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Sourcecode: linux-fsl-imx51 version File versions  Download package

bond_main.c

/*
 * originally based on the dummy device.
 *
 * Copyright 1999, Thomas Davis, tadavis@lbl.gov.
 * 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.
 *
 */

#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/system.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/proc_fs.h>
#include <linux/seq_file.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 <net/route.h>
#include <net/net_namespace.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 num_grat_arp = 1;
static int num_unsol_na = 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 *lacp_rate;
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 struct bond_params bonding_defaults;

module_param(max_bonds, int, 0);
MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
module_param(num_grat_arp, int, 0644);
MODULE_PARM_DESC(num_grat_arp, "Number of gratuitous ARP packets to send on failover event");
module_param(num_unsol_na, int, 0644);
MODULE_PARM_DESC(num_unsol_na, "Number of unsolicited IPv6 Neighbor Advertisements packets to send on failover event");
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(lacp_rate, charp, 0);
MODULE_PARM_DESC(lacp_rate, "LACPDU tx rate to request from 802.3ad partner "
                      "(slow/fast)");
module_param(ad_select, charp, 0);
MODULE_PARM_DESC(ad_select, "803.ad aggregation selection logic: stable (0, default), bandwidth (1), count (2)");
module_param(xmit_hash_policy, charp, 0);
MODULE_PARM_DESC(xmit_hash_policy, "XOR hashing method: 0 for layer 2 (default)"
                           ", 1 for layer 3+4");
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: none (default), active, backup or 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.  none (default), active or follow");

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

static const char * const version =
      DRV_DESCRIPTION ": v" DRV_VERSION " (" DRV_RELDATE ")\n";

LIST_HEAD(bond_dev_list);

#ifdef CONFIG_PROC_FS
static struct proc_dir_entry *bond_proc_dir;
#endif

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},
};

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

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

static void bond_send_gratuitous_arp(struct bonding *bond);
static int bond_init(struct net_device *bond_dev);
static void bond_deinit(struct net_device *bond_dev);

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

static 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 -----------------------------------*/

/**
 * bond_add_vlan - add a new vlan id on bond
 * @bond: bond that got the notification
 * @vlan_id: the vlan id to add
 *
 * Returns -ENOMEM if allocation failed.
 */
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;
}

/**
 * bond_del_vlan - delete a vlan id from bond
 * @bond: bond that got the notification
 * @vlan_id: the vlan id to delete
 *
 * returns -ENODEV if @vlan_id was not found in @bond.
 */
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);

      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);

                  if (list_empty(&bond->vlan_list) &&
                      (bond->slave_cnt == 0)) {
                        /* Last VLAN removed and no slaves, so
                         * restore block on adding VLANs. This will
                         * be removed once new slaves that are not
                         * VLAN challenged will be added.
                         */
                        bond->dev->features |= NETIF_F_VLAN_CHALLENGED;
                  }

                  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);
      return res;
}

/**
 * bond_has_challenged_slaves
 * @bond: the bond we're working on
 *
 * Searches the slave list. Returns 1 if a vlan challenged slave
 * was found, 0 otherwise.
 *
 * Assumes bond->lock is held.
 */
static int bond_has_challenged_slaves(struct bonding *bond)
{
      struct slave *slave;
      int i;

      bond_for_each_slave(bond, slave, i) {
            if (slave->dev->features & NETIF_F_VLAN_CHALLENGED) {
                  pr_debug("found VLAN challenged slave - %s\n",
                        slave->dev->name);
                  return 1;
            }
      }

      pr_debug("no VLAN challenged slaves found\n");
      return 0;
}

/**
 * bond_next_vlan - safely skip to the next item in the vlans list.
 * @bond: the bond we're working on
 * @curr: item we're advancing from
 *
 * Returns %NULL if list is empty, bond->next_vlan if @curr is %NULL,
 * or @curr->next otherwise (even if it is @curr itself again).
 *
 * Caller must hold bond->lock
 */
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;
}

/**
 * bond_dev_queue_xmit - Prepare skb for xmit.
 *
 * @bond: bond device that got this skb for tx.
 * @skb: hw accel VLAN tagged skb to transmit
 * @slave_dev: slave that is supposed to xmit this skbuff
 *
 * When the bond gets an skb to transmit that is
 * already hardware accelerated VLAN tagged, and it
 * needs to relay this skb to a slave that is not
 * hw accel capable, the skb needs to be "unaccelerated",
 * i.e. strip the hwaccel tag and re-insert it as part
 * of the payload.
 */
int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb,
                  struct net_device *slave_dev)
{
      unsigned short uninitialized_var(vlan_id);

      if (!list_empty(&bond->vlan_list) &&
          !(slave_dev->features & NETIF_F_HW_VLAN_TX) &&
          vlan_get_tag(skb, &vlan_id) == 0) {
            skb->dev = slave_dev;
            skb = vlan_put_tag(skb, vlan_id);
            if (!skb) {
                  /* vlan_put_tag() frees the skb in case of error,
                   * so return success here so the calling functions
                   * won't attempt to free is again.
                   */
                  return 0;
            }
      } else {
            skb->dev = slave_dev;
      }

      skb->priority = 1;
      dev_queue_xmit(skb);

      return 0;
}

/*
 * In the following 3 functions, bond_vlan_rx_register(), 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.
*/

/**
 * bond_vlan_rx_register - Propagates registration to slaves
 * @bond_dev: bonding net device that got called
 * @grp: vlan group being registered
 */
static void bond_vlan_rx_register(struct net_device *bond_dev,
                          struct vlan_group *grp)
{
      struct bonding *bond = netdev_priv(bond_dev);
      struct slave *slave;
      int i;

      bond->vlgrp = grp;

      bond_for_each_slave(bond, slave, i) {
            struct net_device *slave_dev = slave->dev;
            const struct net_device_ops *slave_ops = slave_dev->netdev_ops;

            if ((slave_dev->features & NETIF_F_HW_VLAN_RX) &&
                slave_ops->ndo_vlan_rx_register) {
                  slave_ops->ndo_vlan_rx_register(slave_dev, grp);
            }
      }
}

/**
 * bond_vlan_rx_add_vid - Propagates adding an id to slaves
 * @bond_dev: bonding net device that got called
 * @vid: vlan id being added
 */
static void bond_vlan_rx_add_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) {
            struct net_device *slave_dev = slave->dev;
            const struct net_device_ops *slave_ops = slave_dev->netdev_ops;

            if ((slave_dev->features & NETIF_F_HW_VLAN_FILTER) &&
                slave_ops->ndo_vlan_rx_add_vid) {
                  slave_ops->ndo_vlan_rx_add_vid(slave_dev, vid);
            }
      }

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

/**
 * bond_vlan_rx_kill_vid - Propagates deleting an id to slaves
 * @bond_dev: bonding net device that got called
 * @vid: vlan id being removed
 */
static void bond_vlan_rx_kill_vid(struct net_device *bond_dev, uint16_t vid)
{
      struct bonding *bond = netdev_priv(bond_dev);
      struct slave *slave;
      struct net_device *vlan_dev;
      int i, res;

      bond_for_each_slave(bond, slave, i) {
            struct net_device *slave_dev = slave->dev;
            const struct net_device_ops *slave_ops = slave_dev->netdev_ops;

            if ((slave_dev->features & NETIF_F_HW_VLAN_FILTER) &&
                slave_ops->ndo_vlan_rx_kill_vid) {
                  /* Save and then restore vlan_dev in the grp array,
                   * since the slave's driver might clear it.
                   */
                  vlan_dev = vlan_group_get_device(bond->vlgrp, vid);
                  slave_ops->ndo_vlan_rx_kill_vid(slave_dev, vid);
                  vlan_group_set_device(bond->vlgrp, vid, vlan_dev);
            }
      }

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

static void bond_add_vlans_on_slave(struct bonding *bond, struct net_device *slave_dev)
{
      struct vlan_entry *vlan;
      const struct net_device_ops *slave_ops = slave_dev->netdev_ops;

      write_lock_bh(&bond->lock);

      if (list_empty(&bond->vlan_list))
            goto out;

      if ((slave_dev->features & NETIF_F_HW_VLAN_RX) &&
          slave_ops->ndo_vlan_rx_register)
            slave_ops->ndo_vlan_rx_register(slave_dev, bond->vlgrp);

      if (!(slave_dev->features & NETIF_F_HW_VLAN_FILTER) ||
          !(slave_ops->ndo_vlan_rx_add_vid))
            goto out;

      list_for_each_entry(vlan, &bond->vlan_list, vlan_list)
            slave_ops->ndo_vlan_rx_add_vid(slave_dev, vlan->vlan_id);

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

static void bond_del_vlans_from_slave(struct bonding *bond,
                              struct net_device *slave_dev)
{
      const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
      struct vlan_entry *vlan;
      struct net_device *vlan_dev;

      write_lock_bh(&bond->lock);

      if (list_empty(&bond->vlan_list))
            goto out;

      if (!(slave_dev->features & NETIF_F_HW_VLAN_FILTER) ||
          !(slave_ops->ndo_vlan_rx_kill_vid))
            goto unreg;

      list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
            /* Save and then restore vlan_dev in the grp array,
             * since the slave's driver might clear it.
             */
            vlan_dev = vlan_group_get_device(bond->vlgrp, vlan->vlan_id);
            slave_ops->ndo_vlan_rx_kill_vid(slave_dev, vlan->vlan_id);
            vlan_group_set_device(bond->vlgrp, vlan->vlan_id, vlan_dev);
      }

unreg:
      if ((slave_dev->features & NETIF_F_HW_VLAN_RX) &&
          slave_ops->ndo_vlan_rx_register)
            slave_ops->ndo_vlan_rx_register(slave_dev, NULL);

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

/*------------------------------- 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, fake speed and duplex to 100/Full
 * and return error.
 */
static int bond_update_speed_duplex(struct slave *slave)
{
      struct net_device *slave_dev = slave->dev;
      struct ethtool_cmd etool;
      int res;

      /* Fake speed and duplex */
      slave->speed = SPEED_100;
      slave->duplex = DUPLEX_FULL;

      if (!slave_dev->ethtool_ops || !slave_dev->ethtool_ops->get_settings)
            return -1;

      res = slave_dev->ethtool_ops->get_settings(slave_dev, &etool);
      if (res < 0)
            return -1;

      switch (etool.speed) {
      case SPEED_10:
      case SPEED_100:
      case SPEED_1000:
      case SPEED_10000:
            break;
      default:
            return -1;
      }

      switch (etool.duplex) {
      case DUPLEX_FULL:
      case DUPLEX_HALF:
            break;
      default:
            return -1;
      }

      slave->speed = etool.speed;
      slave->duplex = etool.duplex;

      return 0;
}

/*
 * 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;
      static int (*ioctl)(struct net_device *, struct ifreq *, int);
      struct ifreq ifr;
      struct mii_ioctl_data *mii;

      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 ------------------------------*/

/*
 * Returns 0 if dmi1 and dmi2 are the same, non-0 otherwise
 */
static inline int bond_is_dmi_same(const struct dev_mc_list *dmi1,
                           const struct dev_mc_list *dmi2)
{
      return memcmp(dmi1->dmi_addr, dmi2->dmi_addr, dmi1->dmi_addrlen) == 0 &&
                  dmi1->dmi_addrlen == dmi2->dmi_addrlen;
}

/*
 * returns dmi entry if found, NULL otherwise
 */
static struct dev_mc_list *bond_mc_list_find_dmi(struct dev_mc_list *dmi,
                                     struct dev_mc_list *mc_list)
{
      struct dev_mc_list *idmi;

      for (idmi = mc_list; idmi; idmi = idmi->next) {
            if (bond_is_dmi_same(dmi, idmi))
                  return idmi;
      }

      return NULL;
}

/*
 * 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, int alen)
{
      if (USES_PRIMARY(bond->params.mode)) {
            /* write lock already acquired */
            if (bond->curr_active_slave)
                  dev_mc_add(bond->curr_active_slave->dev, addr, alen, 0);
      } else {
            struct slave *slave;
            int i;

            bond_for_each_slave(bond, slave, i)
                  dev_mc_add(slave->dev, addr, alen, 0);
      }
}

/*
 * Remove a multicast address from slave
 * according to mode
 */
static void bond_mc_delete(struct bonding *bond, void *addr, int alen)
{
      if (USES_PRIMARY(bond->params.mode)) {
            /* write lock already acquired */
            if (bond->curr_active_slave)
                  dev_mc_delete(bond->curr_active_slave->dev, addr,
                              alen, 0);
      } else {
            struct slave *slave;
            int i;
            bond_for_each_slave(bond, slave, i) {
                  dev_mc_delete(slave->dev, addr, alen, 0);
            }
      }
}


/*
 * 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 in_device *in_dev;
      struct ip_mc_list *im;

      rcu_read_lock();
      in_dev = __in_dev_get_rcu(bond->dev);
      if (in_dev) {
            for (im = in_dev->mc_list; im; im = im->next)
                  ip_mc_rejoin_group(im);
      }

      rcu_read_unlock();
}

/*
 * Totally destroys the mc_list in bond
 */
static void bond_mc_list_destroy(struct bonding *bond)
{
      struct dev_mc_list *dmi;

      dmi = bond->mc_list;
      while (dmi) {
            bond->mc_list = dmi->next;
            kfree(dmi);
            dmi = bond->mc_list;
      }

      bond->mc_list = NULL;
}

/*
 * Copy all the Multicast addresses from src to the bonding device dst
 */
static int bond_mc_list_copy(struct dev_mc_list *mc_list, struct bonding *bond,
                       gfp_t gfp_flag)
{
      struct dev_mc_list *dmi, *new_dmi;

      for (dmi = mc_list; dmi; dmi = dmi->next) {
            new_dmi = kmalloc(sizeof(struct dev_mc_list), gfp_flag);

            if (!new_dmi) {
                  /* FIXME: Potential memory leak !!! */
                  return -ENOMEM;
            }

            new_dmi->next = bond->mc_list;
            bond->mc_list = new_dmi;
            new_dmi->dmi_addrlen = dmi->dmi_addrlen;
            memcpy(new_dmi->dmi_addr, dmi->dmi_addr, dmi->dmi_addrlen);
            new_dmi->dmi_users = dmi->dmi_users;
            new_dmi->dmi_gusers = dmi->dmi_gusers;
      }

      return 0;
}

/*
 * 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 dev_mc_list *dmi;

      for (dmi = bond_dev->mc_list; dmi; dmi = dmi->next)
            dev_mc_delete(slave_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);

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

            dev_mc_delete(slave_dev, lacpdu_multicast, ETH_ALEN, 0);
      }
}

/*--------------------------- 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 dev_mc_list *dmi;

      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);

            for (dmi = bond->dev->mc_list; dmi; dmi = dmi->next)
                  dev_mc_delete(old_active->dev, dmi->dmi_addr,
                              dmi->dmi_addrlen, 0);
      }

      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);

            for (dmi = bond->dev->mc_list; dmi; dmi = dmi->next)
                  dev_mc_add(new_active->dev, dmi->dmi_addr,
                           dmi->dmi_addrlen, 0);
            bond_resend_igmp_join_requests(bond);
      }
}

/*
 * 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);
            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(DRV_NAME
                         ": %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(DRV_NAME
                         ": %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(DRV_NAME
                   ": %s: bond_do_fail_over_mac impossible: bad policy %d\n",
                   bond->dev->name, bond->params.fail_over_mac);
            break;
      }

}


/**
 * find_best_interface - select the best available slave to be the active one
 * @bond: our bonding struct
 *
 * Warning: Caller must hold curr_slave_lock for writing.
 */
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 = old_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 */
      }

      /*
       * first try the primary link; if arping, a link must tx/rx
       * traffic before it can be considered the curr_active_slave.
       * also, we would skip slaves between the curr_active_slave
       * and primary_slave that may be up and able to arp
       */
      if ((bond->primary_slave) &&
          (!bond->params.arp_interval) &&
          (IS_UP(bond->primary_slave->dev))) {
            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 (IS_UP(new_active->dev)) {
                  if (new_active->link == BOND_LINK_UP) {
                        return new_active;
                  } else if (new_active->link == BOND_LINK_BACK) {
                        /* link up, but waiting for stabilization */
                        if (new_active->delay < mintime) {
                              mintime = new_active->delay;
                              bestslave = new_active;
                        }
                  }
            }
      }

      return bestslave;
}

/**
 * change_active_interface - change the active slave into the specified one
 * @bond: our bonding struct
 * @new: the new slave to make the active one
 *
 * Set the new slave to the bond's settings and unset them on the old
 * curr_active_slave.
 * Setting include flags, mc-list, promiscuity, allmulti, etc.
 *
 * If @new's link state is %BOND_LINK_BACK we'll set it to %BOND_LINK_UP,
 * because it is apparently the best available slave we have, even though its
 * updelay hasn't timed out yet.
 *
 * If new_active is not NULL, caller must hold bond->lock for read and
 * curr_slave_lock for write_bh.
 */
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(DRV_NAME
                               ": %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(DRV_NAME
                               ": %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) {
                  bond_set_slave_active_flags(new_active);

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

                  bond->send_grat_arp = bond->params.num_grat_arp;
                  bond_send_gratuitous_arp(bond);

                  bond->send_unsol_na = bond->params.num_unsol_na;
                  bond_send_unsolicited_na(bond);

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

                  netdev_bonding_change(bond->dev);

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

/**
 * bond_select_active_slave - select a new active slave, if needed
 * @bond: our bonding struct
 *
 * This functions should be called when one of the following occurs:
 * - The old curr_active_slave has been released or lost its link.
 * - The primary_slave has got its link back.
 * - A slave has got its link back and there's no old curr_active_slave.
 *
 * Caller must hold bond->lock for read and curr_slave_lock for write_bh.
 */
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(DRV_NAME
                         ": %s: first active interface up!\n",
                         bond->dev->name);
            } else {
                  pr_info(DRV_NAME ": %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--;
}

/*---------------------------------- 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;
}

#define BOND_VLAN_FEATURES \
      (NETIF_F_VLAN_CHALLENGED | NETIF_F_HW_VLAN_RX | NETIF_F_HW_VLAN_TX | \
       NETIF_F_HW_VLAN_FILTER)

/*
 * Compute the common dev->feature set available to all slaves.  Some
 * feature bits are managed elsewhere, so preserve those feature bits
 * on the master device.
 */
static int bond_compute_features(struct bonding *bond)
{
      struct slave *slave;
      struct net_device *bond_dev = bond->dev;
      unsigned long features = bond_dev->features;
      unsigned short max_hard_header_len = max((u16)ETH_HLEN,
                                    bond_dev->hard_header_len);
      int i;

      features &= ~(NETIF_F_ALL_CSUM | BOND_VLAN_FEATURES);
      features |=  NETIF_F_GSO_MASK | NETIF_F_NO_CSUM;

      if (!bond->first_slave)
            goto done;

      features &= ~NETIF_F_ONE_FOR_ALL;

      bond_for_each_slave(bond, slave, i) {
            features = netdev_increment_features(features,
                                         slave->dev->features,
                                         NETIF_F_ONE_FOR_ALL);
            if (slave->dev->hard_header_len > max_hard_header_len)
                  max_hard_header_len = slave->dev->hard_header_len;
      }

done:
      features |= (bond_dev->features & BOND_VLAN_FEATURES);
      bond_dev->features = netdev_fix_features(features, NULL);
      bond_dev->hard_header_len = max_hard_header_len;

      return 0;
}

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;
}

/* 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 dev_mc_list *dmi;
      struct sockaddr addr;
      int link_reporting;
      int old_features = bond_dev->features;
      int res = 0;

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

      /* bond must be initialized by bond_open() before enslaving */
      if (!(bond_dev->flags & IFF_UP)) {
            pr_warning(DRV_NAME
                  " %s: master_dev is not up in bond_enslave\n",
                  bond_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 (!list_empty(&bond->vlan_list)) {
                  pr_err(DRV_NAME
                         ": %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(DRV_NAME
                         ": %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);
                  bond_dev->features |= NETIF_F_VLAN_CHALLENGED;
            }
      } else {
            pr_debug("%s: ! NETIF_F_VLAN_CHALLENGED\n", slave_dev->name);
            if (bond->slave_cnt == 0) {
                  /* First slave, and it is not VLAN challenged,
                   * so remove the block of adding VLANs over the bond.
                   */
                  bond_dev->features &= ~NETIF_F_VLAN_CHALLENGED;
            }
      }

      /*
       * 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(DRV_NAME ": %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) {
                  dev_close(bond_dev);
                  pr_debug("%s: change device type from %d to %d\n",
                        bond_dev->name, bond_dev->type, slave_dev->type);
                  if (slave_dev->type != ARPHRD_ETHER)
                        bond_setup_by_slave(bond_dev, slave_dev);
                  else
                        ether_setup(bond_dev);
                  dev_open(bond_dev);
            }
      } else if (bond_dev->type != slave_dev->type) {
            pr_err(DRV_NAME ": %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(DRV_NAME
                         ": %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(DRV_NAME
                        ": %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;
            }
      }

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

      /* save slave's original flags before calling
       * netdev_set_master and dev_open
       */
      new_slave->original_flags = slave_dev->flags;

      /*
       * 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_free;
            }
      }

      res = netdev_set_master(slave_dev, bond_dev);
      if (res) {
            pr_debug("Error %d calling netdev_set_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->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 */
            for (dmi = bond_dev->mc_list; dmi; dmi = dmi->next)
                  dev_mc_add(slave_dev, dmi->dmi_addr,
                           dmi->dmi_addrlen, 0);
            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, ETH_ALEN, 0);
      }

      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;

      bond_compute_features(bond);

      write_unlock_bh(&bond->lock);

      read_lock(&bond->lock);

      new_slave->last_arp_rx = jiffies;

      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(DRV_NAME
                         ": %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(DRV_NAME
                         ": %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 ||
          (bond_check_dev_link(bond, slave_dev, 0) == BMSR_LSTATUS)) {
            if (bond->params.updelay) {
                  pr_debug("Initial state of slave_dev is "
                        "BOND_LINK_BACK\n");
                  new_slave->link  = BOND_LINK_BACK;
                  new_slave->delay = bond->params.updelay;
            } else {
                  pr_debug("Initial state of slave_dev is "
                        "BOND_LINK_UP\n");
                  new_slave->link  = BOND_LINK_UP;
            }
            new_slave->jiffies = jiffies;
      } else {
            pr_debug("Initial state of slave_dev is "
                  "BOND_LINK_DOWN\n");
            new_slave->link  = BOND_LINK_DOWN;
      }

      if (bond_update_speed_duplex(new_slave) &&
          (new_slave->link != BOND_LINK_DOWN)) {
            pr_warning(DRV_NAME
                   ": %s: Warning: failed to get speed and duplex from %s, "
                   "assumed to be 100Mb/sec and Full.\n",
                   bond_dev->name, new_slave->dev->name);

            if (bond->params.mode == BOND_MODE_8023AD) {
                  pr_warning(DRV_NAME
                         ": %s: Warning: Operation of 802.3ad mode requires ETHTOOL "
                         "support in base driver for proper aggregator "
                         "selection.\n", bond_dev->name);
            }
      }

      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;
      }

      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,
                                  bond->params.lacp_fast);
            } 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:
            new_slave->state = BOND_STATE_ACTIVE;
            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 */
            new_slave->state = BOND_STATE_ACTIVE;

            /* 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);

      read_unlock(&bond->lock);

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

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

      /* enslave is successful */
      return 0;

/* Undo stages on error */
err_close:
      dev_close(slave_dev);

err_unset_master:
      netdev_set_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_free:
      kfree(new_slave);

err_undo_flags:
      bond_dev->features = old_features;

      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;
      int mac_addr_differ;

      /* 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(DRV_NAME
                   ": %s: Error: cannot release %s.\n",
                   bond_dev->name, slave_dev->name);
            return -EINVAL;
      }

      write_lock_bh(&bond->lock);

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

      if (!bond->params.fail_over_mac) {
            mac_addr_differ = memcmp(bond_dev->dev_addr, slave->perm_hwaddr,
                               ETH_ALEN);
            if (!mac_addr_differ && (bond->slave_cnt > 1))
                  pr_warning(DRV_NAME
                         ": %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(DRV_NAME
             ": %s: releasing %s interface %s\n",
             bond_dev->name,
             (slave->state == BOND_STATE_ACTIVE)
             ? "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);

      bond_compute_features(bond);

      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 (list_empty(&bond->vlan_list)) {
                  bond_dev->features |= NETIF_F_VLAN_CHALLENGED;
            } else {
                  pr_warning(DRV_NAME
                         ": %s: Warning: clearing HW address of %s while it "
                         "still has VLANs.\n",
                         bond_dev->name, bond_dev->name);
                  pr_warning(DRV_NAME
                         ": %s: When re-adding slaves, make sure the bond's "
                         "HW address matches its VLANs'.\n",
                         bond_dev->name);
            }
      } else if ((bond_dev->features & NETIF_F_VLAN_CHALLENGED) &&
               !bond_has_challenged_slaves(bond)) {
            pr_info(DRV_NAME
                   ": %s: last VLAN challenged slave %s "
                   "left bond %s. VLAN blocking is removed\n",
                   bond_dev->name, slave_dev->name, bond_dev->name);
            bond_dev->features &= ~NETIF_F_VLAN_CHALLENGED;
      }

      write_unlock_bh(&bond->lock);

      /* 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_master(slave_dev, NULL);

      /* 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);
      }

      slave_dev->priv_flags &= ~(IFF_MASTER_8023AD | IFF_MASTER_ALB |
                           IFF_SLAVE_INACTIVE | IFF_BONDING |
                           IFF_SLAVE_NEEDARP);

      kfree(slave);

      return 0;  /* deletion OK */
}

/*
* 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);

      bond_deinit(bond_dev);
      bond_destroy_sysfs_entry(bond);

      if (bond->wq)
            destroy_workqueue(bond->wq);

      netif_addr_lock_bh(bond_dev);
      bond_mc_list_destroy(bond);
      netif_addr_unlock_bh(bond_dev);
}

/*
* First release a slave and than destroy the bond if no more slaves are left.
* Must be under rtnl_lock when this function is called.
*/
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)) {
            pr_info(DRV_NAME ": %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);

            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_compute_features(bond);

            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_master(slave_dev, NULL);

            /* 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);
            }

            slave_dev->priv_flags &= ~(IFF_MASTER_8023AD | IFF_MASTER_ALB |
                                 IFF_SLAVE_INACTIVE);

            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 (list_empty(&bond->vlan_list))
            bond_dev->features |= NETIF_F_VLAN_CHALLENGED;
      else {
            pr_warning(DRV_NAME
                   ": %s: Warning: clearing HW address of %s while it "
                   "still has VLANs.\n",
                   bond_dev->name, bond_dev->name);
            pr_warning(DRV_NAME
                   ": %s: When re-adding slaves, make sure the bond's "
                   "HW address matches its VLANs'.\n",
                   bond_dev->name);
      }

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

out:
      write_unlock_bh(&bond->lock);

      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)) {
            write_lock_bh(&bond->curr_slave_lock);
            bond_change_active_slave(bond, new_active);
            write_unlock_bh(&bond->curr_slave_lock);
      } 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 = slave->state;
                  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(DRV_NAME
                               ": %s: link status down for %s"
                               "interface %s, disabling it in %d ms.\n",
                               bond->dev->name,
                               (bond->params.mode ==
                              BOND_MODE_ACTIVEBACKUP) ?
                               ((slave->state == BOND_STATE_ACTIVE) ?
                              "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(DRV_NAME
                               ": %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(DRV_NAME
                               ": %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(DRV_NAME
                               ": %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 */
                        slave->state = BOND_STATE_BACKUP;
                  } else if (bond->params.mode != BOND_MODE_ACTIVEBACKUP) {
                        /* make it immediately active */
                        slave->state = BOND_STATE_ACTIVE;
                  } else if (slave != bond->primary_slave) {
                        /* prevent it from being the active one */
                        slave->state = BOND_STATE_BACKUP;
                  }

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

                  /* 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(DRV_NAME
                         ": %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(DRV_NAME
                         ": %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();
            write_lock_bh(&bond->curr_slave_lock);
            bond_select_active_slave(bond);
            write_unlock_bh(&bond->curr_slave_lock);
      }

      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);

      read_lock(&bond->lock);
      if (bond->kill_timers)
            goto out;

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

      if (bond->send_grat_arp) {
            read_lock(&bond->curr_slave_lock);
            bond_send_gratuitous_arp(bond);
            read_unlock(&bond->curr_slave_lock);
      }

      if (bond->send_unsol_na) {
            read_lock(&bond->curr_slave_lock);
            bond_send_unsolicited_na(bond);
            read_unlock(&bond->curr_slave_lock);
      }

      if (bond_miimon_inspect(bond)) {
            read_unlock(&bond->lock);
            rtnl_lock();
            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,
                           msecs_to_jiffies(bond->params.miimon));
out:
      read_unlock(&bond->lock);
}

static __be32 bond_glean_dev_ip(struct net_device *dev)
{
      struct in_device *idev;
      struct in_ifaddr *ifa;
      __be32 addr = 0;

      if (!dev)
            return 0;

      rcu_read_lock();
      idev = __in_dev_get_rcu(dev);
      if (!idev)
            goto out;

      ifa = idev->ifa_list;
      if (!ifa)
            goto out;

      addr = ifa->ifa_local;
out:
      rcu_read_unlock();
      return addr;
}

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

      if (ip == bond->master_ip)
            return 1;

      list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
            if (ip == vlan->vlan_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(DRV_NAME ": ARP packet allocation failed\n");
            return;
      }
      if (vlan_id) {
            skb = vlan_put_tag(skb, vlan_id);
            if (!skb) {
                  pr_err(DRV_NAME ": 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, rv;
      __be32 *targets = bond->params.arp_targets;
      struct vlan_entry *vlan;
      struct net_device *vlan_dev;
      struct flowi fl;
      struct rtable *rt;

      for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
            if (!targets[i])
                  break;
            pr_debug("basa: target %x\n", targets[i]);
            if (list_empty(&bond->vlan_list)) {
                  pr_debug("basa: empty vlan: arp_send\n");
                  bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                              bond->master_ip, 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.
             */
            memset(&fl, 0, sizeof(fl));
            fl.fl4_dst = targets[i];
            fl.fl4_tos = RTO_ONLINK;

            rv = ip_route_output_key(&init_net, &rt, &fl);
            if (rv) {
                  if (net_ratelimit()) {
                        pr_warning(DRV_NAME
                       ": %s: no route to arp_ip_target %pI4\n",
                               bond->dev->name, &fl.fl4_dst);
                  }
                  continue;
            }

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

            vlan_id = 0;
            list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                  vlan_dev = vlan_group_get_device(bond->vlgrp, vlan->vlan_id);
                  if (vlan_dev == rt->u.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) {
                  ip_rt_put(rt);
                  bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                              vlan->vlan_ip, vlan_id);
                  continue;
            }

            if (net_ratelimit()) {
                  pr_warning(DRV_NAME
             ": %s: no path to arp_ip_target %pI4 via rt.dev %s\n",
                         bond->dev->name, &fl.fl4_dst,
                         rt->u.dst.dev ? rt->u.dst.dev->name : "NULL");
            }
            ip_rt_put(rt);
      }
}

/*
 * Kick out a gratuitous ARP for an IP on the bonding master plus one
 * for each VLAN above us.
 *
 * Caller must hold curr_slave_lock for read or better
 */
static void bond_send_gratuitous_arp(struct bonding *bond)
{
      struct slave *slave = bond->curr_active_slave;
      struct vlan_entry *vlan;
      struct net_device *vlan_dev;

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

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

      bond->send_grat_arp--;

      if (bond->master_ip) {
            bond_arp_send(slave->dev, ARPOP_REPLY, bond->master_ip,
                        bond->master_ip, 0);
      }

      list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
            vlan_dev = vlan_group_get_device(bond->vlgrp, vlan->vlan_id);
            if (vlan->vlan_ip) {
                  bond_arp_send(slave->dev, ARPOP_REPLY, vlan->vlan_ip,
                              vlan->vlan_ip, vlan->vlan_id);
            }
      }
}

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(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
      struct arphdr *arp;
      struct slave *slave;
      struct bonding *bond;
      unsigned char *arp_ptr;
      __be32 sip, tip;

      if (dev_net(dev) != &init_net)
            goto out;

      if (!(dev->priv_flags & IFF_BONDING) || !(dev->flags & IFF_MASTER))
            goto out;

      bond = netdev_priv(dev);
      read_lock(&bond->lock);

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

      slave = bond_get_slave_by_dev(bond, orig_dev);
      if (!slave || !slave_do_arp_validate(bond, slave))
            goto out_unlock;

      if (!pskb_may_pull(skb, arp_hdr_len(dev)))
            goto out_unlock;

      arp = arp_hdr(skb);
      if (arp->ar_hln != 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 += dev->addr_len;
      memcpy(&sip, arp_ptr, 4);
      arp_ptr += 4 + 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, slave->state,
            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 (slave->state == BOND_STATE_ACTIVE)
            bond_validate_arp(bond, slave, sip, tip);
      else
            bond_validate_arp(bond, slave, tip, sip);

out_unlock:
      read_unlock(&bond->lock);
out:
      dev_kfree_skb(skb);
      return NET_RX_SUCCESS;
}

/*
 * 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;
      int i;

      read_lock(&bond->lock);

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

      if (bond->kill_timers)
            goto out;

      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) {
            if (slave->link != BOND_LINK_UP) {
                  if (time_before_eq(jiffies, dev_trans_start(slave->dev) + delta_in_ticks) &&
                      time_before_eq(jiffies, slave->dev->last_rx + delta_in_ticks)) {

                        slave->link  = BOND_LINK_UP;
                        slave->state = BOND_STATE_ACTIVE;

                        /* 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(DRV_NAME
                                     ": %s: link status definitely "
                                     "up for interface %s, ",
                                     bond->dev->name,
                                     slave->dev->name);
                              do_failover = 1;
                        } else {
                              pr_info(DRV_NAME
                                     ": %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_after_eq(jiffies, dev_trans_start(slave->dev) + 2*delta_in_ticks) ||
                      (time_after_eq(jiffies, slave->dev->last_rx + 2*delta_in_ticks))) {

                        slave->link  = BOND_LINK_DOWN;
                        slave->state = BOND_STATE_BACKUP;

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

                        pr_info(DRV_NAME
                               ": %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) {
            write_lock_bh(&bond->curr_slave_lock);

            bond_select_active_slave(bond);

            write_unlock_bh(&bond->curr_slave_lock);
      }

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

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

            if (slave->link != BOND_LINK_UP) {
                  if (time_before_eq(jiffies, slave_last_rx(bond, slave) +
                                 delta_in_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_after_eq(jiffies, slave->jiffies +
                           2 * delta_in_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 (slave->state == BOND_STATE_BACKUP &&
                !bond->current_arp_slave &&
                time_after(jiffies, slave_last_rx(bond, slave) +
                         3 * delta_in_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)
             */
            if ((slave->state == BOND_STATE_ACTIVE) &&
                (time_after_eq(jiffies, dev_trans_start(slave->dev) +
                            2 * delta_in_ticks) ||
                  (time_after_eq(jiffies, slave_last_rx(bond, slave)
                             + 2 * delta_in_ticks)))) {
                  slave->new_link = BOND_LINK_DOWN;
                  commit++;
            }
      }

      read_lock(&bond->curr_slave_lock);

      /*
       * Trigger a commit if the primary option setting has changed.
       */
      if (bond->primary_slave &&
          (bond->primary_slave != bond->curr_active_slave) &&
          (bond->primary_slave->link == BOND_LINK_UP))
            commit++;

      read_unlock(&bond->curr_slave_lock);

      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;

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

            case BOND_LINK_UP:
                  write_lock_bh(&bond->curr_slave_lock);

                  if (!bond->curr_active_slave &&
                      time_before_eq(jiffies, dev_trans_start(slave->dev) +
                                 delta_in_ticks)) {
                        slave->link = BOND_LINK_UP;
                        bond_change_active_slave(bond, slave);
                        bond->current_arp_slave = NULL;

                        pr_info(DRV_NAME
                               ": %s: %s is up and now the "
                               "active interface\n",
                               bond->dev->name, slave->dev->name);

                  } else if (bond->curr_active_slave != slave) {
                        /* this slave has just come up but we
                         * already have a current slave; this can
                         * also happen if bond_enslave adds a new
                         * slave that is up while we are searching
                         * for a new slave
                         */
                        slave->link = BOND_LINK_UP;
                        bond_set_slave_inactive_flags(slave);
                        bond->current_arp_slave = NULL;

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

                  write_unlock_bh(&bond->curr_slave_lock);

                  break;

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

                  slave->link = BOND_LINK_DOWN;

                  if (slave == bond->curr_active_slave) {
                        pr_info(DRV_NAME
                               ": %s: link status down for active "
                               "interface %s, disabling it\n",
                               bond->dev->name, slave->dev->name);

                        bond_set_slave_inactive_flags(slave);

                        write_lock_bh(&bond->curr_slave_lock);

                        bond_select_active_slave(bond);
                        if (bond->curr_active_slave)
                              bond->curr_active_slave->jiffies =
                                    jiffies;

                        write_unlock_bh(&bond->curr_slave_lock);

                        bond->current_arp_slave = NULL;

                  } else if (slave->state == BOND_STATE_BACKUP) {
                        pr_info(DRV_NAME
                               ": %s: backup interface %s is now down\n",
                               bond->dev->name, slave->dev->name);

                        bond_set_slave_inactive_flags(slave);
                  }
                  break;

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

      /*
       * No race with changes to primary via sysfs, as we hold rtnl.
       */
      if (bond->primary_slave &&
          (bond->primary_slave != bond->curr_active_slave) &&
          (bond->primary_slave->link == BOND_LINK_UP)) {
            write_lock_bh(&bond->curr_slave_lock);
            bond_change_active_slave(bond, bond->primary_slave);
            write_unlock_bh(&bond->curr_slave_lock);
      }

      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(DRV_NAME "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(DRV_NAME
                         ": %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);
      int delta_in_ticks;

      read_lock(&bond->lock);

      if (bond->kill_timers)
            goto out;

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

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

      if (bond->send_grat_arp) {
            read_lock(&bond->curr_slave_lock);
            bond_send_gratuitous_arp(bond);
            read_unlock(&bond->curr_slave_lock);
      }

      if (bond->send_unsol_na) {
            read_lock(&bond->curr_slave_lock);
            bond_send_unsolicited_na(bond);
            read_unlock(&bond->curr_slave_lock);
      }

      if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
            read_unlock(&bond->lock);
            rtnl_lock();
            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);
out:
      read_unlock(&bond->lock);
}

/*------------------------------ proc/seq_file-------------------------------*/

#ifdef CONFIG_PROC_FS

static void *bond_info_seq_start(struct seq_file *seq, loff_t *pos)
      __acquires(&dev_base_lock)
      __acquires(&bond->lock)
{
      struct bonding *bond = seq->private;
      loff_t off = 0;
      struct slave *slave;
      int i;

      /* make sure the bond won't be taken away */
      read_lock(&dev_base_lock);
      read_lock(&bond->lock);

      if (*pos == 0)
            return SEQ_START_TOKEN;

      bond_for_each_slave(bond, slave, i) {
            if (++off == *pos)
                  return slave;
      }

      return NULL;
}

static void *bond_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      struct bonding *bond = seq->private;
      struct slave *slave = v;

      ++*pos;
      if (v == SEQ_START_TOKEN)
            return bond->first_slave;

      slave = slave->next;

      return (slave == bond->first_slave) ? NULL : slave;
}

static void bond_info_seq_stop(struct seq_file *seq, void *v)
      __releases(&bond->lock)
      __releases(&dev_base_lock)
{
      struct bonding *bond = seq->private;

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

static void bond_info_show_master(struct seq_file *seq)
{
      struct bonding *bond = seq->private;
      struct slave *curr;
      int i;

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

      seq_printf(seq, "Bonding Mode: %s",
               bond_mode_name(bond->params.mode));

      if (bond->params.mode == BOND_MODE_ACTIVEBACKUP &&
          bond->params.fail_over_mac)
            seq_printf(seq, " (fail_over_mac %s)",
               fail_over_mac_tbl[bond->params.fail_over_mac].modename);

      seq_printf(seq, "\n");

      if (bond->params.mode == BOND_MODE_XOR ||
            bond->params.mode == BOND_MODE_8023AD) {
            seq_printf(seq, "Transmit Hash Policy: %s (%d)\n",
                  xmit_hashtype_tbl[bond->params.xmit_policy].modename,
                  bond->params.xmit_policy);
      }

      if (USES_PRIMARY(bond->params.mode)) {
            seq_printf(seq, "Primary Slave: %s\n",
                     (bond->primary_slave) ?
                     bond->primary_slave->dev->name : "None");

            seq_printf(seq, "Currently Active Slave: %s\n",
                     (curr) ? curr->dev->name : "None");
      }

      seq_printf(seq, "MII Status: %s\n", netif_carrier_ok(bond->dev) ?
               "up" : "down");
      seq_printf(seq, "MII Polling Interval (ms): %d\n", bond->params.miimon);
      seq_printf(seq, "Up Delay (ms): %d\n",
               bond->params.updelay * bond->params.miimon);
      seq_printf(seq, "Down Delay (ms): %d\n",
               bond->params.downdelay * bond->params.miimon);


      /* ARP information */
      if (bond->params.arp_interval > 0) {
            int printed = 0;
            seq_printf(seq, "ARP Polling Interval (ms): %d\n",
                        bond->params.arp_interval);

            seq_printf(seq, "ARP IP target/s (n.n.n.n form):");

            for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
                  if (!bond->params.arp_targets[i])
                        break;
                  if (printed)
                        seq_printf(seq, ",");
                  seq_printf(seq, " %pI4", &bond->params.arp_targets[i]);
                  printed = 1;
            }
            seq_printf(seq, "\n");
      }

      if (bond->params.mode == BOND_MODE_8023AD) {
            struct ad_info ad_info;

            seq_puts(seq, "\n802.3ad info\n");
            seq_printf(seq, "LACP rate: %s\n",
                     (bond->params.lacp_fast) ? "fast" : "slow");
            seq_printf(seq, "Aggregator selection policy (ad_select): %s\n",
                     ad_select_tbl[bond->params.ad_select].modename);

            if (bond_3ad_get_active_agg_info(bond, &ad_info)) {
                  seq_printf(seq, "bond %s has no active aggregator\n",
                           bond->dev->name);
            } else {
                  seq_printf(seq, "Active Aggregator Info:\n");

                  seq_printf(seq, "\tAggregator ID: %d\n",
                           ad_info.aggregator_id);
                  seq_printf(seq, "\tNumber of ports: %d\n",
                           ad_info.ports);
                  seq_printf(seq, "\tActor Key: %d\n",
                           ad_info.actor_key);
                  seq_printf(seq, "\tPartner Key: %d\n",
                           ad_info.partner_key);
                  seq_printf(seq, "\tPartner Mac Address: %pM\n",
                           ad_info.partner_system);
            }
      }
}

static void bond_info_show_slave(struct seq_file *seq,
                         const struct slave *slave)
{
      struct bonding *bond = seq->private;

      seq_printf(seq, "\nSlave Interface: %s\n", slave->dev->name);
      seq_printf(seq, "MII Status: %s\n",
               (slave->link == BOND_LINK_UP) ?  "up" : "down");
      seq_printf(seq, "Link Failure Count: %u\n",
               slave->link_failure_count);

      seq_printf(seq, "Permanent HW addr: %pM\n", slave->perm_hwaddr);

      if (bond->params.mode == BOND_MODE_8023AD) {
            const struct aggregator *agg
                  = SLAVE_AD_INFO(slave).port.aggregator;

            if (agg)
                  seq_printf(seq, "Aggregator ID: %d\n",
                           agg->aggregator_identifier);
            else
                  seq_puts(seq, "Aggregator ID: N/A\n");
      }
}

static int bond_info_seq_show(struct seq_file *seq, void *v)
{
      if (v == SEQ_START_TOKEN) {
            seq_printf(seq, "%s\n", version);
            bond_info_show_master(seq);
      } else
            bond_info_show_slave(seq, v);

      return 0;
}

static const struct seq_operations bond_info_seq_ops = {
      .start = bond_info_seq_start,
      .next  = bond_info_seq_next,
      .stop  = bond_info_seq_stop,
      .show  = bond_info_seq_show,
};

static int bond_info_open(struct inode *inode, struct file *file)
{
      struct seq_file *seq;
      struct proc_dir_entry *proc;
      int res;

      res = seq_open(file, &bond_info_seq_ops);
      if (!res) {
            /* recover the pointer buried in proc_dir_entry data */
            seq = file->private_data;
            proc = PDE(inode);
            seq->private = proc->data;
      }

      return res;
}

static const struct file_operations bond_info_fops = {
      .owner   = THIS_MODULE,
      .open    = bond_info_open,
      .read    = seq_read,
      .llseek  = seq_lseek,
      .release = seq_release,
};

static int bond_create_proc_entry(struct bonding *bond)
{
      struct net_device *bond_dev = bond->dev;

      if (bond_proc_dir) {
            bond->proc_entry = proc_create_data(bond_dev->name,
                                        S_IRUGO, bond_proc_dir,
                                        &bond_info_fops, bond);
            if (bond->proc_entry == NULL)
                  pr_warning(DRV_NAME
                         ": Warning: Cannot create /proc/net/%s/%s\n",
                         DRV_NAME, bond_dev->name);
            else
                  memcpy(bond->proc_file_name, bond_dev->name, IFNAMSIZ);
      }

      return 0;
}

static void bond_remove_proc_entry(struct bonding *bond)
{
      if (bond_proc_dir && bond->proc_entry) {
            remove_proc_entry(bond->proc_file_name, bond_proc_dir);
            memset(bond->proc_file_name, 0, IFNAMSIZ);
            bond->proc_entry = NULL;
      }
}

/* Create the bonding directory under /proc/net, if doesn't exist yet.
 * Caller must hold rtnl_lock.
 */
static void bond_create_proc_dir(void)
{
      if (!bond_proc_dir) {
            bond_proc_dir = proc_mkdir(DRV_NAME, init_net.proc_net);
            if (!bond_proc_dir)
                  pr_warning(DRV_NAME
                        ": Warning: cannot create /proc/net/%s\n",
                        DRV_NAME);
      }
}

/* Destroy the bonding directory under /proc/net, if empty.
 * Caller must hold rtnl_lock.
 */
static void bond_destroy_proc_dir(void)
{
      if (bond_proc_dir) {
            remove_proc_entry(DRV_NAME, init_net.proc_net);
            bond_proc_dir = NULL;
      }
}

#else /* !CONFIG_PROC_FS */

static int bond_create_proc_entry(struct bonding *bond)
{
}

static void bond_remove_proc_entry(struct bonding *bond)
{
}

static void bond_create_proc_dir(void)
{
}

static void bond_destroy_proc_dir(void)
{
}

#endif /* CONFIG_PROC_FS */


/*-------------------------- 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_destroy_sysfs_entry(bond);
      bond_create_sysfs_entry(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_release_all(event_bond->dev);
            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);

      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_CHANGE:
            if (bond->params.mode == BOND_MODE_8023AD || bond_is_lb(bond)) {
                  struct slave *slave;

                  slave = bond_get_slave_by_dev(bond, slave_dev);
                  if (slave) {
                        u16 old_speed = slave->speed;
                        u16 old_duplex = slave->duplex;

                        bond_update_speed_duplex(slave);

                        if (bond_is_lb(bond))
                              break;

                        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;

      if (dev_net(event_dev) != &init_net)
            return NOTIFY_DONE;

      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;
}

/*
 * bond_inetaddr_event: handle inetaddr notifier chain events.
 *
 * We keep track of device IPs primarily to use as source addresses in
 * ARP monitor probes (rather than spewing out broadcasts all the time).
 *
 * We track one IP for the main device (if it has one), plus one per VLAN.
 */
static int bond_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
{
      struct in_ifaddr *ifa = ptr;
      struct net_device *vlan_dev, *event_dev = ifa->ifa_dev->dev;
      struct bonding *bond;
      struct vlan_entry *vlan;

      if (dev_net(ifa->ifa_dev->dev) != &init_net)
            return NOTIFY_DONE;

      list_for_each_entry(bond, &bond_dev_list, bond_list) {
            if (bond->dev == event_dev) {
                  switch (event) {
                  case NETDEV_UP:
                        bond->master_ip = ifa->ifa_local;
                        return NOTIFY_OK;
                  case NETDEV_DOWN:
                        bond->master_ip = bond_glean_dev_ip(bond->dev);
                        return NOTIFY_OK;
                  default:
                        return NOTIFY_DONE;
                  }
            }

            list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                  vlan_dev = vlan_group_get_device(bond->vlgrp, vlan->vlan_id);
                  if (vlan_dev == event_dev) {
                        switch (event) {
                        case NETDEV_UP:
                              vlan->vlan_ip = ifa->ifa_local;
                              return NOTIFY_OK;
                        case NETDEV_DOWN:
                              vlan->vlan_ip =
                                    bond_glean_dev_ip(vlan_dev);
                              return NOTIFY_OK;
                        default:
                              return NOTIFY_DONE;
                        }
                  }
            }
      }
      return NOTIFY_DONE;
}

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

static struct notifier_block bond_inetaddr_notifier = {
      .notifier_call = bond_inetaddr_event,
};

/*-------------------------- Packet type handling ---------------------------*/

/* register to receive lacpdus on a bond */
static void bond_register_lacpdu(struct bonding *bond)
{
      struct packet_type *pk_type = &(BOND_AD_INFO(bond).ad_pkt_type);

      /* initialize packet type */
      pk_type->type = PKT_TYPE_LACPDU;
      pk_type->dev = bond->dev;
      pk_type->func = bond_3ad_lacpdu_recv;

      dev_add_pack(pk_type);
}

/* unregister to receive lacpdus on a bond */
static void bond_unregister_lacpdu(struct bonding *bond)
{
      dev_remove_pack(&(BOND_AD_INFO(bond).ad_pkt_type));
}

void bond_register_arp(struct bonding *bond)
{
      struct packet_type *pt = &bond->arp_mon_pt;

      if (pt->type)
            return;

      pt->type = htons(ETH_P_ARP);
      pt->dev = bond->dev;
      pt->func = bond_arp_rcv;
      dev_add_pack(pt);
}

void bond_unregister_arp(struct bonding *bond)
{
      struct packet_type *pt = &bond->arp_mon_pt;

      dev_remove_pack(pt);
      pt->type = 0;
}

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

/*
 * Hash for the output device based upon layer 2 and layer 3 data. If
 * the packet is not IP mimic bond_xmit_hash_policy_l2()
 */
static int bond_xmit_hash_policy_l23(struct sk_buff *skb,
                             struct net_device *bond_dev, int count)
{
      struct ethhdr *data = (struct ethhdr *)skb->data;
      struct iphdr *iph = ip_hdr(skb);

      if (skb->protocol == htons(ETH_P_IP)) {
            return ((ntohl(iph->saddr ^ iph->daddr) & 0xffff) ^
                  (data->h_dest[5] ^ bond_dev->dev_addr[5])) % count;
      }

      return (data->h_dest[5] ^ bond_dev->dev_addr[5]) % 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, mimic bond_xmit_hash_policy_l2()
 */
static int bond_xmit_hash_policy_l34(struct sk_buff *skb,
                            struct net_device *bond_dev, int count)
{
      struct ethhdr *data = (struct ethhdr *)skb->data;
      struct iphdr *iph = ip_hdr(skb);
      __be16 *layer4hdr = (__be16 *)((u32 *)iph + iph->ihl);
      int layer4_xor = 0;

      if (skb->protocol == htons(ETH_P_IP)) {
            if (!(iph->frag_off & htons(IP_MF|IP_OFFSET)) &&
                (iph->protocol == IPPROTO_TCP ||
                 iph->protocol == IPPROTO_UDP)) {
                  layer4_xor = ntohs((*layer4hdr ^ *(layer4hdr + 1)));
            }
            return (layer4_xor ^
                  ((ntohl(iph->saddr ^ iph->daddr)) & 0xffff)) % count;

      }

      return (data->h_dest[5] ^ bond_dev->dev_addr[5]) % count;
}

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

      return (data->h_dest[5] ^ bond_dev->dev_addr[5]) % count;
}

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

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

      bond->kill_timers = 0;

      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))) {
                  /* something went wrong - fail the open operation */
                  return -1;
            }

            INIT_DELAYED_WORK(&bond->alb_work, bond_alb_monitor);
            queue_delayed_work(bond->wq, &bond->alb_work, 0);
      }

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

      if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
            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);

            queue_delayed_work(bond->wq, &bond->arp_work, 0);
            if (bond->params.arp_validate)
                  bond_register_arp(bond);
      }

      if (bond->params.mode == BOND_MODE_8023AD) {
            INIT_DELAYED_WORK(&bond->ad_work, bond_3ad_state_machine_handler);
            queue_delayed_work(bond->wq, &bond->ad_work, 0);
            /* register to receive LACPDUs */
            bond_register_lacpdu(bond);
            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);

      if (bond->params.mode == BOND_MODE_8023AD) {
            /* Unregister the receive of LACPDUs */
            bond_unregister_lacpdu(bond);
      }

      if (bond->params.arp_validate)
            bond_unregister_arp(bond);

      write_lock_bh(&bond->lock);

      bond->send_grat_arp = 0;
      bond->send_unsol_na = 0;

      /* signal timers not to re-arm */
      bond->kill_timers = 1;

      write_unlock_bh(&bond->lock);

      if (bond->params.miimon) {  /* link check interval, in milliseconds. */
            cancel_delayed_work(&bond->mii_work);
      }

      if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
            cancel_delayed_work(&bond->arp_work);
      }

      switch (bond->params.mode) {
      case BOND_MODE_8023AD:
            cancel_delayed_work(&bond->ad_work);
            break;
      case BOND_MODE_TLB:
      case BOND_MODE_ALB:
            cancel_delayed_work(&bond->alb_work);
            break;
      default:
            break;
      }


      if (bond_is_lb(bond)) {
            /* Must be called only after all
             * slaves have been released
             */
            bond_alb_deinitialize(bond);
      }

      return 0;
}

static struct net_device_stats *bond_get_stats(struct net_device *bond_dev)
{
      struct bonding *bond = netdev_priv(bond_dev);
      struct net_device_stats *stats = &bond->stats;
      struct net_device_stats local_stats;
      struct slave *slave;
      int i;

      memset(&local_stats, 0, sizeof(struct net_device_stats));

      read_lock_bh(&bond->lock);

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

            local_stats.rx_packets += sstats->rx_packets;
            local_stats.rx_bytes += sstats->rx_bytes;
            local_stats.rx_errors += sstats->rx_errors;
            local_stats.rx_dropped += sstats->rx_dropped;

            local_stats.tx_packets += sstats->tx_packets;
            local_stats.tx_bytes += sstats->tx_bytes;
            local_stats.tx_errors += sstats->tx_errors;
            local_stats.tx_dropped += sstats->tx_dropped;

            local_stats.multicast += sstats->multicast;
            local_stats.collisions += sstats->collisions;

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

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

      memcpy(stats, &local_stats, sizeof(struct net_device_stats));

      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(&init_net, 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 void bond_set_multicast_list(struct net_device *bond_dev)
{
      struct bonding *bond = netdev_priv(bond_dev);
      struct dev_mc_list *dmi;

      /*
       * Do promisc before checking multicast_mode
       */
      if ((bond_dev->flags & IFF_PROMISC) && !(bond->flags & IFF_PROMISC))
            /*
             * FIXME: Need to handle the error when one of the multi-slaves
             * encounters error.
             */
            bond_set_promiscuity(bond, 1);


      if (!(bond_dev->flags & IFF_PROMISC) && (bond->flags & IFF_PROMISC))
            bond_set_promiscuity(bond, -1);


      /* set allmulti flag to slaves */
      if ((bond_dev->flags & IFF_ALLMULTI) && !(bond->flags & IFF_ALLMULTI))
            /*
             * FIXME: Need to handle the error when one of the multi-slaves
             * encounters error.
             */
            bond_set_allmulti(bond, 1);


      if (!(bond_dev->flags & IFF_ALLMULTI) && (bond->flags & IFF_ALLMULTI))
            bond_set_allmulti(bond, -1);


      read_lock(&bond->lock);

      bond->flags = bond_dev->flags;

      /* looking for addresses to add to slaves' mc list */
      for (dmi = bond_dev->mc_list; dmi; dmi = dmi->next) {
            if (!bond_mc_list_find_dmi(dmi, bond->mc_list))
                  bond_mc_add(bond, dmi->dmi_addr, dmi->dmi_addrlen);
      }

      /* looking for addresses to delete from slaves' list */
      for (dmi = bond->mc_list; dmi; dmi = dmi->next) {
            if (!bond_mc_list_find_dmi(dmi, bond_dev->mc_list))
                  bond_mc_delete(bond, dmi->dmi_addr, dmi->dmi_addrlen);
      }

      /* save master's multicast list */
      bond_mc_list_destroy(bond);
      bond_mc_list_copy(bond_dev->mc_list, bond, GFP_ATOMIC);

      read_unlock(&bond->lock);
}

static int bond_neigh_setup(struct net_device *dev, struct neigh_parms *parms)
{
      struct bonding *bond = netdev_priv(dev);
      struct slave *slave = bond->first_slave;

      if (slave) {
            const struct net_device_ops *slave_ops
                  = slave->dev->netdev_ops;
            if (slave_ops->ndo_neigh_setup)
                  return slave_ops->ndo_neigh_setup(slave->dev, parms);
      }
      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;

      read_lock(&bond->lock);

      if (!BOND_IS_OK(bond))
            goto out;

      /*
       * 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) &&
                (slave->state == BOND_STATE_ACTIVE)) {
                  res = bond_dev_queue_xmit(bond, skb, slave->dev);
                  break;
            }
      }

out:
      if (res) {
            /* no suitable interface, frame not sent */
            dev_kfree_skb(skb);
      }
      read_unlock(&bond->lock);
      return 0;
}


/*
 * 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->lock);
      read_lock(&bond->curr_slave_lock);

      if (!BOND_IS_OK(bond))
            goto out;

      if (!bond->curr_active_slave)
            goto out;

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

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

      read_unlock(&bond->curr_slave_lock);
      read_unlock(&bond->lock);
      return 0;
}

/*
 * 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;

      read_lock(&bond->lock);

      if (!BOND_IS_OK(bond))
            goto out;

      slave_no = bond->xmit_hash_policy(skb, bond_dev, 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) &&
                (slave->state == BOND_STATE_ACTIVE)) {
                  res = bond_dev_queue_xmit(bond, skb, slave->dev);
                  break;
            }
      }

out:
      if (res) {
            /* no suitable interface, frame not sent */
            dev_kfree_skb(skb);
      }
      read_unlock(&bond->lock);
      return 0;
}

/*
 * 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->lock);

      if (!BOND_IS_OK(bond))
            goto out;

      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) &&
                (slave->state == BOND_STATE_ACTIVE)) {
                  if (tx_dev) {
                        struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
                        if (!skb2) {
                              pr_err(DRV_NAME
                                     ": %s: Error: bond_xmit_broadcast(): "
                                     "skb_clone() failed\n",
                                     bond_dev->name);
                              continue;
                        }

                        res = bond_dev_queue_xmit(bond, skb2, tx_dev);
                        if (res) {
                              dev_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 */
            dev_kfree_skb(skb);

      /* frame sent to all suitable interfaces */
      read_unlock(&bond->lock);
      return 0;
}

/*------------------------- 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;
      }
}

static int bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
      const struct bonding *bond = netdev_priv(dev);

      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(DRV_NAME ": %s: Error: Unknown bonding mode %d\n",
                 dev->name, bond->params.mode);
            WARN_ON_ONCE(1);
            dev_kfree_skb(skb);
            return NETDEV_TX_OK;
      }
}


/*
 * 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_master_3ad_flags(bond);
            bond_set_xmit_hash_policy(bond);
            break;
      case BOND_MODE_ALB:
            bond_set_master_alb_flags(bond);
            /* FALLTHRU */
      case BOND_MODE_TLB:
            break;
      default:
            /* Should never happen, mode already checked */
            pr_err(DRV_NAME
                   ": %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,
      .get_tx_csum            = ethtool_op_get_tx_csum,
      .get_sg                 = ethtool_op_get_sg,
      .get_tso          = ethtool_op_get_tso,
      .get_ufo          = ethtool_op_get_ufo,
      .get_flags        = ethtool_op_get_flags,
};

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_get_stats          = bond_get_stats,
      .ndo_do_ioctl           = bond_do_ioctl,
      .ndo_set_multicast_list = 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_register   = bond_vlan_rx_register,
      .ndo_vlan_rx_add_vid    = bond_vlan_rx_add_vid,
      .ndo_vlan_rx_kill_vid   = bond_vlan_rx_kill_vid,
};

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 = free_netdev;

      /* 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;

      if (bond->params.arp_interval)
            bond_dev->priv_flags |= IFF_MASTER_ARPMON;

      /* 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->features |= (NETIF_F_HW_VLAN_TX |
                         NETIF_F_HW_VLAN_RX |
                         NETIF_F_HW_VLAN_FILTER);

}

static void bond_work_cancel_all(struct bonding *bond)
{
      write_lock_bh(&bond->lock);
      bond->kill_timers = 1;
      write_unlock_bh(&bond->lock);

      if (bond->params.miimon && delayed_work_pending(&bond->mii_work))
            cancel_delayed_work(&bond->mii_work);

      if (bond->params.arp_interval && delayed_work_pending(&bond->arp_work))
            cancel_delayed_work(&bond->arp_work);

      if (bond->params.mode == BOND_MODE_ALB &&
          delayed_work_pending(&bond->alb_work))
            cancel_delayed_work(&bond->alb_work);

      if (bond->params.mode == BOND_MODE_8023AD &&
          delayed_work_pending(&bond->ad_work))
            cancel_delayed_work(&bond->ad_work);
}

/* De-initialize device specific data.
 * Caller must hold rtnl_lock.
 */
static void bond_deinit(struct net_device *bond_dev)
{
      struct bonding *bond = netdev_priv(bond_dev);

      list_del(&bond->bond_list);

      bond_work_cancel_all(bond);

      bond_remove_proc_entry(bond);
}

/* Unregister and free all bond devices.
 * Caller must hold rtnl_lock.
 */
static void bond_free_all(void)
{
      struct bonding *bond, *nxt;

      list_for_each_entry_safe(bond, nxt, &bond_dev_list, bond_list) {
            struct net_device *bond_dev = bond->dev;

            bond_work_cancel_all(bond);
            /* Release the bonded slaves */
            bond_release_all(bond_dev);
            unregister_netdevice(bond_dev);
      }

      bond_destroy_proc_dir();
}

/*------------------------- 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;

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

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

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

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

      /* reset values for 802.3ad */
      if (bond_mode == BOND_MODE_8023AD) {
            if (!miimon) {
                  pr_warning(DRV_NAME
                         ": 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;
            }
      }

      /* reset values for TLB/ALB */
      if ((bond_mode == BOND_MODE_TLB) ||
          (bond_mode == BOND_MODE_ALB)) {
            if (!miimon) {
                  pr_warning(DRV_NAME
                         ": 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) {
            printk(KERN_NOTICE DRV_NAME
                   ": 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(DRV_NAME
                         ": 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(DRV_NAME
                         ": 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(DRV_NAME
                         ": 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(DRV_NAME
                         ": 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(DRV_NAME
                   ": 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 */
            if (!isdigit(arp_ip_target[arp_ip_count][0])) {
                  pr_warning(DRV_NAME
                         ": 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 {
                  __be32 ip = in_aton(arp_ip_target[arp_ip_count]);
                  arp_target[arp_ip_count] = ip;
            }
      }

      if (arp_interval && !arp_ip_count) {
            /* don't allow arping if no arp_ip_target given... */
            pr_warning(DRV_NAME
                   ": 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(DRV_NAME
                         ": arp_validate only supported in active-backup mode\n");
                  return -EINVAL;
            }
            if (!arp_interval) {
                  pr_err(DRV_NAME
                         ": 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(DRV_NAME
                         ": Error: invalid arp_validate \"%s\"\n",
                         arp_validate == NULL ? "NULL" : arp_validate);
                  return -EINVAL;
            }
      } else
            arp_validate_value = 0;

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

            pr_info(DRV_NAME ": 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++)
                  printk(" %s", arp_ip_target[i]);

            printk("\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_warning(DRV_NAME
                   ": 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(DRV_NAME
                   ": Warning: %s primary device specified but has no "
                   "effect in %s mode\n",
                   primary, bond_mode_name(bond_mode));
            primary = NULL;
      }

      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(DRV_NAME
                         ": Error: invalid fail_over_mac \"%s\"\n",
                         arp_validate == NULL ? "NULL" : arp_validate);
                  return -EINVAL;
            }

            if (bond_mode != BOND_MODE_ACTIVEBACKUP)
                  pr_warning(DRV_NAME
                         ": 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_grat_arp = num_grat_arp;
      params->num_unsol_na = num_unsol_na;
      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->fail_over_mac = fail_over_mac_value;

      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 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);
}

/*
 * Called from registration process
 */
static int bond_init(struct net_device *bond_dev)
{
      struct bonding *bond = netdev_priv(bond_dev);

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

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

      bond_set_lockdep_class(bond_dev);

      netif_carrier_off(bond_dev);

      bond_create_proc_entry(bond);
      list_add_tail(&bond->bond_list, &bond_dev_list);

      return 0;
}

/* 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(const char *name)
{
      struct net_device *bond_dev;
      int res;

      rtnl_lock();
      /* Check to see if the bond already exists. */
      /* FIXME: pass netns from caller */
      if (name && __dev_get_by_name(&init_net, name)) {
            pr_err(DRV_NAME ": cannot add bond %s; already exists\n",
                   name);
            res = -EEXIST;
            goto out_rtnl;
      }

      bond_dev = alloc_netdev(sizeof(struct bonding), name ? name : "",
                        bond_setup);
      if (!bond_dev) {
            pr_err(DRV_NAME ": %s: eek! can't alloc netdev!\n",
                   name);
            res = -ENOMEM;
            goto out_rtnl;
      }

      if (!name) {
            res = dev_alloc_name(bond_dev, "bond%d");
            if (res < 0)
                  goto out_netdev;
      }

      res = register_netdevice(bond_dev);
      if (res < 0)
            goto out_bond;

      res = bond_create_sysfs_entry(netdev_priv(bond_dev));
      if (res < 0)
            goto out_unreg;

      rtnl_unlock();
      return 0;

out_unreg:
      unregister_netdevice(bond_dev);
out_bond:
      bond_deinit(bond_dev);
out_netdev:
      free_netdev(bond_dev);
out_rtnl:
      rtnl_unlock();
      return res;
}

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

      pr_info("%s", version);

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

      bond_create_proc_dir();

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

      res = bond_create_sysfs();
      if (res)
            goto err;

      register_netdevice_notifier(&bond_netdev_notifier);
      register_inetaddr_notifier(&bond_inetaddr_notifier);
      bond_register_ipv6_notifier();

      goto out;
err:
      rtnl_lock();
      bond_free_all();
      rtnl_unlock();
out:
      return res;

}

static void __exit bonding_exit(void)
{
      unregister_netdevice_notifier(&bond_netdev_notifier);
      unregister_inetaddr_notifier(&bond_inetaddr_notifier);
      bond_unregister_ipv6_notifier();

      bond_destroy_sysfs();

      rtnl_lock();
      bond_free_all();
      rtnl_unlock();
}

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, tadavis@lbl.gov and many others");

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