ - 1] = 0;
    }

    memcpy(params->arp_targets, arp_target, sizeof(arp_target));

    return 0;
}

static struct lock_class_key bonding_netdev_xmit_lock_key;
static struct lock_class_key bonding_netdev_addr_lock_key;
static struct lock_class_key bonding_tx_busylock_key;

static void bond_set_lockdep_class_one(struct net_device *dev,
                       struct netdev_queue *txq,
                       void *_unused)
{
    lockdep_set_class(&txq->_xmit_lock,
              &bonding_netdev_xmit_lock_key);
}

static void bond_set_lockdep_class(struct net_device *dev)
{
    lockdep_set_class(&dev->addr_list_lock,
              &bonding_netdev_addr_lock_key);
    netdev_for_each_tx_queue(dev, bond_set_lockdep_class_one, NULL);
    dev->qdisc_tx_busylock = &bonding_tx_busylock_key;
}

/*
 * Called from registration process
 */
static int bond_init(struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct bond_net *bn = net_generic(dev_net(bond_dev), bond_net_id);
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

    pr_debug("Begin bond_init for %s\n", bond_dev->name);

    /*
     * Initialize locks that may be required during
     * en/deslave operations.  All of the bond_open work
     * (of which this is part) should really be moved to
     * a phase prior to dev_open
     */
    spin_lock_init(&(bond_info->tx_hashtbl_lock));
    spin_lock_init(&(bond_info->rx_hashtbl_lock));

    bond->wq = create_singlethread_workqueue(bond_dev->name);
    if (!bond->wq)
        return -ENOMEM;

    bond_set_lockdep_class(bond_dev);

    list_add_tail(&bond->bond_list, &bn->dev_list);

    bond_prepare_sysfs_group(bond);

    bond_debug_register(bond);

    __hw_addr_init(&bond->mc_list);
    return 0;
}

static int bond_validate(struct nlattr *tb[], struct nlattr *data[])
{
    if (tb[IFLA_ADDRESS]) {
        if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
            return -EINVAL;
        if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
            return -EADDRNOTAVAIL;
    }
    return 0;
}

static unsigned int bond_get_num_tx_queues(void)
{
    return tx_queues;
}

static struct rtnl_link_ops bond_link_ops __read_mostly = {
    .kind           = "bond",
    .priv_size      = sizeof(struct bonding),
    .setup          = bond_setup,
    .validate       = bond_validate,
    .get_num_tx_queues  = bond_get_num_tx_queues,
    .get_num_rx_queues  = bond_get_num_tx_queues, /* Use the same number
                                 as for TX queues */
};

/* Create a new bond based on the specified name and bonding parameters.
 * If name is NULL, obtain a suitable "bond%d" name for us.
 * Caller must NOT hold rtnl_lock; we need to release it here before we
 * set up our sysfs entries.
 */
int bond_create(struct net *net, const char *name)
{
    struct net_device *bond_dev;
    int res;

    rtnl_lock();

    bond_dev = alloc_netdev_mq(sizeof(struct bonding),
                   name ? name : "bond%d",
                   bond_setup, tx_queues);
    if (!bond_dev) {
        pr_err("%s: eek! can't alloc netdev!\n", name);
        rtnl_unlock();
        return -ENOMEM;
    }

    dev_net_set(bond_dev, net);
    bond_dev->rtnl_link_ops = &bond_link_ops;

    res = register_netdevice(bond_dev);

    netif_carrier_off(bond_dev);

    rtnl_unlock();
    if (res < 0)
        bond_destructor(bond_dev);
    return res;
}

static int __net_init bond_net_init(struct net *net)
{
    struct bond_net *bn = net_generic(net, bond_net_id);

    bn->net = net;
    INIT_LIST_HEAD(&bn->dev_list);

    bond_create_proc_dir(bn);
    bond_create_sysfs(bn);
    
    return 0;
}

static void __net_exit bond_net_exit(struct net *net)
{
    struct bond_net *bn = net_generic(net, bond_net_id);

    bond_destroy_sysfs(bn);
    bond_destroy_proc_dir(bn);
}

static struct pernet_operations bond_net_ops = {
    .init = bond_net_init,
    .exit = bond_net_exit,
    .id   = &bond_net_id,
    .size = sizeof(struct bond_net),
};

static int __init bonding_init(void)
{
    int i;
    int res;

    pr_info("%s", bond_version);

    res = bond_check_params(&bonding_defaults);
    if (res)
        goto out;

    res = register_pernet_subsys(&bond_net_ops);
    if (res)
        goto out;

    res = rtnl_link_register(&bond_link_ops);
    if (res)
        goto err_link;

    bond_create_debugfs();

    for (i = 0; i < max_bonds; i++) {
        res = bond_create(&init_net, NULL);
        if (res)
            goto err;
    }

    register_netdevice_notifier(&bond_netdev_notifier);
out:
    return res;
err:
    rtnl_link_unregister(&bond_link_ops);
err_link:
    unregister_pernet_subsys(&bond_net_ops);
    goto out;

}

static void __exit bonding_exit(void)
{
    unregister_netdevice_notifier(&bond_netdev_notifier);

    bond_destroy_debugfs();

    rtnl_link_unregister(&bond_link_ops);
    unregister_pernet_subsys(&bond_net_ops);

#ifdef CONFIG_NET_POLL_CONTROLLER
    /*
     * Make sure we don't have an imbalance on our netpoll blocking
     */
    WARN_ON(atomic_read(&netpoll_block_tx));
#endif
}

module_init(bonding_init);
module_exit(bonding_exit);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION(DRV_DESCRIPTION ", v" DRV_VERSION);
MODULE_AUTHOR("Thomas Davis, [email protected] and many others");
MODULE_ALIAS_RTNL_LINK("bond");