bonding: send IPv6 neighbor advertisement on failover

[deliverable/linux.git] / drivers / net / bonding / bond_sysfs.c

/*
 * Copyright(c) 2004-2005 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/in.h>
#include <linux/sysfs.h>
#include <linux/ctype.h>
#include <linux/inet.h>
#include <linux/rtnetlink.h>
#include <net/net_namespace.h>

/* #define BONDING_DEBUG 1 */
#include "bonding.h"
#define to_dev(obj)     container_of(obj,struct device,kobj)
#define to_bond(cd)     ((struct bonding *)(to_net_dev(cd)->priv))

/*---------------------------- Declarations -------------------------------*/


extern struct list_head bond_dev_list;
extern struct bond_params bonding_defaults;
extern struct bond_parm_tbl bond_mode_tbl[];
extern struct bond_parm_tbl bond_lacp_tbl[];
extern struct bond_parm_tbl xmit_hashtype_tbl[];
extern struct bond_parm_tbl arp_validate_tbl[];
extern struct bond_parm_tbl fail_over_mac_tbl[];

static int expected_refcount = -1;
/*--------------------------- Data Structures -----------------------------*/

/* Bonding sysfs lock.  Why can't we just use the subsystem lock?
 * Because kobject_register tries to acquire the subsystem lock.  If
 * we already hold the lock (which we would if the user was creating
 * a new bond through the sysfs interface), we deadlock.
 * This lock is only needed when deleting a bond - we need to make sure
 * that we don't collide with an ongoing ioctl.
 */

struct rw_semaphore bonding_rwsem;




/*------------------------------ Functions --------------------------------*/

/*
 * "show" function for the bond_masters attribute.
 * The class parameter is ignored.
 */
static ssize_t bonding_show_bonds(struct class *cls, char *buf)
{
        int res = 0;
        struct bonding *bond;

        down_read(&(bonding_rwsem));

        list_for_each_entry(bond, &bond_dev_list, bond_list) {
                if (res > (PAGE_SIZE - IFNAMSIZ)) {
                        /* not enough space for another interface name */
                        if ((PAGE_SIZE - res) > 10)
                                res = PAGE_SIZE - 10;
                        res += sprintf(buf + res, "++more++ ");
                        break;
                }
                res += sprintf(buf + res, "%s ", bond->dev->name);
        }
        if (res)
                buf[res-1] = '\n'; /* eat the leftover space */
        up_read(&(bonding_rwsem));
        return res;
}

/*
 * "store" function for the bond_masters attribute.  This is what
 * creates and deletes entire bonds.
 *
 * The class parameter is ignored.
 *
 */

static ssize_t bonding_store_bonds(struct class *cls, const char *buffer, size_t count)
{
        char command[IFNAMSIZ + 1] = {0, };
        char *ifname;
        int rv, res = count;
        struct bonding *bond;

        sscanf(buffer, "%16s", command); /* IFNAMSIZ*/
        ifname = command + 1;
        if ((strlen(command) <= 1) ||
            !dev_valid_name(ifname))
                goto err_no_cmd;

        if (command[0] == '+') {
                printk(KERN_INFO DRV_NAME
                        ": %s is being created...\n", ifname);
                rv = bond_create(ifname, &bonding_defaults);
                if (rv) {
                        printk(KERN_INFO DRV_NAME ": Bond creation failed.\n");
                        res = rv;
                }
                goto out;
        }

        if (command[0] == '-') {
                rtnl_lock();
                down_write(&bonding_rwsem);

                list_for_each_entry(bond, &bond_dev_list, bond_list)
                        if (strnicmp(bond->dev->name, ifname, IFNAMSIZ) == 0) {
                                /* check the ref count on the bond's kobject.
                                 * If it's > expected, then there's a file open,
                                 * and we have to fail.
                                 */
                                if (atomic_read(&bond->dev->dev.kobj.kref.refcount)
                                                        > expected_refcount){
                                        printk(KERN_INFO DRV_NAME
                                                ": Unable remove bond %s due to open references.\n",
                                                ifname);
                                        res = -EPERM;
                                        goto out_unlock;
                                }
                                printk(KERN_INFO DRV_NAME
                                        ": %s is being deleted...\n",
                                        bond->dev->name);
                                bond_destroy(bond);
                                goto out_unlock;
                        }

                printk(KERN_ERR DRV_NAME
                        ": unable to delete non-existent bond %s\n", ifname);
                res = -ENODEV;
                goto out_unlock;
        }

err_no_cmd:
        printk(KERN_ERR DRV_NAME
                ": no command found in bonding_masters. Use +ifname or -ifname.\n");
        return -EPERM;

out_unlock:
        up_write(&bonding_rwsem);
        rtnl_unlock();

        /* Always return either count or an error.  If you return 0, you'll
         * get called forever, which is bad.
         */
out:
        return res;
}
/* class attribute for bond_masters file.  This ends up in /sys/class/net */
static CLASS_ATTR(bonding_masters,  S_IWUSR | S_IRUGO,
                  bonding_show_bonds, bonding_store_bonds);

int bond_create_slave_symlinks(struct net_device *master, struct net_device *slave)
{
        char linkname[IFNAMSIZ+7];
        int ret = 0;

        /* first, create a link from the slave back to the master */
        ret = sysfs_create_link(&(slave->dev.kobj), &(master->dev.kobj),
                                "master");
        if (ret)
                return ret;
        /* next, create a link from the master to the slave */
        sprintf(linkname,"slave_%s",slave->name);
        ret = sysfs_create_link(&(master->dev.kobj), &(slave->dev.kobj),
                                linkname);
        return ret;

}

void bond_destroy_slave_symlinks(struct net_device *master, struct net_device *slave)
{
        char linkname[IFNAMSIZ+7];

        sysfs_remove_link(&(slave->dev.kobj), "master");
        sprintf(linkname,"slave_%s",slave->name);
        sysfs_remove_link(&(master->dev.kobj), linkname);
}


/*
 * Show the slaves in the current bond.
 */
static ssize_t bonding_show_slaves(struct device *d,
                                   struct device_attribute *attr, char *buf)
{
        struct slave *slave;
        int i, res = 0;
        struct bonding *bond = to_bond(d);

        read_lock(&bond->lock);
        bond_for_each_slave(bond, slave, i) {
                if (res > (PAGE_SIZE - IFNAMSIZ)) {
                        /* not enough space for another interface name */
                        if ((PAGE_SIZE - res) > 10)
                                res = PAGE_SIZE - 10;
                        res += sprintf(buf + res, "++more++ ");
                        break;
                }
                res += sprintf(buf + res, "%s ", slave->dev->name);
        }
        read_unlock(&bond->lock);
        if (res)
                buf[res-1] = '\n'; /* eat the leftover space */
        return res;
}

/*
 * Set the slaves in the current bond.  The bond interface must be
 * up for this to succeed.
 * This function is largely the same flow as bonding_update_bonds().
 */
static ssize_t bonding_store_slaves(struct device *d,
                                    struct device_attribute *attr,
                                    const char *buffer, size_t count)
{
        char command[IFNAMSIZ + 1] = { 0, };
        char *ifname;
        int i, res, found, ret = count;
        u32 original_mtu;
        struct slave *slave;
        struct net_device *dev = NULL;
        struct bonding *bond = to_bond(d);

        /* Quick sanity check -- is the bond interface up? */
        if (!(bond->dev->flags & IFF_UP)) {
                printk(KERN_WARNING DRV_NAME
                       ": %s: doing slave updates when interface is down.\n",
                       bond->dev->name);
        }

        /* Note:  We can't hold bond->lock here, as bond_create grabs it. */

        rtnl_lock();
        down_write(&(bonding_rwsem));

        sscanf(buffer, "%16s", command); /* IFNAMSIZ*/
        ifname = command + 1;
        if ((strlen(command) <= 1) ||
            !dev_valid_name(ifname))
                goto err_no_cmd;

        if (command[0] == '+') {

                /* Got a slave name in ifname.  Is it already in the list? */
                found = 0;
                read_lock(&bond->lock);
                bond_for_each_slave(bond, slave, i)
                        if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
                                printk(KERN_ERR DRV_NAME
                                       ": %s: Interface %s is already enslaved!\n",
                                       bond->dev->name, ifname);
                                ret = -EPERM;
                                read_unlock(&bond->lock);
                                goto out;
                        }

                read_unlock(&bond->lock);
                printk(KERN_INFO DRV_NAME ": %s: Adding slave %s.\n",
                       bond->dev->name, ifname);
                dev = dev_get_by_name(&init_net, ifname);
                if (!dev) {
                        printk(KERN_INFO DRV_NAME
                               ": %s: Interface %s does not exist!\n",
                               bond->dev->name, ifname);
                        ret = -EPERM;
                        goto out;
                }
                else
                        dev_put(dev);

                if (dev->flags & IFF_UP) {
                        printk(KERN_ERR DRV_NAME
                               ": %s: Error: Unable to enslave %s "
                               "because it is already up.\n",
                               bond->dev->name, dev->name);
                        ret = -EPERM;
                        goto out;
                }
                /* If this is the first slave, then we need to set
                   the master's hardware address to be the same as the
                   slave's. */
                if (!(*((u32 *) & (bond->dev->dev_addr[0])))) {
                        memcpy(bond->dev->dev_addr, dev->dev_addr,
                               dev->addr_len);
                }

                /* Set the slave's MTU to match the bond */
                original_mtu = dev->mtu;
                if (dev->mtu != bond->dev->mtu) {
                        if (dev->change_mtu) {
                                res = dev->change_mtu(dev,
                                                      bond->dev->mtu);
                                if (res) {
                                        ret = res;
                                        goto out;
                                }
                        } else {
                                dev->mtu = bond->dev->mtu;
                        }
                }
                res = bond_enslave(bond->dev, dev);
                bond_for_each_slave(bond, slave, i)
                        if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0)
                                slave->original_mtu = original_mtu;
                if (res) {
                        ret = res;
                }
                goto out;
        }

        if (command[0] == '-') {
                dev = NULL;
                original_mtu = 0;
                bond_for_each_slave(bond, slave, i)
                        if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
                                dev = slave->dev;
                                original_mtu = slave->original_mtu;
                                break;
                        }
                if (dev) {
                        printk(KERN_INFO DRV_NAME ": %s: Removing slave %s\n",
                                bond->dev->name, dev->name);
                                res = bond_release(bond->dev, dev);
                        if (res) {
                                ret = res;
                                goto out;
                        }
                        /* set the slave MTU to the default */
                        if (dev->change_mtu) {
                                dev->change_mtu(dev, original_mtu);
                        } else {
                                dev->mtu = original_mtu;
                        }
                }
                else {
                        printk(KERN_ERR DRV_NAME ": unable to remove non-existent slave %s for bond %s.\n",
                                ifname, bond->dev->name);
                        ret = -ENODEV;
                }
                goto out;
        }

err_no_cmd:
        printk(KERN_ERR DRV_NAME ": no command found in slaves file for bond %s. Use +ifname or -ifname.\n", bond->dev->name);
        ret = -EPERM;

out:
        up_write(&(bonding_rwsem));
        rtnl_unlock();
        return ret;
}

static DEVICE_ATTR(slaves, S_IRUGO | S_IWUSR, bonding_show_slaves, bonding_store_slaves);

/*
 * Show and set the bonding mode.  The bond interface must be down to
 * change the mode.
 */
static ssize_t bonding_show_mode(struct device *d,
                                 struct device_attribute *attr, char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%s %d\n",
                        bond_mode_tbl[bond->params.mode].modename,
                        bond->params.mode);
}

static ssize_t bonding_store_mode(struct device *d,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (bond->dev->flags & IFF_UP) {
                printk(KERN_ERR DRV_NAME
                       ": unable to update mode of %s because interface is up.\n",
                       bond->dev->name);
                ret = -EPERM;
                goto out;
        }

        new_value = bond_parse_parm(buf, bond_mode_tbl);
        if (new_value < 0)  {
                printk(KERN_ERR DRV_NAME
                       ": %s: Ignoring invalid mode value %.*s.\n",
                       bond->dev->name,
                       (int)strlen(buf) - 1, buf);
                ret = -EINVAL;
                goto out;
        } else {
                if (bond->params.mode == BOND_MODE_8023AD)
                        bond_unset_master_3ad_flags(bond);

                if (bond->params.mode == BOND_MODE_ALB)
                        bond_unset_master_alb_flags(bond);

                bond->params.mode = new_value;
                bond_set_mode_ops(bond, bond->params.mode);
                printk(KERN_INFO DRV_NAME ": %s: setting mode to %s (%d).\n",
                        bond->dev->name, bond_mode_tbl[new_value].modename, new_value);
        }
out:
        return ret;
}
static DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bonding_show_mode, bonding_store_mode);

/*
 * Show and set the bonding transmit hash method.  The bond interface must be down to
 * change the xmit hash policy.
 */
static ssize_t bonding_show_xmit_hash(struct device *d,
                                      struct device_attribute *attr,
                                      char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%s %d\n",
                       xmit_hashtype_tbl[bond->params.xmit_policy].modename,
                       bond->params.xmit_policy);
}

static ssize_t bonding_store_xmit_hash(struct device *d,
                                       struct device_attribute *attr,
                                       const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (bond->dev->flags & IFF_UP) {
                printk(KERN_ERR DRV_NAME
                       "%s: Interface is up. Unable to update xmit policy.\n",
                       bond->dev->name);
                ret = -EPERM;
                goto out;
        }

        new_value = bond_parse_parm(buf, xmit_hashtype_tbl);
        if (new_value < 0)  {
                printk(KERN_ERR DRV_NAME
                       ": %s: Ignoring invalid xmit hash policy value %.*s.\n",
                       bond->dev->name,
                       (int)strlen(buf) - 1, buf);
                ret = -EINVAL;
                goto out;
        } else {
                bond->params.xmit_policy = new_value;
                bond_set_mode_ops(bond, bond->params.mode);
                printk(KERN_INFO DRV_NAME ": %s: setting xmit hash policy to %s (%d).\n",
                        bond->dev->name, xmit_hashtype_tbl[new_value].modename, new_value);
        }
out:
        return ret;
}
static DEVICE_ATTR(xmit_hash_policy, S_IRUGO | S_IWUSR, bonding_show_xmit_hash, bonding_store_xmit_hash);

/*
 * Show and set arp_validate.
 */
static ssize_t bonding_show_arp_validate(struct device *d,
                                         struct device_attribute *attr,
                                         char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%s %d\n",
                       arp_validate_tbl[bond->params.arp_validate].modename,
                       bond->params.arp_validate);
}

static ssize_t bonding_store_arp_validate(struct device *d,
                                          struct device_attribute *attr,
                                          const char *buf, size_t count)
{
        int new_value;
        struct bonding *bond = to_bond(d);

        new_value = bond_parse_parm(buf, arp_validate_tbl);
        if (new_value < 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Ignoring invalid arp_validate value %s\n",
                       bond->dev->name, buf);
                return -EINVAL;
        }
        if (new_value && (bond->params.mode != BOND_MODE_ACTIVEBACKUP)) {
                printk(KERN_ERR DRV_NAME
                       ": %s: arp_validate only supported in active-backup mode.\n",
                       bond->dev->name);
                return -EINVAL;
        }
        printk(KERN_INFO DRV_NAME ": %s: setting arp_validate to %s (%d).\n",
               bond->dev->name, arp_validate_tbl[new_value].modename,
               new_value);

        if (!bond->params.arp_validate && new_value) {
                bond_register_arp(bond);
        } else if (bond->params.arp_validate && !new_value) {
                bond_unregister_arp(bond);
        }

        bond->params.arp_validate = new_value;

        return count;
}

static DEVICE_ATTR(arp_validate, S_IRUGO | S_IWUSR, bonding_show_arp_validate, bonding_store_arp_validate);

/*
 * Show and store fail_over_mac.  User only allowed to change the
 * value when there are no slaves.
 */
static ssize_t bonding_show_fail_over_mac(struct device *d, struct device_attribute *attr, char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%s %d\n",
                       fail_over_mac_tbl[bond->params.fail_over_mac].modename,
                       bond->params.fail_over_mac);
}

static ssize_t bonding_store_fail_over_mac(struct device *d, struct device_attribute *attr, const char *buf, size_t count)
{
        int new_value;
        struct bonding *bond = to_bond(d);

        if (bond->slave_cnt != 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Can't alter fail_over_mac with slaves in bond.\n",
                       bond->dev->name);
                return -EPERM;
        }

        new_value = bond_parse_parm(buf, fail_over_mac_tbl);
        if (new_value < 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Ignoring invalid fail_over_mac value %s.\n",
                       bond->dev->name, buf);
                return -EINVAL;
        }

        bond->params.fail_over_mac = new_value;
        printk(KERN_INFO DRV_NAME ": %s: Setting fail_over_mac to %s (%d).\n",
               bond->dev->name, fail_over_mac_tbl[new_value].modename,
               new_value);

        return count;
}

static DEVICE_ATTR(fail_over_mac, S_IRUGO | S_IWUSR, bonding_show_fail_over_mac, bonding_store_fail_over_mac);

/*
 * Show and set the arp timer interval.  There are two tricky bits
 * here.  First, if ARP monitoring is activated, then we must disable
 * MII monitoring.  Second, if the ARP timer isn't running, we must
 * start it.
 */
static ssize_t bonding_show_arp_interval(struct device *d,
                                         struct device_attribute *attr,
                                         char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.arp_interval);
}

static ssize_t bonding_store_arp_interval(struct device *d,
                                          struct device_attribute *attr,
                                          const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no arp_interval value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if (new_value < 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Invalid arp_interval value %d not in range 1-%d; rejected.\n",
                       bond->dev->name, new_value, INT_MAX);
                ret = -EINVAL;
                goto out;
        }

        printk(KERN_INFO DRV_NAME
               ": %s: Setting ARP monitoring interval to %d.\n",
               bond->dev->name, new_value);
        bond->params.arp_interval = new_value;
        if (bond->params.arp_interval)
                bond->dev->priv_flags |= IFF_MASTER_ARPMON;
        if (bond->params.miimon) {
                printk(KERN_INFO DRV_NAME
                       ": %s: ARP monitoring cannot be used with MII monitoring. "
                       "%s Disabling MII monitoring.\n",
                       bond->dev->name, bond->dev->name);
                bond->params.miimon = 0;
                if (delayed_work_pending(&bond->mii_work)) {
                        cancel_delayed_work(&bond->mii_work);
                        flush_workqueue(bond->wq);
                }
        }
        if (!bond->params.arp_targets[0]) {
                printk(KERN_INFO DRV_NAME
                       ": %s: ARP monitoring has been set up, "
                       "but no ARP targets have been specified.\n",
                       bond->dev->name);
        }
        if (bond->dev->flags & IFF_UP) {
                /* If the interface is up, we may need to fire off
                 * the ARP timer.  If the interface is down, the
                 * timer will get fired off when the open function
                 * is called.
                 */
                if (!delayed_work_pending(&bond->arp_work)) {
                        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);
                }
        }

out:
        return ret;
}
static DEVICE_ATTR(arp_interval, S_IRUGO | S_IWUSR , bonding_show_arp_interval, bonding_store_arp_interval);

/*
 * Show and set the arp targets.
 */
static ssize_t bonding_show_arp_targets(struct device *d,
                                        struct device_attribute *attr,
                                        char *buf)
{
        int i, res = 0;
        struct bonding *bond = to_bond(d);

        for (i = 0; i < BOND_MAX_ARP_TARGETS; i++) {
                if (bond->params.arp_targets[i])
                        res += sprintf(buf + res, "%pI4 ",
                                       &bond->params.arp_targets[i]);
        }
        if (res)
                buf[res-1] = '\n'; /* eat the leftover space */
        return res;
}

static ssize_t bonding_store_arp_targets(struct device *d,
                                         struct device_attribute *attr,
                                         const char *buf, size_t count)
{
        __be32 newtarget;
        int i = 0, done = 0, ret = count;
        struct bonding *bond = to_bond(d);
        __be32 *targets;

        targets = bond->params.arp_targets;
        newtarget = in_aton(buf + 1);
        /* look for adds */
        if (buf[0] == '+') {
                if ((newtarget == 0) || (newtarget == htonl(INADDR_BROADCAST))) {
                        printk(KERN_ERR DRV_NAME
                               ": %s: invalid ARP target %pI4 specified for addition\n",
                               bond->dev->name, &newtarget);
                        ret = -EINVAL;
                        goto out;
                }
                /* look for an empty slot to put the target in, and check for dupes */
                for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
                        if (targets[i] == newtarget) { /* duplicate */
                                printk(KERN_ERR DRV_NAME
                                       ": %s: ARP target %pI4 is already present\n",
                                       bond->dev->name, &newtarget);
                                if (done)
                                        targets[i] = 0;
                                ret = -EINVAL;
                                goto out;
                        }
                        if (targets[i] == 0 && !done) {
                                printk(KERN_INFO DRV_NAME
                                       ": %s: adding ARP target %pI4.\n",
                                       bond->dev->name, &newtarget);
                                done = 1;
                                targets[i] = newtarget;
                        }
                }
                if (!done) {
                        printk(KERN_ERR DRV_NAME
                               ": %s: ARP target table is full!\n",
                               bond->dev->name);
                        ret = -EINVAL;
                        goto out;
                }

        }
        else if (buf[0] == '-') {
                if ((newtarget == 0) || (newtarget == htonl(INADDR_BROADCAST))) {
                        printk(KERN_ERR DRV_NAME
                               ": %s: invalid ARP target %pI4 specified for removal\n",
                               bond->dev->name, &newtarget);
                        ret = -EINVAL;
                        goto out;
                }

                for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
                        if (targets[i] == newtarget) {
                                printk(KERN_INFO DRV_NAME
                                       ": %s: removing ARP target %pI4.\n",
                                       bond->dev->name, &newtarget);
                                targets[i] = 0;
                                done = 1;
                        }
                }
                if (!done) {
                        printk(KERN_INFO DRV_NAME
                               ": %s: unable to remove nonexistent ARP target %pI4.\n",
                               bond->dev->name, &newtarget);
                        ret = -EINVAL;
                        goto out;
                }
        }
        else {
                printk(KERN_ERR DRV_NAME ": no command found in arp_ip_targets file for bond %s. Use +<addr> or -<addr>.\n",
                        bond->dev->name);
                ret = -EPERM;
                goto out;
        }

out:
        return ret;
}
static DEVICE_ATTR(arp_ip_target, S_IRUGO | S_IWUSR , bonding_show_arp_targets, bonding_store_arp_targets);

/*
 * Show and set the up and down delays.  These must be multiples of the
 * MII monitoring value, and are stored internally as the multiplier.
 * Thus, we must translate to MS for the real world.
 */
static ssize_t bonding_show_downdelay(struct device *d,
                                      struct device_attribute *attr,
                                      char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.downdelay * bond->params.miimon);
}

static ssize_t bonding_store_downdelay(struct device *d,
                                       struct device_attribute *attr,
                                       const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (!(bond->params.miimon)) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Unable to set down delay as MII monitoring is disabled\n",
                       bond->dev->name);
                ret = -EPERM;
                goto out;
        }

        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no down delay value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if (new_value < 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Invalid down delay value %d not in range %d-%d; rejected.\n",
                       bond->dev->name, new_value, 1, INT_MAX);
                ret = -EINVAL;
                goto out;
        } else {
                if ((new_value % bond->params.miimon) != 0) {
                        printk(KERN_WARNING DRV_NAME
                               ": %s: Warning: down delay (%d) is not a multiple "
                               "of miimon (%d), delay rounded to %d ms\n",
                               bond->dev->name, new_value, bond->params.miimon,
                               (new_value / bond->params.miimon) *
                               bond->params.miimon);
                }
                bond->params.downdelay = new_value / bond->params.miimon;
                printk(KERN_INFO DRV_NAME ": %s: Setting down delay to %d.\n",
                       bond->dev->name, bond->params.downdelay * bond->params.miimon);

        }

out:
        return ret;
}
static DEVICE_ATTR(downdelay, S_IRUGO | S_IWUSR , bonding_show_downdelay, bonding_store_downdelay);

static ssize_t bonding_show_updelay(struct device *d,
                                    struct device_attribute *attr,
                                    char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.updelay * bond->params.miimon);

}

static ssize_t bonding_store_updelay(struct device *d,
                                     struct device_attribute *attr,
                                     const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (!(bond->params.miimon)) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Unable to set up delay as MII monitoring is disabled\n",
                       bond->dev->name);
                ret = -EPERM;
                goto out;
        }

        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no up delay value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if (new_value < 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Invalid down delay value %d not in range %d-%d; rejected.\n",
                       bond->dev->name, new_value, 1, INT_MAX);
                ret = -EINVAL;
                goto out;
        } else {
                if ((new_value % bond->params.miimon) != 0) {
                        printk(KERN_WARNING DRV_NAME
                               ": %s: Warning: up delay (%d) is not a multiple "
                               "of miimon (%d), updelay rounded to %d ms\n",
                               bond->dev->name, new_value, bond->params.miimon,
                               (new_value / bond->params.miimon) *
                               bond->params.miimon);
                }
                bond->params.updelay = new_value / bond->params.miimon;
                printk(KERN_INFO DRV_NAME ": %s: Setting up delay to %d.\n",
                       bond->dev->name, bond->params.updelay * bond->params.miimon);

        }

out:
        return ret;
}
static DEVICE_ATTR(updelay, S_IRUGO | S_IWUSR , bonding_show_updelay, bonding_store_updelay);

/*
 * Show and set the LACP interval.  Interface must be down, and the mode
 * must be set to 802.3ad mode.
 */
static ssize_t bonding_show_lacp(struct device *d,
                                 struct device_attribute *attr,
                                 char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%s %d\n",
                bond_lacp_tbl[bond->params.lacp_fast].modename,
                bond->params.lacp_fast);
}

static ssize_t bonding_store_lacp(struct device *d,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (bond->dev->flags & IFF_UP) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Unable to update LACP rate because interface is up.\n",
                       bond->dev->name);
                ret = -EPERM;
                goto out;
        }

        if (bond->params.mode != BOND_MODE_8023AD) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Unable to update LACP rate because bond is not in 802.3ad mode.\n",
                       bond->dev->name);
                ret = -EPERM;
                goto out;
        }

        new_value = bond_parse_parm(buf, bond_lacp_tbl);

        if ((new_value == 1) || (new_value == 0)) {
                bond->params.lacp_fast = new_value;
                printk(KERN_INFO DRV_NAME
                       ": %s: Setting LACP rate to %s (%d).\n",
                       bond->dev->name, bond_lacp_tbl[new_value].modename, new_value);
        } else {
                printk(KERN_ERR DRV_NAME
                       ": %s: Ignoring invalid LACP rate value %.*s.\n",
                        bond->dev->name, (int)strlen(buf) - 1, buf);
                ret = -EINVAL;
        }
out:
        return ret;
}
static DEVICE_ATTR(lacp_rate, S_IRUGO | S_IWUSR, bonding_show_lacp, bonding_store_lacp);

/*
 * Show and set the number of grat ARP to send after a failover event.
 */
static ssize_t bonding_show_n_grat_arp(struct device *d,
                                   struct device_attribute *attr,
                                   char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.num_grat_arp);
}

static ssize_t bonding_store_n_grat_arp(struct device *d,
                                    struct device_attribute *attr,
                                    const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no num_grat_arp value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if (new_value < 0 || new_value > 255) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Invalid num_grat_arp value %d not in range 0-255; rejected.\n",
                       bond->dev->name, new_value);
                ret = -EINVAL;
                goto out;
        } else {
                bond->params.num_grat_arp = new_value;
        }
out:
        return ret;
}
static DEVICE_ATTR(num_grat_arp, S_IRUGO | S_IWUSR, bonding_show_n_grat_arp, bonding_store_n_grat_arp);

/*
 * Show and set the number of unsolicted NA's to send after a failover event.
 */
static ssize_t bonding_show_n_unsol_na(struct device *d,
                                       struct device_attribute *attr,
                                       char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.num_unsol_na);
}

static ssize_t bonding_store_n_unsol_na(struct device *d,
                                        struct device_attribute *attr,
                                        const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no num_unsol_na value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if (new_value < 0 || new_value > 255) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Invalid num_unsol_na value %d not in range 0-255; rejected.\n",
                       bond->dev->name, new_value);
                ret = -EINVAL;
                goto out;
        } else {
                bond->params.num_unsol_na = new_value;
        }
out:
        return ret;
}
static DEVICE_ATTR(num_unsol_na, S_IRUGO | S_IWUSR, bonding_show_n_unsol_na, bonding_store_n_unsol_na);

/*
 * Show and set the MII monitor interval.  There are two tricky bits
 * here.  First, if MII monitoring is activated, then we must disable
 * ARP monitoring.  Second, if the timer isn't running, we must
 * start it.
 */
static ssize_t bonding_show_miimon(struct device *d,
                                   struct device_attribute *attr,
                                   char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.miimon);
}

static ssize_t bonding_store_miimon(struct device *d,
                                    struct device_attribute *attr,
                                    const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);

        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no miimon value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if (new_value < 0) {
                printk(KERN_ERR DRV_NAME
                       ": %s: Invalid miimon value %d not in range %d-%d; rejected.\n",
                       bond->dev->name, new_value, 1, INT_MAX);
                ret = -EINVAL;
                goto out;
        } else {
                printk(KERN_INFO DRV_NAME
                       ": %s: Setting MII monitoring interval to %d.\n",
                       bond->dev->name, new_value);
                bond->params.miimon = new_value;
                if(bond->params.updelay)
                        printk(KERN_INFO DRV_NAME
                              ": %s: Note: Updating updelay (to %d) "
                              "since it is a multiple of the miimon value.\n",
                              bond->dev->name,
                              bond->params.updelay * bond->params.miimon);
                if(bond->params.downdelay)
                        printk(KERN_INFO DRV_NAME
                              ": %s: Note: Updating downdelay (to %d) "
                              "since it is a multiple of the miimon value.\n",
                              bond->dev->name,
                              bond->params.downdelay * bond->params.miimon);
                if (bond->params.arp_interval) {
                        printk(KERN_INFO DRV_NAME
                               ": %s: MII monitoring cannot be used with "
                               "ARP monitoring. Disabling ARP monitoring...\n",
                               bond->dev->name);
                        bond->params.arp_interval = 0;
                        bond->dev->priv_flags &= ~IFF_MASTER_ARPMON;
                        if (bond->params.arp_validate) {
                                bond_unregister_arp(bond);
                                bond->params.arp_validate =
                                        BOND_ARP_VALIDATE_NONE;
                        }
                        if (delayed_work_pending(&bond->arp_work)) {
                                cancel_delayed_work(&bond->arp_work);
                                flush_workqueue(bond->wq);
                        }
                }

                if (bond->dev->flags & IFF_UP) {
                        /* If the interface is up, we may need to fire off
                         * the MII timer. If the interface is down, the
                         * timer will get fired off when the open function
                         * is called.
                         */
                        if (!delayed_work_pending(&bond->mii_work)) {
                                INIT_DELAYED_WORK(&bond->mii_work,
                                                  bond_mii_monitor);
                                queue_delayed_work(bond->wq,
                                                   &bond->mii_work, 0);
                        }
                }
        }
out:
        return ret;
}
static DEVICE_ATTR(miimon, S_IRUGO | S_IWUSR, bonding_show_miimon, bonding_store_miimon);

/*
 * Show and set the primary slave.  The store function is much
 * simpler than bonding_store_slaves function because it only needs to
 * handle one interface name.
 * The bond must be a mode that supports a primary for this be
 * set.
 */
static ssize_t bonding_show_primary(struct device *d,
                                    struct device_attribute *attr,
                                    char *buf)
{
        int count = 0;
        struct bonding *bond = to_bond(d);

        if (bond->primary_slave)
                count = sprintf(buf, "%s\n", bond->primary_slave->dev->name);

        return count;
}

static ssize_t bonding_store_primary(struct device *d,
                                     struct device_attribute *attr,
                                     const char *buf, size_t count)
{
        int i;
        struct slave *slave;
        struct bonding *bond = to_bond(d);

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

        if (!USES_PRIMARY(bond->params.mode)) {
                printk(KERN_INFO DRV_NAME
                       ": %s: Unable to set primary slave; %s is in mode %d\n",
                       bond->dev->name, bond->dev->name, bond->params.mode);
        } else {
                bond_for_each_slave(bond, slave, i) {
                        if (strnicmp
                            (slave->dev->name, buf,
                             strlen(slave->dev->name)) == 0) {
                                printk(KERN_INFO DRV_NAME
                                       ": %s: Setting %s as primary slave.\n",
                                       bond->dev->name, slave->dev->name);
                                bond->primary_slave = slave;
                                bond_select_active_slave(bond);
                                goto out;
                        }
                }

                /* if we got here, then we didn't match the name of any slave */

                if (strlen(buf) == 0 || buf[0] == '\n') {
                        printk(KERN_INFO DRV_NAME
                               ": %s: Setting primary slave to None.\n",
                               bond->dev->name);
                        bond->primary_slave = NULL;
                                bond_select_active_slave(bond);
                } else {
                        printk(KERN_INFO DRV_NAME
                               ": %s: Unable to set %.*s as primary slave as it is not a slave.\n",
                               bond->dev->name, (int)strlen(buf) - 1, buf);
                }
        }
out:
        write_unlock_bh(&bond->curr_slave_lock);
        read_unlock(&bond->lock);
        rtnl_unlock();

        return count;
}
static DEVICE_ATTR(primary, S_IRUGO | S_IWUSR, bonding_show_primary, bonding_store_primary);

/*
 * Show and set the use_carrier flag.
 */
static ssize_t bonding_show_carrier(struct device *d,
                                    struct device_attribute *attr,
                                    char *buf)
{
        struct bonding *bond = to_bond(d);

        return sprintf(buf, "%d\n", bond->params.use_carrier);
}

static ssize_t bonding_store_carrier(struct device *d,
                                     struct device_attribute *attr,
                                     const char *buf, size_t count)
{
        int new_value, ret = count;
        struct bonding *bond = to_bond(d);


        if (sscanf(buf, "%d", &new_value) != 1) {
                printk(KERN_ERR DRV_NAME
                       ": %s: no use_carrier value specified.\n",
                       bond->dev->name);
                ret = -EINVAL;
                goto out;
        }
        if ((new_value == 0) || (new_value == 1)) {
                bond->params.use_carrier = new_value;
                printk(KERN_INFO DRV_NAME ": %s: Setting use_carrier to %d.\n",
                       bond->dev->name, new_value);
        } else {
                printk(KERN_INFO DRV_NAME
                       ": %s: Ignoring invalid use_carrier value %d.\n",
                       bond->dev->name, new_value);
        }
out:
        return count;
}
static DEVICE_ATTR(use_carrier, S_IRUGO | S_IWUSR, bonding_show_carrier, bonding_store_carrier);


/*
 * Show and set currently active_slave.
 */
static ssize_t bonding_show_active_slave(struct device *d,
                                         struct device_attribute *attr,
                                         char *buf)
{
        struct slave *curr;
        struct bonding *bond = to_bond(d);
        int count = 0;

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

        if (USES_PRIMARY(bond->params.mode) && curr)
                count = sprintf(buf, "%s\n", curr->dev->name);
        return count;
}

static ssize_t bonding_store_active_slave(struct device *d,
                                          struct device_attribute *attr,
                                          const char *buf, size_t count)
{
        int i;
        struct slave *slave;
        struct slave *old_active = NULL;
        struct slave *new_active = NULL;
        struct bonding *bond = to_bond(d);

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

        if (!USES_PRIMARY(bond->params.mode)) {
                printk(KERN_INFO DRV_NAME
                       ": %s: Unable to change active slave; %s is in mode %d\n",
                       bond->dev->name, bond->dev->name, bond->params.mode);
        } else {
                bond_for_each_slave(bond, slave, i) {
                        if (strnicmp
                            (slave->dev->name, buf,
                             strlen(slave->dev->name)) == 0) {
                                old_active = bond->curr_active_slave;
                                new_active = slave;
                                if (new_active == old_active) {
                                        /* do nothing */
                                        printk(KERN_INFO DRV_NAME
                                               ": %s: %s is already the current active slave.\n",
                                               bond->dev->name, slave->dev->name);
                                        goto out;
                                }
                                else {
                                        if ((new_active) &&
                                            (old_active) &&
                                            (new_active->link == BOND_LINK_UP) &&
                                            IS_UP(new_active->dev)) {
                                                printk(KERN_INFO DRV_NAME
                                                      ": %s: Setting %s as active slave.\n",
                                                      bond->dev->name, slave->dev->name);
                                                bond_change_active_slave(bond, new_active);
                                        }
                                        else {
                                                printk(KERN_INFO DRV_NAME
                                                      ": %s: Could not set %s as active slave; "
                                                      "either %s is down or the link is down.\n",
                                                      bond->dev->name, slave->dev->name,
                                                      slave->dev->name);
                                        }
                                        goto out;
                                }
                        }
                }

                /* if we got here, then we didn't match the name of any slave */

                if (strlen(buf) == 0 || buf[0] == '\n') {
                        printk(KERN_INFO DRV_NAME
                               ": %s: Setting active slave to None.\n",
                               bond->dev->name);
                        bond->primary_slave = NULL;
                                bond_select_active_slave(bond);
                } else {
                        printk(KERN_INFO DRV_NAME
                               ": %s: Unable to set %.*s as active slave as it is not a slave.\n",
                               bond->dev->name, (int)strlen(buf) - 1, buf);
                }
        }
out:
        write_unlock_bh(&bond->curr_slave_lock);
        read_unlock(&bond->lock);
        rtnl_unlock();

        return count;

}
static DEVICE_ATTR(active_slave, S_IRUGO | S_IWUSR, bonding_show_active_slave, bonding_store_active_slave);


/*
 * Show link status of the bond interface.
 */
static ssize_t bonding_show_mii_status(struct device *d,
                                       struct device_attribute *attr,
                                       char *buf)
{
        struct slave *curr;
        struct bonding *bond = to_bond(d);

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

        return sprintf(buf, "%s\n", (curr) ? "up" : "down");
}
static DEVICE_ATTR(mii_status, S_IRUGO, bonding_show_mii_status, NULL);


/*
 * Show current 802.3ad aggregator ID.
 */
static ssize_t bonding_show_ad_aggregator(struct device *d,
                                          struct device_attribute *attr,
                                          char *buf)
{
        int count = 0;
        struct bonding *bond = to_bond(d);

        if (bond->params.mode == BOND_MODE_8023AD) {
                struct ad_info ad_info;
                count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.aggregator_id);
        }

        return count;
}
static DEVICE_ATTR(ad_aggregator, S_IRUGO, bonding_show_ad_aggregator, NULL);


/*
 * Show number of active 802.3ad ports.
 */
static ssize_t bonding_show_ad_num_ports(struct device *d,
                                         struct device_attribute *attr,
                                         char *buf)
{
        int count = 0;
        struct bonding *bond = to_bond(d);

        if (bond->params.mode == BOND_MODE_8023AD) {
                struct ad_info ad_info;
                count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0: ad_info.ports);
        }

        return count;
}
static DEVICE_ATTR(ad_num_ports, S_IRUGO, bonding_show_ad_num_ports, NULL);


/*
 * Show current 802.3ad actor key.
 */
static ssize_t bonding_show_ad_actor_key(struct device *d,
                                         struct device_attribute *attr,
                                         char *buf)
{
        int count = 0;
        struct bonding *bond = to_bond(d);

        if (bond->params.mode == BOND_MODE_8023AD) {
                struct ad_info ad_info;
                count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.actor_key);
        }

        return count;
}
static DEVICE_ATTR(ad_actor_key, S_IRUGO, bonding_show_ad_actor_key, NULL);


/*
 * Show current 802.3ad partner key.
 */
static ssize_t bonding_show_ad_partner_key(struct device *d,
                                           struct device_attribute *attr,
                                           char *buf)
{
        int count = 0;
        struct bonding *bond = to_bond(d);

        if (bond->params.mode == BOND_MODE_8023AD) {
                struct ad_info ad_info;
                count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.partner_key);
        }

        return count;
}
static DEVICE_ATTR(ad_partner_key, S_IRUGO, bonding_show_ad_partner_key, NULL);


/*
 * Show current 802.3ad partner mac.
 */
static ssize_t bonding_show_ad_partner_mac(struct device *d,
                                           struct device_attribute *attr,
                                           char *buf)
{
        int count = 0;
        struct bonding *bond = to_bond(d);

        if (bond->params.mode == BOND_MODE_8023AD) {
                struct ad_info ad_info;
                if (!bond_3ad_get_active_agg_info(bond, &ad_info)) {
                        count = sprintf(buf, "%pM\n", ad_info.partner_system);
                }
        }

        return count;
}
static DEVICE_ATTR(ad_partner_mac, S_IRUGO, bonding_show_ad_partner_mac, NULL);



static struct attribute *per_bond_attrs[] = {
        &dev_attr_slaves.attr,
        &dev_attr_mode.attr,
        &dev_attr_fail_over_mac.attr,
        &dev_attr_arp_validate.attr,
        &dev_attr_arp_interval.attr,
        &dev_attr_arp_ip_target.attr,
        &dev_attr_downdelay.attr,
        &dev_attr_updelay.attr,
        &dev_attr_lacp_rate.attr,
        &dev_attr_xmit_hash_policy.attr,
        &dev_attr_num_grat_arp.attr,
        &dev_attr_num_unsol_na.attr,
        &dev_attr_miimon.attr,
        &dev_attr_primary.attr,
        &dev_attr_use_carrier.attr,
        &dev_attr_active_slave.attr,
        &dev_attr_mii_status.attr,
        &dev_attr_ad_aggregator.attr,
        &dev_attr_ad_num_ports.attr,
        &dev_attr_ad_actor_key.attr,
        &dev_attr_ad_partner_key.attr,
        &dev_attr_ad_partner_mac.attr,
        NULL,
};

static struct attribute_group bonding_group = {
        .name = "bonding",
        .attrs = per_bond_attrs,
};

/*
 * Initialize sysfs.  This sets up the bonding_masters file in
 * /sys/class/net.
 */
int bond_create_sysfs(void)
{
        int ret;

        ret = netdev_class_create_file(&class_attr_bonding_masters);
        /*
         * Permit multiple loads of the module by ignoring failures to
         * create the bonding_masters sysfs file.  Bonding devices
         * created by second or subsequent loads of the module will
         * not be listed in, or controllable by, bonding_masters, but
         * will have the usual "bonding" sysfs directory.
         *
         * This is done to preserve backwards compatibility for
         * initscripts/sysconfig, which load bonding multiple times to
         * configure multiple bonding devices.
         */
        if (ret == -EEXIST) {
                /* Is someone being kinky and naming a device bonding_master? */
                if (__dev_get_by_name(&init_net,
                                      class_attr_bonding_masters.attr.name))
                        printk(KERN_ERR
                               "network device named %s already exists in sysfs",
                               class_attr_bonding_masters.attr.name);
        }

        return ret;

}

/*
 * Remove /sys/class/net/bonding_masters.
 */
void bond_destroy_sysfs(void)
{
        netdev_class_remove_file(&class_attr_bonding_masters);
}

/*
 * Initialize sysfs for each bond.  This sets up and registers
 * the 'bondctl' directory for each individual bond under /sys/class/net.
 */
int bond_create_sysfs_entry(struct bonding *bond)
{
        struct net_device *dev = bond->dev;
        int err;

        err = sysfs_create_group(&(dev->dev.kobj), &bonding_group);
        if (err) {
                printk(KERN_EMERG "eek! didn't create group!\n");
        }

        if (expected_refcount < 1)
                expected_refcount = atomic_read(&bond->dev->dev.kobj.kref.refcount);

        return err;
}
/*
 * Remove sysfs entries for each bond.
 */
void bond_destroy_sysfs_entry(struct bonding *bond)
{
        struct net_device *dev = bond->dev;

        sysfs_remove_group(&(dev->dev.kobj), &bonding_group);
}