/*
 * 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.
 *
 * v0.1 - first working version.
 * v0.2 - changed stats to be calculated by summing slaves stats.
 *
 * Changes:
 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 * - fix leaks on failure at bond_init
 *
 * 2000/09/30 - Willy Tarreau <willy at meta-x.org>
 *     - added trivial code to release a slave device.
 *     - fixed security bug (CAP_NET_ADMIN not checked)
 *     - implemented MII link monitoring to disable dead links :
 *       All MII capable slaves are checked every <miimon> milliseconds
 *       (100 ms seems good). This value can be changed by passing it to
 *       insmod. A value of zero disables the monitoring (default).
 *     - fixed an infinite loop in bond_xmit_roundrobin() when there's no
 *       good slave.
 *     - made the code hopefully SMP safe
 *
 * 2000/10/03 - Willy Tarreau <willy at meta-x.org>
 *     - optimized slave lists based on relevant suggestions from Thomas Davis
 *     - implemented active-backup method to obtain HA with two switches:
 *       stay as long as possible on the same active interface, while we
 *       also monitor the backup one (MII link status) because we want to know
 *       if we are able to switch at any time. ( pass "mode=1" to insmod )
 *     - lots of stress testings because we need it to be more robust than the
 *       wires ! :->
 *
 * 2000/10/09 - Willy Tarreau <willy at meta-x.org>
 *     - added up and down delays after link state change.
 *     - optimized the slaves chaining so that when we run forward, we never
 *       repass through the bond itself, but we can find it by searching
 *       backwards. Renders the deletion more difficult, but accelerates the
 *       scan.
 *     - smarter enslaving and releasing.
 *     - finer and more robust SMP locking
 *
 * 2000/10/17 - Willy Tarreau <willy at meta-x.org>
 *     - fixed two potential SMP race conditions
 *
 * 2000/10/18 - Willy Tarreau <willy at meta-x.org>
 *     - small fixes to the monitoring FSM in case of zero delays
 * 2000/11/01 - Willy Tarreau <willy at meta-x.org>
 *     - fixed first slave not automatically used in trunk mode.
 * 2000/11/10 : spelling of "EtherChannel" corrected.
 * 2000/11/13 : fixed a race condition in case of concurrent accesses to ioctl().
 * 2000/12/16 : fixed improper usage of rtnl_exlock_nowait().
 *
 * 2001/1/3 - Chad N. Tindel <ctindel at ieee dot org>
 *     - The bonding driver now simulates MII status monitoring, just like
 *       a normal network device.  It will show that the link is down iff
 *       every slave in the bond shows that their links are down.  If at least
 *       one slave is up, the bond's MII status will appear as up.
 *
 * 2001/2/7 - Chad N. Tindel <ctindel at ieee dot org>
 *     - Applications can now query the bond from user space to get
 *       information which may be useful.  They do this by calling
 *       the BOND_INFO_QUERY ioctl.  Once the app knows how many slaves
 *       are in the bond, it can call the BOND_SLAVE_INFO_QUERY ioctl to
 *       get slave specific information (# link failures, etc).  See
 *       <linux/if_bonding.h> for more details.  The structs of interest
 *       are ifbond and ifslave.
 *
 * 2001/4/5 - Chad N. Tindel <ctindel at ieee dot org>
 *     - Ported to 2.4 Kernel
 * 
 * 2001/5/2 - Jeffrey E. Mast <jeff at mastfamily dot com>
 *     - When a device is detached from a bond, the slave device is no longer
 *       left thinking that is has a master.
 *
 * 2001/5/16 - Jeffrey E. Mast <jeff at mastfamily dot com>
 *     - memset did not appropriately initialized the bond rw_locks. Used 
 *       rwlock_init to initialize to unlocked state to prevent deadlock when 
 *       first attempting a lock
 *     - Called SET_MODULE_OWNER for bond device
 *
 * 2001/5/17 - Tim Anderson <tsa at mvista.com>
 *     - 2 paths for releasing for slave release; 1 through ioctl
 *       and 2) through close. Both paths need to release the same way.
 *     - the free slave in bond release is changing slave status before
 *       the free. The netdev_set_master() is intended to change slave state
 *       so it should not be done as part of the release process.
 *     - Simple rule for slave state at release: only the active in A/B and
 *       only one in the trunked case.
 *
 * 2001/6/01 - Tim Anderson <tsa at mvista.com>
 *     - Now call dev_close when releasing a slave so it doesn't screw up
 *       out routing table.
 *
 * 2001/6/01 - Chad N. Tindel <ctindel at ieee dot org>
 *     - Added /proc support for getting bond and slave information.
 *       Information is in /proc/net/<bond device>/info. 
 *     - Changed the locking when calling bond_close to prevent deadlock.
 *
 * 2001/8/05 - Janice Girouard <girouard at us.ibm.com>
 *     - correct problem where refcnt of slave is not incremented in bond_ioctl
 *       so the system hangs when halting.
 *     - correct locking problem when unable to malloc in bond_enslave.
 *     - adding bond_xmit_xor logic.
 *     - adding multiple bond device support.
 *
 * 2001/8/13 - Erik Habbinga <erik_habbinga at hp dot com>
 *     - correct locking problem with rtnl_exlock_nowait
 *
 * 2001/8/23 - Janice Girouard <girouard at us.ibm.com>
 *     - bzero initial dev_bonds, to correct oops
 *     - convert SIOCDEVPRIVATE to new MII ioctl calls
 *
 * 2001/9/13 - Takao Indoh <indou dot takao at jp dot fujitsu dot com>
 *     - Add the BOND_CHANGE_ACTIVE ioctl implementation
 *
 * 2001/9/14 - Mark Huth <mhuth at mvista dot com>
 *     - Change MII_LINK_READY to not check for end of auto-negotiation,
 *       but only for an up link.
 *
 * 2001/9/20 - Chad N. Tindel <ctindel at ieee dot org>
 *     - Add the device field to bonding_t.  Previously the net_device 
 *       corresponding to a bond wasn't available from the bonding_t 
 *       structure.
 *
 * 2001/9/25 - Janice Girouard <girouard at us.ibm.com>
 *     - add arp_monitor for active backup mode
 *
 * 2001/10/23 - Takao Indoh <indou dot takao at jp dot fujitsu dot com>
 *     - Various memory leak fixes
 *
 * 2001/11/5 - Mark Huth <mark dot huth at mvista dot com>
 *     - Don't take rtnl lock in bond_mii_monitor as it deadlocks under 
 *       certain hotswap conditions.  
 *       Note:  this same change may be required in bond_arp_monitor ???
 *     - Remove possibility of calling bond_sethwaddr with NULL slave_dev ptr 
 *     - Handle hot swap ethernet interface deregistration events to remove
 *       kernel oops following hot swap of enslaved interface
 *
 * 2002/1/2 - Chad N. Tindel <ctindel at ieee dot org>
 *     - Restore original slave flags at release time.
 *
 * 2002/02/18 - Erik Habbinga <erik_habbinga at hp dot com>
 *     - bond_release(): calling kfree on our_slave after call to
 *       bond_restore_slave_flags, not before
 *     - bond_enslave(): saving slave flags into original_flags before
 *       call to netdev_set_master, so the IFF_SLAVE flag doesn't end
 *       up in original_flags
 *
 * 2002/04/05 - Mark Smith <mark.smith at comdev dot cc> and
 *              Steve Mead <steve.mead at comdev dot cc>
 *     - Port Gleb Natapov's multicast support patchs from 2.4.12
 *       to 2.4.18 adding support for multicast.
 *
 * 2002/06/17 - Tony Cureington <tony.cureington * hp_com>
 *     - corrected uninitialized pointer (ifr.ifr_data) in bond_check_dev_link;
 *       actually changed function to use ETHTOOL, then MIIPHY, and finally
 *       MIIREG to determine the link status
 *     - fixed bad ifr_data pointer assignments in bond_ioctl
 *     - corrected mode 1 being reported as active-backup in bond_get_info;
 *       also added text to distinguish type of load balancing (rr or xor)
 *     - change arp_ip_target module param from "1-12s" (array of 12 ptrs)
 *       to "s" (a single ptr)
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/socket.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>
#include <linux/errno.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/rtnetlink.h>

#include <linux/if_bonding.h>
#include <linux/smp.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/mii.h>
#include <linux/ethtool.h>


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

#undef  MII_LINK_UP
#define MII_LINK_UP     0x04

#undef  MII_ENDOF_NWAY
#define MII_ENDOF_NWAY  0x20

#undef  MII_LINK_READY
#define MII_LINK_READY  (MII_LINK_UP)

#ifndef BOND_LINK_ARP_INTERV
#define BOND_LINK_ARP_INTERV    0
#endif

static int arp_interval = BOND_LINK_ARP_INTERV;
static char *arp_ip_target = NULL;
static unsigned long arp_target = 0;
static u32 my_ip = 0;
char *arp_target_hw_addr = NULL;

static int max_bonds    = BOND_DEFAULT_MAX_BONDS;
static int miimon       = BOND_LINK_MON_INTERV;
static int mode         = BOND_MODE_ROUNDROBIN;
static int updelay      = 0;
static int downdelay    = 0;

static int first_pass   = 1;
int bond_cnt;
static struct bonding *these_bonds =  NULL;
static struct net_device *dev_bonds = NULL;

MODULE_PARM(max_bonds, "i");
MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
MODULE_PARM(miimon, "i");
MODULE_PARM_DESC(miimon, "Link check interval in milliseconds");
MODULE_PARM(mode, "i");
MODULE_PARM(arp_interval, "i");
MODULE_PARM_DESC(arp_interval, "arp interval in milliseconds");
MODULE_PARM(arp_ip_target, "s");
MODULE_PARM_DESC(arp_ip_target, "arp target in n.n.n.n form");
MODULE_PARM_DESC(mode, "Mode of operation : 0 for round robin, 1 for active-backup, 2 for xor");
MODULE_PARM(updelay, "i");
MODULE_PARM_DESC(updelay, "Delay before considering link up, in milliseconds");
MODULE_PARM(downdelay, "i");
MODULE_PARM_DESC(downdelay, "Delay before considering link down, in milliseconds");

extern void arp_send( int type, int ptype, u32 dest_ip, struct net_device *dev,
        u32 src_ip, unsigned char *dest_hw, unsigned char *src_hw, 
        unsigned char *target_hw);

static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *dev);
static int bond_xmit_xor(struct sk_buff *skb, struct net_device *dev);
static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *dev);
static struct net_device_stats *bond_get_stats(struct net_device *dev);
static void bond_mii_monitor(struct net_device *dev);
static void bond_arp_monitor(struct net_device *dev);
static int bond_event(struct notifier_block *this, unsigned long event, void *ptr);
static void bond_restore_slave_flags(slave_t *slave);
static void bond_mc_list_destroy(struct bonding *bond);
static void bond_mc_add(bonding_t *bond, void *addr, int alen);
static void bond_mc_delete(bonding_t *bond, void *addr, int alen);
static int bond_mc_list_copy (struct dev_mc_list *src, struct bonding *dst, int gpf_flag);
static inline int dmi_same(struct dev_mc_list *dmi1, struct dev_mc_list *dmi2);
static void bond_set_promiscuity(bonding_t *bond, int inc);
static void bond_set_allmulti(bonding_t *bond, int inc);
static struct dev_mc_list* bond_mc_list_find_dmi(struct dev_mc_list *dmi, struct dev_mc_list *mc_list);
static void bond_set_slave_inactive_flags(slave_t *slave);
static void bond_set_slave_active_flags(slave_t *slave);
static int bond_enslave(struct net_device *master, struct net_device *slave);
static int bond_release(struct net_device *master, struct net_device *slave);
static int bond_release_all(struct net_device *master);
static int bond_sethwaddr(struct net_device *master, struct net_device *slave);

/*
 * bond_get_info is the interface into the /proc filesystem.  This is
 * a different interface than the BOND_INFO_QUERY ioctl.  That is done
 * through the generic networking ioctl interface, and bond_info_query
 * is the internal function which provides that information.
 */
static int bond_get_info(char *buf, char **start, off_t offset, int length);

/* #define BONDING_DEBUG 1 */

/* several macros */

#define IS_UP(dev)      ((((dev)->flags & (IFF_UP)) == (IFF_UP)) && \
                        (netif_running(dev) && netif_carrier_ok(dev)))

static void bond_restore_slave_flags(slave_t *slave)
{
        slave->dev->flags = slave->original_flags;
}

static void bond_set_slave_inactive_flags(slave_t *slave)
{
        slave->state = BOND_STATE_BACKUP;
        slave->dev->flags |= IFF_NOARP;
}

static void bond_set_slave_active_flags(slave_t *slave)
{
        slave->state = BOND_STATE_ACTIVE;
        slave->dev->flags &= ~IFF_NOARP;
}

/* 
 * This function detaches the slave <slave> from the list <bond>.
 * WARNING: no check is made to verify if the slave effectively
 * belongs to <bond>. It returns <slave> in case it's needed.
 * Nothing is freed on return, structures are just unchained.
 * If the bond->current_slave pointer was pointing to <slave>,
 * it's replaced with slave->next, or <bond> if not applicable.
 */
static slave_t *bond_detach_slave(bonding_t *bond, slave_t *slave)
{
        if ((bond == NULL) || (slave == NULL) ||
           ((void *)bond == (void *)slave)) {
                printk(KERN_ERR
                        "bond_detach_slave(): trying to detach "
                        "slave %p from bond %p\n", bond, slave);
                return slave;
        }

        if (bond->next == slave) {  /* is the slave at the head ? */
                if (bond->prev == slave) {  /* is the slave alone ? */
                        write_lock(&bond->ptrlock);
                        bond->current_slave = NULL; /* no slave anymore */
                        write_unlock(&bond->ptrlock);
                        bond->prev = bond->next = (slave_t *)bond;
                } else { /* not alone */
                        bond->next        = slave->next;
                        slave->next->prev = (slave_t *)bond;
                        bond->prev->next  = slave->next;

                        write_lock(&bond->ptrlock);
                        if (bond->current_slave == slave) {
                                bond->current_slave = slave->next;
                        }
                        write_unlock(&bond->ptrlock);
                }
        }
        else {
                slave->prev->next = slave->next;
                if (bond->prev == slave) {  /* is this slave the last one ? */
                        bond->prev = slave->prev;
                } else {
                        slave->next->prev = slave->prev;
                }

                write_lock(&bond->ptrlock);
                if (bond->current_slave == slave) {
                        bond->current_slave = slave->next;
                }
                write_unlock(&bond->ptrlock);
        }

        return slave;
}

/* 
 * if <dev> supports MII link status reporting, check its link
 * and report it as a bit field in a short int :
 *   - 0x04 means link is up,
 *   - 0x20 means end of autonegociation
 * If the device doesn't support MII, then we only report 0x24,
 * meaning that the link is up and running since we can't check it.
 */
static u16 bond_check_dev_link(struct net_device *dev)
{
        static int (* ioctl)(struct net_device *, struct ifreq *, int);
        struct ifreq ifr;
        struct mii_ioctl_data *mii;
        struct ethtool_value etool;

        if ((ioctl = dev->do_ioctl) != NULL)  { /* ioctl to access MII */
                /* 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.                                           */

                /* try SOICETHTOOL ioctl, some drivers cache ETHTOOL_GLINK */
                /* for a period of time; we need to encourage link status  */
                /* be reported by network drivers in real time; if the     */
                /* value is cached, the mmimon module parm may have no     */
                /* effect...                                               */
                etool.cmd = ETHTOOL_GLINK;
                ifr.ifr_data = (char*)&etool;
                if (ioctl(dev, &ifr, SIOCETHTOOL) == 0) {
                        if (etool.data == 1) {
                                return(MII_LINK_READY);
                        } 
                        else { 
                                return(0);
                        } 
                }

                /*
                 * We cannot assume that SIOCGMIIPHY will also read a
                 * register; not all network drivers support that.
                 */

                /* Yes, the mii is overlaid on the ifreq.ifr_ifru */
                mii = (struct mii_ioctl_data *)&ifr.ifr_data;
                if (ioctl(dev, &ifr, SIOCGMIIPHY) != 0) {
                        return MII_LINK_READY;   /* can't tell */
                }

                mii->reg_num = 1;
                if (ioctl(dev, &ifr, SIOCGMIIREG) == 0) {
                        /*
                         * mii->val_out contains MII reg 1, BMSR
                         * 0x0004 means link established
                         */
                        return mii->val_out;
                }

        }
        return MII_LINK_READY;  /* spoof link up ( we can't check it) */
}

static u16 bond_check_mii_link(bonding_t *bond)
{
        int has_active_interface = 0;
        unsigned long flags;

        read_lock_irqsave(&bond->lock, flags);
        read_lock(&bond->ptrlock);
        has_active_interface = (bond->current_slave != NULL);
        read_unlock(&bond->ptrlock);
        read_unlock_irqrestore(&bond->lock, flags);

        return (has_active_interface ? MII_LINK_READY : 0);
}

static int bond_open(struct net_device *dev)
{
        struct timer_list *timer = &((struct bonding *)(dev->priv))->mii_timer;
        struct timer_list *arp_timer = &((struct bonding *)(dev->priv))->arp_timer;
        MOD_INC_USE_COUNT;

        if (miimon > 0) {  /* link check interval, in milliseconds. */
                init_timer(timer);
                timer->expires  = jiffies + (miimon * HZ / 1000);
                timer->data     = (unsigned long)dev;
                timer->function = (void *)&bond_mii_monitor;
                add_timer(timer);
        }

        if (arp_interval> 0) {  /* arp interval, in milliseconds. */
                init_timer(arp_timer);
                arp_timer->expires  = jiffies + (arp_interval * HZ / 1000);
                arp_timer->data     = (unsigned long)dev;
                arp_timer->function = (void *)&bond_arp_monitor;
                add_timer(arp_timer);
        }
        return 0;
}

static int bond_close(struct net_device *master)
{
        bonding_t *bond = (struct bonding *) master->priv;
        unsigned long flags;

        write_lock_irqsave(&bond->lock, flags);

        if (miimon > 0) {  /* link check interval, in milliseconds. */
                del_timer(&bond->mii_timer);
        }
        if (arp_interval> 0) {  /* arp interval, in milliseconds. */
                del_timer(&bond->arp_timer);
        }

        /* Release the bonded slaves */
        bond_release_all(master);
        bond_mc_list_destroy (bond);

        write_unlock_irqrestore(&bond->lock, flags);

        MOD_DEC_USE_COUNT;
        return 0;
}

/* 
 * flush all members of flush->mc_list from device dev->mc_list
 */
static void bond_mc_list_flush(struct net_device *dev, struct net_device *flush)
{ 
        struct dev_mc_list *dmi; 
 
        for (dmi = flush->mc_list; dmi != NULL; dmi = dmi->next) 
                dev_mc_delete(dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
}

/*
 * 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; 
        }
}

/*
 * Add a Multicast address to every slave in the bonding group
 */
static void bond_mc_add(bonding_t *bond, void *addr, int alen)
{ 
        slave_t *slave;

        for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev) {
                dev_mc_add(slave->dev, addr, alen, 0);
        }
} 

/*
 * Remove a multicast address from every slave in the bonding group
 */
static void bond_mc_delete(bonding_t *bond, void *addr, int alen)
{ 
        slave_t *slave; 

        for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                dev_mc_delete(slave->dev, addr, alen, 0);
} 

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

        for (dmi = src; dmi != NULL; dmi = dmi->next) { 
                new_dmi = kmalloc(sizeof(struct dev_mc_list), gpf_flag);

                if (new_dmi == NULL) {
                        return -ENOMEM; 
                }

                new_dmi->next = dst->mc_list; 
                dst->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;
}

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

/*
 * Push the promiscuity flag down to all slaves
 */
static void bond_set_promiscuity(bonding_t *bond, int inc)
{ 
        slave_t *slave; 
 
        for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                dev_set_promiscuity(slave->dev, inc);
} 

/*
 * Push the allmulti flag down to all slaves
 */
static void bond_set_allmulti(bonding_t *bond, int inc)
{ 
        slave_t *slave; 
 
        for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                dev_set_allmulti(slave->dev, inc);
} 

/* 
 * 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 != NULL; idmi = idmi->next) {
                if (dmi_same(dmi, idmi)) {
                        return idmi; 
                }
        }
        return NULL;
} 

static void set_multicast_list(struct net_device *master)
{
        bonding_t *bond = master->priv;
        struct dev_mc_list *dmi;
        unsigned long flags = 0;

        /*
         * Lock the private data for the master
         */
        write_lock_irqsave(&bond->lock, flags);

        /* set promiscuity flag to slaves */
        if ( (master->flags & IFF_PROMISC) && !(bond->flags & IFF_PROMISC) )
                bond_set_promiscuity(bond, 1); 

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

        /* set allmulti flag to slaves */ 
        if ( (master->flags & IFF_ALLMULTI) && !(bond->flags & IFF_ALLMULTI) ) 
                bond_set_allmulti(bond, 1); 

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

        bond->flags = master->flags; 

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

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


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

        write_unlock_irqrestore(&bond->lock, flags);
}

/*
 * This function counts the number of attached 
 * slaves for use by bond_xmit_xor.
 */
static void update_slave_cnt(bonding_t *bond)
{
        slave_t *slave = NULL;

        bond->slave_cnt = 0;
        for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev) {
                bond->slave_cnt++;
        }
}

/* enslave device <slave> to bond device <master> */
static int bond_enslave(struct net_device *master_dev, 
                        struct net_device *slave_dev)
{
        bonding_t *bond = NULL;
        slave_t *new_slave = NULL;
        unsigned long flags = 0;
        int ndx = 0;
        int err = 0;
        struct dev_mc_list *dmi;

        if (master_dev == NULL || slave_dev == NULL) {
                return -ENODEV;
        }
        bond = (struct bonding *) master_dev->priv;

        if (slave_dev->do_ioctl == NULL) {
                printk(KERN_DEBUG
                        "Warning : no link monitoring support for %s\n",
                        slave_dev->name);
        }
        write_lock_irqsave(&bond->lock, flags);

        /* not running. */
        if ((slave_dev->flags & IFF_UP) != IFF_UP) {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Error, slave_dev is not running\n");
#endif
                write_unlock_irqrestore(&bond->lock, flags);
                return -EINVAL;
        }

        /* already enslaved */
        if (master_dev->flags & IFF_SLAVE || slave_dev->flags & IFF_SLAVE) {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Error, Device was already enslaved\n");
#endif
                write_unlock_irqrestore(&bond->lock, flags);
                return -EBUSY;
        }
                   
        if ((new_slave = kmalloc(sizeof(slave_t), GFP_KERNEL)) == NULL) {
                write_unlock_irqrestore(&bond->lock, flags);
                return -ENOMEM;
        }
        memset(new_slave, 0, sizeof(slave_t));

        /* save flags before call to netdev_set_master */
        new_slave->original_flags = slave_dev->flags;
        err = netdev_set_master(slave_dev, master_dev);

        if (err) {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Error %d calling netdev_set_master\n", err);
#endif
                kfree(new_slave);
                write_unlock_irqrestore(&bond->lock, flags);
                return err;      
        }

        new_slave->dev = slave_dev;

        /* set promiscuity level to new slave */ 
        if (master_dev->flags & IFF_PROMISC)
                dev_set_promiscuity(slave_dev, 1); 
 
        /* set allmulti level to new slave */
        if (master_dev->flags & IFF_ALLMULTI) 
                dev_set_allmulti(slave_dev, 1); 
 
        /* upload master's mc_list to new slave */ 
        for (dmi = master_dev->mc_list; dmi != NULL; dmi = dmi->next) 
                dev_mc_add (slave_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);

        /* 
         * queue to the end of the slaves list, make the first element its
         * successor, the last one its predecessor, and make it the bond's
         * predecessor. 
         *
         * Just to clarify, so future bonding driver hackers don't go through
         * the same confusion stage I did trying to figure this out, the
         * slaves are stored in a double linked circular list, sortof.
         * In the ->next direction, the last slave points to the first slave,
         * bypassing bond; only the slaves are in the ->next direction.
         * In the ->prev direction, however, the first slave points to bond
         * and bond points to the last slave.
         *
         * It looks like a circle with a little bubble hanging off one side
         * in the ->prev direction only.
         *
         * When going through the list once, its best to start at bond->prev
         * and go in the ->prev direction, testing for bond.  Doing this
         * in the ->next direction doesn't work.  Trust me, I know this now.
         * :)  -mts 2002.03.14
         */
        new_slave->prev       = bond->prev;
        new_slave->prev->next = new_slave;
        bond->prev            = new_slave;
        new_slave->next       = bond->next;

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

        /* check for initial state */
        if ((miimon <= 0) || ((bond_check_dev_link(slave_dev) & MII_LINK_READY)
                 == MII_LINK_READY)) {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Initial state of slave_dev is BOND_LINK_UP\n");
#endif
                new_slave->link  = BOND_LINK_UP;
        }
        else {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Initial state of slave_dev is BOND_LINK_DOWN\n");
#endif
                new_slave->link  = BOND_LINK_DOWN;
        }

        /* if we're in active-backup mode, we need one and only one active
         * interface. The backup interfaces will have their NOARP flag set
         * because we need them to be completely deaf and not to respond to
         * any ARP request on the network to avoid fooling a switch. Thus,
         * since we guarantee that current_slave always point to the last
         * usable interface, we just have to verify this interface's flag.
         */
        if (mode == BOND_MODE_ACTIVEBACKUP) {
                if (((bond->current_slave == NULL)
                        || (bond->current_slave->dev->flags & IFF_NOARP))
                        && (new_slave->link == BOND_LINK_UP)) {
#ifdef BONDING_DEBUG
                        printk(KERN_CRIT "This is the first active slave\n");
#endif
                        /* first slave or no active slave yet, and this link
                           is OK, so make this interface the active one */
                        bond->current_slave = new_slave;
                        bond_set_slave_active_flags(new_slave);
                }
                else {
#ifdef BONDING_DEBUG
                        printk(KERN_CRIT "This is just a backup slave\n");
#endif
                        bond_set_slave_inactive_flags(new_slave);
                }
        } else {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "This slave is always active in trunk mode\n");
#endif
                /* always active in trunk mode */
                new_slave->state = BOND_STATE_ACTIVE;
                if (bond->current_slave == NULL) {
                        bond->current_slave = new_slave;
                }
        }

        update_slave_cnt(bond);

        write_unlock_irqrestore(&bond->lock, flags);

        /*
         * !!! This is to support old versions of ifenslave.  We can remove
         * this in 2.5 because our ifenslave takes care of this for us.
         * We check to see if the master has a mac address yet.  If not,
         * we'll give it the mac address of our slave device.
         */
        for (ndx = 0; ndx < slave_dev->addr_len; ndx++) {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Checking ndx=%d of master_dev->dev_addr\n",
                       ndx);
#endif
                if (master_dev->dev_addr[ndx] != 0) {
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "Found non-zero byte at ndx=%d\n",
                       ndx);
#endif
                        break;
                }
        }
        if (ndx == slave_dev->addr_len) {
                /*
                 * We got all the way through the address and it was
                 * all 0's.
                 */
#ifdef BONDING_DEBUG
                printk(KERN_CRIT "%s doesn't have a MAC address yet.  ",
                       master_dev->name);
                printk(KERN_CRIT "Going to give assign it from %s.\n",
                       slave_dev->name);
#endif
                bond_sethwaddr(master_dev, slave_dev);
        }

        printk (KERN_INFO "%s: enslaving %s as a%s interface with a%s link.\n",
                master_dev->name, slave_dev->name,
                new_slave->state == BOND_STATE_ACTIVE ? "n active" : " backup",
                new_slave->link == BOND_LINK_UP ? "n up" : " down");

        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 fuction does nothing.
 * In the other cases, currnt_slave pointer is changed and 0 is returned.
 */
static int bond_change_active(struct net_device *master_dev, struct net_device *slave_dev)
{
        bonding_t *bond;
        slave_t *slave;
        slave_t *oldactive = NULL;
        slave_t *newactive = NULL;
        unsigned long flags;
        int ret = 0;

        if (master_dev == NULL || slave_dev == NULL) {
                return -ENODEV;
        }

        bond = (struct bonding *) master_dev->priv;
        write_lock_irqsave(&bond->lock, flags);
        slave = (slave_t *)bond;
        oldactive = bond->current_slave;

        while ((slave = slave->prev) != (slave_t *)bond) {
                if(slave_dev == slave->dev) {
                        newactive = slave;
                        break;
                }
        }

        if ((newactive != NULL)&&
            (oldactive != NULL)&&
            (newactive != oldactive)&&
            (newactive->link == BOND_LINK_UP)&&
            IS_UP(newactive->dev)) {
                bond_set_slave_inactive_flags(oldactive);
                bond_set_slave_active_flags(newactive);
                bond->current_slave = newactive;
                printk("%s : activate %s(old : %s)\n",
                        master_dev->name, newactive->dev->name, 
                        oldactive->dev->name);
        }
        else {
                ret = -EINVAL;
        }
        write_unlock_irqrestore(&bond->lock, flags);
        return ret;
}

/* Choose a new valid interface from the pool, set it active
 * and make it the current slave. If no valid interface is
 * found, the oldest slave in BACK state is choosen and
 * activated. If none is found, it's considered as no
 * interfaces left so the current slave is set to NULL.
 * The result is a pointer to the current slave.
 *
 * Since this function sends messages tails through printk, the caller
 * must have started something like `printk(KERN_INFO "xxxx ");'.
 *
 * Warning: must put locks around the call to this function if needed.
 */
slave_t *change_active_interface(bonding_t *bond)
{
        slave_t *newslave, *oldslave;
        slave_t *bestslave = NULL;
        int mintime;

        read_lock(&bond->ptrlock);
        newslave = oldslave = bond->current_slave;
        read_unlock(&bond->ptrlock);

        if (newslave == NULL) { /* there were no active slaves left */
                if (bond->next != (slave_t *)bond) {  /* found one slave */
                        write_lock(&bond->ptrlock);
                        newslave = bond->current_slave = bond->next;
                        write_unlock(&bond->ptrlock);
                } else {
                        printk (" but could not find any %s interface.\n",
                                (mode == BOND_MODE_ACTIVEBACKUP) ? "backup":"other");
                        write_lock(&bond->ptrlock);
                        bond->current_slave = (slave_t *)NULL;
                        write_unlock(&bond->ptrlock);
                        return NULL; /* still no slave, return NULL */
                }
        }

        mintime = updelay;

        do {
                if (IS_UP(newslave->dev)) {
                        if (newslave->link == BOND_LINK_UP) {
                                /* this one is immediately usable */
                                if (mode == BOND_MODE_ACTIVEBACKUP) {
                                        bond_set_slave_active_flags(newslave);
                                        printk (" and making interface %s the active one.\n",
                                                newslave->dev->name);
                                }
                                else {
                                        printk (" and setting pointer to interface %s.\n",
                                                newslave->dev->name);

                                }

                                write_lock(&bond->ptrlock);
                                bond->current_slave = newslave;
                                write_unlock(&bond->ptrlock);
                                return newslave;
                        }
                        else if (newslave->link == BOND_LINK_BACK) {
                                /* link up, but waiting for stabilization */
                                if (newslave->delay < mintime) {
                                        mintime = newslave->delay;
                                        bestslave = newslave;
                                }
                        }
                }
        } while ((newslave = newslave->next) != oldslave);

        /* no usable backup found, we'll see if we at least got a link that was
           coming back for a long time, and could possibly already be usable.
        */

        if (bestslave != NULL) {
                /* early take-over. */
                printk (" and making interface %s the active one %d ms earlier.\n",
                        bestslave->dev->name,
                        (updelay - bestslave->delay)*miimon);

                bestslave->delay = 0;
                bestslave->link = BOND_LINK_UP;
                bond_set_slave_active_flags(bestslave);

                write_lock(&bond->ptrlock);
                bond->current_slave = bestslave;
                write_unlock(&bond->ptrlock);
                return bestslave;
        }

        printk (" but could not find any %s interface.\n",
                (mode == BOND_MODE_ACTIVEBACKUP) ? "backup":"other");
        
        /* absolutely nothing found. let's return NULL */
        write_lock(&bond->ptrlock);
        bond->current_slave = (slave_t *)NULL;
        write_unlock(&bond->ptrlock);
        return NULL;
}

/*
 * Try to release the slave device <slave> from the bond device <master>
 * It is legal to access current_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.
 */
static int bond_release(struct net_device *master, struct net_device *slave)
{
        bonding_t *bond;
        slave_t *our_slave, *old_current;
        unsigned long flags;
        
        if (master == NULL || slave == NULL)  {
                return -ENODEV;
        }

        bond = (struct bonding *) master->priv;

        write_lock_irqsave(&bond->lock, flags);

        /* master already enslaved, or slave not enslaved,
           or no slave for this master */
        if ((master->flags & IFF_SLAVE) || !(slave->flags & IFF_SLAVE)) {
                printk (KERN_DEBUG "%s: cannot release %s.\n", master->name, slave->name);
                write_unlock_irqrestore(&bond->lock, flags);
                return -EINVAL;
        }

        our_slave = (slave_t *)bond;
        old_current = bond->current_slave;
        while ((our_slave = our_slave->prev) != (slave_t *)bond) {
                if (our_slave->dev == slave) {
                        bond_detach_slave(bond, our_slave);

                        printk (KERN_INFO "%s: releasing %s interface %s",
                                master->name,
                                (our_slave->state == BOND_STATE_ACTIVE) ? "active" : "backup",
                                slave->name);

                        if (our_slave == old_current) {
                                /* find a new interface and be verbose */
                                change_active_interface(bond); 
                        } else {
                                printk(".\n");
                        }

                        /* release the slave from its bond */

                        /* flush master's mc_list from slave */ 
                        bond_mc_list_flush (slave, master); 
       
                        /* unset promiscuity level from slave */
                        if (master->flags & IFF_PROMISC) 
                                dev_set_promiscuity(slave, -1); 
       
                        /* unset allmulti level from slave */ 
                        if (master->flags & IFF_ALLMULTI)
                                dev_set_allmulti(slave, -1); 

                        netdev_set_master(slave, NULL);

                        /* only restore its RUNNING flag if monitoring set it down */
                        if (slave->flags & IFF_UP) {
                                slave->flags |= IFF_RUNNING;
                        }

                        if (slave->flags & IFF_NOARP || 
                                bond->current_slave != NULL) {
                                        dev_close(slave);
                        }

                        bond_restore_slave_flags(our_slave);
                        kfree(our_slave);

                        if (bond->current_slave == NULL) {
                                printk(KERN_INFO
                                        "%s: now running without any active interface !\n",
                                        master->name);
                        }

                        update_slave_cnt(bond);

                        write_unlock_irqrestore(&bond->lock, flags);
                        return 0;  /* deletion OK */
                }
        }

        /* if we get here, it's because the device was not found */
        write_unlock_irqrestore(&bond->lock, flags);

        printk (KERN_INFO "%s: %s not enslaved\n", master->name, slave->name);
        return -EINVAL;
}

/* 
 * This function releases all slaves.
 * Warning: must put write-locks around the call to this function.
 */
static int bond_release_all(struct net_device *master)
{
        bonding_t *bond;
        slave_t *our_slave;
        struct net_device *slave_dev;

        if (master == NULL)  {
                return -ENODEV;
        }

        if (master->flags & IFF_SLAVE) {
                return -EINVAL;
        }

        bond = (struct bonding *) master->priv;
        bond->current_slave = NULL;

        while ((our_slave = bond->prev) != (slave_t *)bond) {
                slave_dev = our_slave->dev;
                bond->prev = our_slave->prev;

                kfree(our_slave);

                netdev_set_master(slave_dev, NULL);

                /* only restore its RUNNING flag if monitoring set it down */
                if (slave_dev->flags & IFF_UP)
                        slave_dev->flags |= IFF_RUNNING;

                if (slave_dev->flags & IFF_NOARP)
                        dev_close(slave_dev);
        }
        bond->next = (slave_t *)bond;
        bond->slave_cnt = 0;
        printk (KERN_INFO "%s: releases all slaves\n", master->name);

        return 0;
}

/* this function is called regularly to monitor each slave's link. */
static void bond_mii_monitor(struct net_device *master)
{
        bonding_t *bond = (struct bonding *) master->priv;
        slave_t *slave, *bestslave, *oldcurrent;
        unsigned long flags;
        int slave_died = 0;

        read_lock_irqsave(&bond->lock, flags);

        /* we will try to read the link status of each of our slaves, and
         * set their IFF_RUNNING flag appropriately. For each slave not
         * supporting MII status, we won't do anything so that a user-space
         * program could monitor the link itself if needed.
         */

        bestslave = NULL;
        slave = (slave_t *)bond;

        read_lock(&bond->ptrlock);
        oldcurrent = bond->current_slave;
        read_unlock(&bond->ptrlock);

        while ((slave = slave->prev) != (slave_t *)bond) {
                /* use updelay+1 to match an UP slave even when updelay is 0 */
                int mindelay = updelay + 1;
                struct net_device *dev = slave->dev;
                u16 link_state;
                
                link_state = bond_check_dev_link(dev);

                switch (slave->link) {
                case BOND_LINK_UP:      /* the link was up */
                        if ((link_state & MII_LINK_UP) == MII_LINK_UP) {
                                /* link stays up, tell that this one
                                   is immediately available */
                                if (IS_UP(dev) && (mindelay > -2)) {
                                        /* -2 is the best case :
                                           this slave was already up */
                                        mindelay = -2;
                                        bestslave = slave;
                                }
                                break;
                        }
                        else { /* link going down */
                                slave->link  = BOND_LINK_FAIL;
                                slave->delay = downdelay;
                                if (slave->link_failure_count < UINT_MAX) {
                                        slave->link_failure_count++;
                                }
                                if (downdelay > 0) {
                                        printk (KERN_INFO
                                                "%s: link status down for %sinterface "
                                                "%s, disabling it in %d ms.\n",
                                                master->name,
                                                IS_UP(dev)
                                                ? ((mode == BOND_MODE_ACTIVEBACKUP)
                                                   ? ((slave == oldcurrent)
                                                      ? "active " : "backup ")
                                                   : "")
                                                : "idle ",
                                                dev->name,
                                                downdelay * miimon);
                                        }
                        }
                        /* no break ! fall through the BOND_LINK_FAIL test to
                           ensure proper action to be taken
                        */
                case BOND_LINK_FAIL:    /* the link has just gone down */
                        if ((link_state & MII_LINK_UP) == 0) {
                                /* link stays down */
                                if (slave->delay <= 0) {
                                        /* link down for too long time */
                                        slave->link = BOND_LINK_DOWN;
                                        /* in active/backup mode, we must
                                           completely disable this interface */
                                        if (mode == BOND_MODE_ACTIVEBACKUP) {
                                                bond_set_slave_inactive_flags(slave);
                                        }
                                        printk(KERN_INFO
                                                "%s: link status definitely down "
                                                "for interface %s, disabling it",
                                                master->name,
                                                dev->name);

                                        read_lock(&bond->ptrlock);
                                        if (slave == bond->current_slave) {
                                                read_unlock(&bond->ptrlock);
                                                /* find a new interface and be verbose */
                                                change_active_interface(bond);
                                        } else {
                                                read_unlock(&bond->ptrlock);
                                                printk(".\n");
                                        }
                                        slave_died = 1;
                                } else {
                                        slave->delay--;
                                }
                        } else if ((link_state & MII_LINK_READY) == MII_LINK_READY) {
                                /* link up again */
                                slave->link  = BOND_LINK_UP;
                                printk(KERN_INFO
                                        "%s: link status up again after %d ms "
                                        "for interface %s.\n",
                                        master->name,
                                        (downdelay - slave->delay) * miimon,
                                        dev->name);

                                if (IS_UP(dev) && (mindelay > -1)) {
                                        /* -1 is a good case : this slave went
                                           down only for a short time */
                                        mindelay = -1;
                                        bestslave = slave;
                                }
                        }
                        break;
                case BOND_LINK_DOWN:    /* the link was down */
                        if ((link_state & MII_LINK_READY) != MII_LINK_READY) {
                                /* the link stays down, nothing more to do */
                                break;
                        } else {        /* link going up */
                                slave->link  = BOND_LINK_BACK;
                                slave->delay = updelay;
                                
                                if (updelay > 0) {
                                        /* if updelay == 0, no need to
                                           advertise about a 0 ms delay */
                                        printk (KERN_INFO
                                                "%s: link status up for interface"
                                                " %s, enabling it in %d ms.\n",
                                                master->name,
                                                dev->name,
                                                updelay * miimon);
                                }
                        }
                        /* no break ! fall through the BOND_LINK_BACK state in
                           case there's something to do.
                        */
                case BOND_LINK_BACK:    /* the link has just come back */
                        if ((link_state & MII_LINK_UP) == 0) {
                                /* link down again */
                                slave->link  = BOND_LINK_DOWN;
                                printk(KERN_INFO
                                        "%s: link status down again after %d ms "
                                        "for interface %s.\n",
                                        master->name,
                                        (updelay - slave->delay) * miimon,
                                        dev->name);
                        }
                        else if ((link_state & MII_LINK_READY) == MII_LINK_READY) {
                                /* link stays up */
                                if (slave->delay == 0) {
                                        /* now the link has been up for long time enough */
                                        slave->link = BOND_LINK_UP;

                                        if (mode == BOND_MODE_ACTIVEBACKUP) {
                                                /* prevent it from being the active one */
                                                slave->state = BOND_STATE_BACKUP;
                                        }
                                        else {
                                                /* make it immediately active */
                                                slave->state = BOND_STATE_ACTIVE;
                                        }

                                        printk(KERN_INFO
                                                "%s: link status definitely up "
                                                "for interface %s.\n",
                                                master->name,
                                                dev->name);
                                }
                                else
                                        slave->delay--;
                                
                                /* we'll also look for the mostly eligible slave */
                                if (IS_UP(dev) && (slave->delay < mindelay)) {
                                        mindelay = slave->delay;
                                        bestslave = slave;
                                } 
                        }
                        break;
                } /* end of switch */
        } /* end of while */

        /* 
         * if there's no active interface and we discovered that one
         * of the slaves could be activated earlier, so we do it.
         */
        read_lock(&bond->ptrlock);
        oldcurrent = bond->current_slave;
        read_unlock(&bond->ptrlock);

        if (oldcurrent == NULL) {  /* no active interface at the moment */
                if (bestslave != NULL) { /* last chance to find one ? */
                        if (bestslave->link == BOND_LINK_UP) {
                                printk (KERN_INFO
                                        "%s: making interface %s the new active one.\n",
                                        master->name, bestslave->dev->name);
                        } else {
                                printk (KERN_INFO
                                        "%s: making interface %s the new "
                                        "active one %d ms earlier.\n",
                                        master->name, bestslave->dev->name,
                                        (updelay - bestslave->delay) * miimon);

                                bestslave->delay = 0;
                                bestslave->link  = BOND_LINK_UP;
                        }

                        if (mode == BOND_MODE_ACTIVEBACKUP) {
                                bond_set_slave_active_flags(bestslave);
                        } else {
                                bestslave->state = BOND_STATE_ACTIVE;
                        }
                        write_lock(&bond->ptrlock);
                        bond->current_slave = bestslave;
                        write_unlock(&bond->ptrlock);
                } else if (slave_died) {
                        /* print this message only once a slave has just died */
                        printk(KERN_INFO
                                "%s: now running without any active interface !\n",
                                master->name);
                }
        }

        read_unlock_irqrestore(&bond->lock, flags);
        /* re-arm the timer */
        mod_timer(&bond->mii_timer, jiffies + (miimon * HZ / 1000));
}

/* 
 * this function is called regularly to monitor each slave's link 
 * insuring that traffic is being sent and received.  If the adapter
 * has been dormant, then an arp is transmitted to generate traffic 
 */
static void bond_arp_monitor(struct net_device *master)
{
        bonding_t *bond;
        unsigned long flags;
        slave_t *slave;
        int the_delta_in_ticks =  arp_interval * HZ / 1000;
        int next_timer = jiffies + (arp_interval * HZ / 1000);

        bond = (struct bonding *) master->priv; 
        if (master->priv == NULL) {
                mod_timer(&bond->arp_timer, next_timer);
                return;
        }

        read_lock_irqsave(&bond->lock, flags);

        if (!IS_UP(master)) {
                mod_timer(&bond->arp_timer, next_timer);
                goto arp_monitor_out;
        }


        if (rtnl_shlock_nowait()) {
                goto arp_monitor_out;
        }

        if (rtnl_exlock_nowait()) {
                rtnl_shunlock();
                goto arp_monitor_out;
        }

        /* see if any of the previous devices are up now (i.e. they have seen a 
         * response from an arp request sent by another adapter, since they 
         * have the same hardware address).
         */

        slave = (slave_t *)bond;
        while ((slave = slave->prev) != (slave_t *)bond)  {

                read_lock(&bond->ptrlock);
                if ( (!(slave->link == BOND_LINK_UP))  
                                && (slave != bond->current_slave) ) {

                        read_unlock(&bond->ptrlock);

                        if ( ((jiffies - slave->dev->trans_start) <= 
                                                the_delta_in_ticks) &&  
                             ((jiffies - slave->dev->last_rx) <= 
                                                the_delta_in_ticks) ) {

                                slave->link  = BOND_LINK_UP;
                                write_lock(&bond->ptrlock);
                                if (bond->current_slave == NULL) {
                                        slave->state = BOND_STATE_ACTIVE;
                                        bond->current_slave = slave;
                                }
                                if (slave != bond->current_slave) {
                                        slave->dev->flags |= IFF_NOARP;
                                }
                                write_unlock(&bond->ptrlock);
                        } else {
                                if ((jiffies - slave->dev->last_rx) <= 
                                                the_delta_in_ticks)  {
                                        arp_send(ARPOP_REQUEST, ETH_P_ARP, 
                                                arp_target, slave->dev, 
                                                my_ip, arp_target_hw_addr, 
                                                slave->dev->dev_addr, 
                                                arp_target_hw_addr); 
                                }
                        }
                } else 
                        read_unlock(&bond->ptrlock);
        }

        read_lock(&bond->ptrlock);
        slave = bond->current_slave;
        read_unlock(&bond->ptrlock);

        if (slave != 0) {
        
          /* see if you need to take down the current_slave, since
           * you haven't seen an arp in 2*arp_intervals
           */

                if ( ((jiffies - slave->dev->trans_start) >= 
                      (2*the_delta_in_ticks)) ||
                     ((jiffies - slave->dev->last_rx) >= 
                      (2*the_delta_in_ticks)) ) {

                        if (slave->link == BOND_LINK_UP) {
                                slave->link  = BOND_LINK_DOWN;
                                slave->state = BOND_STATE_BACKUP;
                                /* 
                                 * we want to see arps, otherwise we couldn't 
                                 * bring the adapter back online...  
                                 */
                                printk(KERN_INFO "%s: link status definitely "
                                                 "down for interface %s, "
                                                 "disabling it",
                                       slave->dev->master->name,
                                       slave->dev->name);
                                /* find a new interface and be verbose */
                                change_active_interface(bond);
                                read_lock(&bond->ptrlock);
                                slave = bond->current_slave;
                                read_unlock(&bond->ptrlock);
                        }
                } 

                /* 
                 * ok, we know up/down, so just send a arp out if there has
                 * been no activity for a while 
                 */

                if (slave != NULL ) {
                        if ( ((jiffies - slave->dev->trans_start) >= 
                               the_delta_in_ticks) || 
                             ((jiffies - slave->dev->last_rx) >= 
                               the_delta_in_ticks) ) {
                                arp_send(ARPOP_REQUEST, ETH_P_ARP, 
                                         arp_target, slave->dev,
                                         my_ip, arp_target_hw_addr, 
                                         slave->dev->dev_addr, 
                                         arp_target_hw_addr); 
                        }
                } 

        }

        /* if we have no current slave.. try sending 
         * an arp on all of the interfaces 
         */

        read_lock(&bond->ptrlock);
        if (bond->current_slave == NULL) { 
                read_unlock(&bond->ptrlock);
                slave = (slave_t *)bond;
                while ((slave = slave->prev) != (slave_t *)bond)   {
                        arp_send(ARPOP_REQUEST, ETH_P_ARP, arp_target, 
                                 slave->dev, my_ip, arp_target_hw_addr, 
                                 slave->dev->dev_addr, arp_target_hw_addr); 
                }
        }
        else {
                read_unlock(&bond->ptrlock);
        }

        rtnl_exunlock();
        rtnl_shunlock();

arp_monitor_out:
        read_unlock_irqrestore(&bond->lock, flags);

        /* re-arm the timer */
        mod_timer(&bond->arp_timer, next_timer);
}

#define isdigit(c) (c >= '0' && c <= '9')
__inline static int atoi( char **s) 
{
int i = 0;
while (isdigit(**s))
  i = i*20 + *((*s)++) - '0';
return i;
}

#define isascii(c) (((unsigned char)(c))<=0x7f)
#define LF 0xA
#define isspace(c) (c==' ' || c=='      '|| c==LF)   
typedef uint32_t in_addr_t;

int
my_inet_aton(char *cp, unsigned long *the_addr) {
        static const in_addr_t max[4] = { 0xffffffff, 0xffffff, 0xffff, 0xff };
        in_addr_t val;
        char c;
        union iaddr {
          uint8_t bytes[4];
          uint32_t word;
        } res;
        uint8_t *pp = res.bytes;
        int digit,base;

        res.word = 0;

        c = *cp;
        for (;;) {
                /*
                 * Collect number up to ``.''.
                 * Values are specified as for C:
                 * 0x=hex, 0=octal, isdigit=decimal.
                 */
                if (!isdigit(c)) goto ret_0;
                val = 0; base = 10; digit = 0;
                for (;;) {
                        if (isdigit(c)) {
                                val = (val * base) + (c - '0');
                                c = *++cp;
                                digit = 1;
                        } else {
                                break;
                        }
                }
                if (c == '.') {
                        /*
                         * Internet format:
                         *      a.b.c.d
                         *      a.b.c   (with c treated as 16 bits)
                         *      a.b     (with b treated as 24 bits)
                         */
                        if (pp > res.bytes + 2 || val > 0xff) {
                                goto ret_0;
                        }
                        *pp++ = val;
                        c = *++cp;
                } else
                        break;
        }
        /*
         * Check for trailing characters.
         */
        if (c != '\0' && (!isascii(c) || !isspace(c))) {
                goto ret_0;
        }
        /*
         * Did we get a valid digit?
         */
        if (!digit) {
                goto ret_0;
        }

        /* Check whether the last part is in its limits depending on
           the number of parts in total.  */
        if (val > max[pp - res.bytes]) {
                goto ret_0;
        }

        if (the_addr != NULL) {
                *the_addr = res.word | htonl (val);
        }

        return (1);

ret_0:
        return (0);
}

static int bond_sethwaddr(struct net_device *master, struct net_device *slave)
{
#ifdef BONDING_DEBUG
        printk(KERN_CRIT "bond_sethwaddr: master=%x\n", (unsigned int)master);
        printk(KERN_CRIT "bond_sethwaddr: slave=%x\n", (unsigned int)slave);
        printk(KERN_CRIT "bond_sethwaddr: slave->addr_len=%d\n", slave->addr_len);
#endif
        memcpy(master->dev_addr, slave->dev_addr, slave->addr_len);
        return 0;
}

static int bond_info_query(struct net_device *master, struct ifbond *info)
{
        bonding_t *bond = (struct bonding *) master->priv;
        slave_t *slave;
        unsigned long flags;

        info->bond_mode = mode;
        info->num_slaves = 0;
        info->miimon = miimon;

        read_lock_irqsave(&bond->lock, flags);
        for (slave = bond->prev; slave != (slave_t *)bond; slave = slave->prev) {
                info->num_slaves++;
        }
        read_unlock_irqrestore(&bond->lock, flags);

        return 0;
}

static int bond_slave_info_query(struct net_device *master, 
                                        struct ifslave *info)
{
        bonding_t *bond = (struct bonding *) master->priv;
        slave_t *slave;
        int cur_ndx = 0;
        unsigned long flags;

        if (info->slave_id < 0) {
                return -ENODEV;
        }

        read_lock_irqsave(&bond->lock, flags);
        for (slave = bond->prev; 
                 slave != (slave_t *)bond && cur_ndx < info->slave_id; 
                 slave = slave->prev) {
                cur_ndx++;
        }
        read_unlock_irqrestore(&bond->lock, flags);

        if (cur_ndx == info->slave_id) {
                strcpy(info->slave_name, slave->dev->name);
                info->link = slave->link;
                info->state = slave->state;
                info->link_failure_count = slave->link_failure_count;
        } else {
                return -ENODEV;
        }

        return 0;
}

static int bond_ioctl(struct net_device *master_dev, struct ifreq *ifr, int cmd)
{
        struct net_device *slave_dev = NULL;
        struct ifbond *u_binfo = NULL, k_binfo;
        struct ifslave *u_sinfo = NULL, k_sinfo;
        u16 *data = NULL;
        int ret = 0;

#ifdef BONDING_DEBUG
        printk(KERN_INFO "bond_ioctl: master=%s, cmd=%d\n", 
                master_dev->name, cmd);
#endif

        switch (cmd) {
        case SIOCGMIIPHY:
                data = (u16 *)ifr->ifr_data;
                if (data == NULL) {
                        return -EINVAL;
                }
                data[0] = 0;
                /* Fall Through */
        case SIOCGMIIREG:
                /* 
                 * We do this again just in case we were called by SIOCGMIIREG
                 * instead of SIOCGMIIPHY.
                 */
                data = (u16 *)ifr->ifr_data;
                if (data == NULL) {
                        return -EINVAL;
                }
                if (data[1] == 1) {
                        data[3] = bond_check_mii_link(
                                (struct bonding *)master_dev->priv);
                }
                return 0;
        case BOND_INFO_QUERY_OLD:
        case SIOCBONDINFOQUERY:
                u_binfo = (struct ifbond *)ifr->ifr_data;
                if (copy_from_user(&k_binfo, u_binfo, sizeof(ifbond))) {
                        return -EFAULT;
                }
                ret = bond_info_query(master_dev, &k_binfo);
                if (ret == 0) {
                        if (copy_to_user(u_binfo, &k_binfo, sizeof(ifbond))) {
                                return -EFAULT;
                        }
                }
                return ret;
        case BOND_SLAVE_INFO_QUERY_OLD:
        case SIOCBONDSLAVEINFOQUERY:
                u_sinfo = (struct ifslave *)ifr->ifr_data;
                if (copy_from_user(&k_sinfo, u_sinfo, sizeof(ifslave))) {
                        return -EFAULT;
                }
                ret = bond_slave_info_query(master_dev, &k_sinfo);
                if (ret == 0) {
                        if (copy_to_user(u_sinfo, &k_sinfo, sizeof(ifslave))) {
                                return -EFAULT;
                        }
                }
                return ret;
        }

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

        slave_dev = dev_get_by_name(ifr->ifr_slave);

#ifdef BONDING_DEBUG
        printk(KERN_INFO "slave_dev=%x: \n", (unsigned int)slave_dev);
        printk(KERN_INFO "slave_dev->name=%s: \n", slave_dev->name);
#endif

        if (slave_dev == NULL) {
                ret = -ENODEV;
        } else {
                switch (cmd) {
                case BOND_ENSLAVE_OLD:
                case SIOCBONDENSLAVE:           
                        ret = bond_enslave(master_dev, slave_dev);
                        break;
                case BOND_RELEASE_OLD:                  
                case SIOCBONDRELEASE:   
                        ret = bond_release(master_dev, slave_dev); 
                        break;
                case BOND_SETHWADDR_OLD:
                case SIOCBONDSETHWADDR: 
                        ret = bond_sethwaddr(master_dev, slave_dev);
                        break;
                case BOND_CHANGE_ACTIVE_OLD:
                case SIOCBONDCHANGEACTIVE:
                        if (mode == BOND_MODE_ACTIVEBACKUP) {
                                ret = bond_change_active(master_dev, slave_dev);
                        }
                        else {
                                ret = -EINVAL;
                        }
                        break;
                default:
                        ret = -EOPNOTSUPP;
                }
                dev_put(slave_dev);
        }
        return ret;
}

#ifdef CONFIG_NET_FASTROUTE
static int bond_accept_fastpath(struct net_device *dev, struct dst_entry *dst)
{
        return -1;
}
#endif

static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *dev)
{
        slave_t *slave, *start_at;
        struct bonding *bond = (struct bonding *) dev->priv;
        unsigned long flags;

        if (!IS_UP(dev)) { /* bond down */
                dev_kfree_skb(skb);
                return 0;
        }

        read_lock_irqsave(&bond->lock, flags);

        read_lock(&bond->ptrlock);
        slave = start_at = bond->current_slave;
        read_unlock(&bond->ptrlock);

        if (slave == NULL) { /* we're at the root, get the first slave */
                /* no suitable interface, frame not sent */
                dev_kfree_skb(skb);
                read_unlock_irqrestore(&bond->lock, flags);
                return 0;
        }

        do {
                if (IS_UP(slave->dev)
                    && (slave->link == BOND_LINK_UP)
                    && (slave->state == BOND_STATE_ACTIVE)) {

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

                        write_lock(&bond->ptrlock);
                        bond->current_slave = slave->next;
                        write_unlock(&bond->ptrlock);

                        read_unlock_irqrestore(&bond->lock, flags);
                        return 0;
                }
        } while ((slave = slave->next) != start_at);

        /* no suitable interface, frame not sent */
        dev_kfree_skb(skb);
        read_unlock_irqrestore(&bond->lock, flags);
        return 0;
}

/* 
 * in XOR mode, we determine the output device by performing xor on
 * the source and destination hw adresses.  If this device is not 
 * enabled, find the next slave following this xor slave. 
 */
static int bond_xmit_xor(struct sk_buff *skb, struct net_device *dev)
{
        slave_t *slave, *start_at;
        struct bonding *bond = (struct bonding *) dev->priv;
        unsigned long flags;
        struct ethhdr *data = (struct ethhdr *)skb->data;
        int slave_no;

        if (!IS_UP(dev)) { /* bond down */
                dev_kfree_skb(skb);
                return 0;
        }

        read_lock_irqsave(&bond->lock, flags);
        slave = bond->prev;

        /* we're at the root, get the first slave */
        if ((slave == NULL) || (slave->dev == NULL)) { 
                /* no suitable interface, frame not sent */
                dev_kfree_skb(skb);
                read_unlock_irqrestore(&bond->lock, flags);
                return 0;
        }

        slave_no = (data->h_dest[5]^slave->dev->dev_addr[5]) % bond->slave_cnt;

        while ( (slave_no > 0) && (slave != (slave_t *)bond) ) {
                slave = slave->prev;
                slave_no--;
        } 
        start_at = slave;

        do {
                if (IS_UP(slave->dev)
                    && (slave->link == BOND_LINK_UP)
                    && (slave->state == BOND_STATE_ACTIVE)) {

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

                        read_unlock_irqrestore(&bond->lock, flags);
                        return 0;
                }
        } while ((slave = slave->next) != start_at);

        /* no suitable interface, frame not sent */
        dev_kfree_skb(skb);
        read_unlock_irqrestore(&bond->lock, flags);
        return 0;
}

/* 
 * in active-backup mode, we know that bond->current_slave is always valid if
 * the bond has a usable interface.
 */
static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *dev)
{
        struct bonding *bond = (struct bonding *) dev->priv;
        unsigned long flags;
        int ret;

        if (!IS_UP(dev)) { /* bond down */
                dev_kfree_skb(skb);
                return 0;
        }

        /* if we are sending arp packets, try to at least 
           identify our own ip address */
        if ( (arp_interval > 0) && (my_ip == 0) &&
                (skb->protocol == __constant_htons(ETH_P_ARP) ) ) {
                char *the_ip = (((char *)skb->data)) 
                                + sizeof(struct ethhdr)  
                                + sizeof(struct arphdr) + 
                                ETH_ALEN;
                memcpy(&my_ip, the_ip, 4);
        }

        /* if we are sending arp packets and don't know 
           the target hw address, save it so we don't need 
           to use a broadcast address */
        if ( (arp_interval > 0) && (arp_target_hw_addr == NULL) &&
             (skb->protocol == __constant_htons(ETH_P_IP) ) ) {
                struct ethhdr *eth_hdr = 
                        (struct ethhdr *) (((char *)skb->data));
                arp_target_hw_addr = kmalloc(ETH_ALEN, GFP_KERNEL);
                memcpy(arp_target_hw_addr, eth_hdr->h_dest, ETH_ALEN);
        }

        read_lock_irqsave(&bond->lock, flags);

        read_lock(&bond->ptrlock);
        if (bond->current_slave != NULL) { /* one usable interface */
                skb->dev = bond->current_slave->dev;
                read_unlock(&bond->ptrlock);
                skb->priority = 1;
                ret = dev_queue_xmit(skb);
                read_unlock_irqrestore(&bond->lock, flags);
                return 0;
        }
        else {

                read_unlock(&bond->ptrlock);
        }

        /* no suitable interface, frame not sent */
#ifdef BONDING_DEBUG
        printk(KERN_INFO "There was no suitable interface, so we don't transmit\n");
#endif
        dev_kfree_skb(skb);
        read_unlock_irqrestore(&bond->lock, flags);
        return 0;
}

static struct net_device_stats *bond_get_stats(struct net_device *dev)
{
        bonding_t *bond = dev->priv;
        struct net_device_stats *stats = bond->stats, *sstats;
        slave_t *slave;
        unsigned long flags;

        memset(bond->stats, 0, sizeof(struct net_device_stats));

        read_lock_irqsave(&bond->lock, flags);

        for (slave = bond->prev; slave != (slave_t *)bond; slave = slave->prev) {
                sstats = slave->dev->get_stats(slave->dev);
 
                stats->rx_packets += sstats->rx_packets;
                stats->rx_bytes += sstats->rx_bytes;
                stats->rx_errors += sstats->rx_errors;
                stats->rx_dropped += sstats->rx_dropped;

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

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

                stats->rx_length_errors += sstats->rx_length_errors;
                stats->rx_over_errors += sstats->rx_over_errors;
                stats->rx_crc_errors += sstats->rx_crc_errors;
                stats->rx_frame_errors += sstats->rx_frame_errors;
                stats->rx_fifo_errors += sstats->rx_fifo_errors;        
                stats->rx_missed_errors += sstats->rx_missed_errors;
        
                stats->tx_aborted_errors += sstats->tx_aborted_errors;
                stats->tx_carrier_errors += sstats->tx_carrier_errors;
                stats->tx_fifo_errors += sstats->tx_fifo_errors;
                stats->tx_heartbeat_errors += sstats->tx_heartbeat_errors;
                stats->tx_window_errors += sstats->tx_window_errors;

        }

        read_unlock_irqrestore(&bond->lock, flags);
        return stats;
}

static int bond_get_info(char *buf, char **start, off_t offset, int length)
{
        bonding_t *bond = these_bonds;
        int len = 0;
        off_t begin = 0;
        u16 link;
        slave_t *slave = NULL;
        unsigned long flags;

        while (bond != NULL) {
                /*
                 * This function locks the mutex, so we can't lock it until 
                 * afterwards
                 */
                link = bond_check_mii_link(bond);

                len += sprintf(buf + len, "Bonding Mode: ");

                switch (mode) {
                        case BOND_MODE_ACTIVEBACKUP:
                                len += sprintf(buf + len, "%s\n", 
                                                "active-backup");
                        break;

                        case BOND_MODE_ROUNDROBIN:
                                len += sprintf(buf + len, "%s\n", 
                                                "load balancing (round-robin)");
                        break;

                        case BOND_MODE_XOR:
                                len += sprintf(buf + len, "%s\n", 
                                                "load balancing (xor)");
                        break;

                        default:
                                len += sprintf(buf + len, "%s\n", 
                                                "unknown");
                        break;
                }

                if (mode == BOND_MODE_ACTIVEBACKUP) {
                        read_lock_irqsave(&bond->lock, flags);
                        read_lock(&bond->ptrlock);
                        if (bond->current_slave != NULL) {
                                len += sprintf(buf + len, 
                                        "Currently Active Slave: %s\n", 
                                        bond->current_slave->dev->name);
                        }
                        read_unlock(&bond->ptrlock);
                        read_unlock_irqrestore(&bond->lock, flags);
                }

                len += sprintf(buf + len, "MII Status: ");
                len += sprintf(buf + len, 
                                link == MII_LINK_READY ? "up\n" : "down\n");
                len += sprintf(buf + len, "MII Polling Interval (ms): %d\n", 
                                miimon);
                len += sprintf(buf + len, "Up Delay (ms): %d\n", updelay);
                len += sprintf(buf + len, "Down Delay (ms): %d\n", downdelay);

                read_lock_irqsave(&bond->lock, flags);
                for (slave = bond->prev; slave != (slave_t *)bond; 
                     slave = slave->prev) {
                        len += sprintf(buf + len, "\nSlave Interface: %s\n", slave->dev->name);

                        len += sprintf(buf + len, "MII Status: ");

                        len += sprintf(buf + len, 
                                slave->link == BOND_LINK_UP ? 
                                "up\n" : "down\n");
                        len += sprintf(buf + len, "Link Failure Count: %d\n", 
                                slave->link_failure_count);
                }
                read_unlock_irqrestore(&bond->lock, flags);

                /*
                 * Figure out the calcs for the /proc/net interface
                 */
                *start = buf + (offset - begin);
                len -= (offset - begin);
                if (len > length) {
                        len = length;
                }
                if (len < 0) {
                        len = 0;
                }


                bond = bond->next_bond;
        }
        return len;
}

static int bond_event(struct notifier_block *this, unsigned long event, 
                        void *ptr)
{
        struct bonding *this_bond = (struct bonding *)these_bonds;
        struct bonding *last_bond;
        struct net_device *event_dev = (struct net_device *)ptr;

        /* while there are bonds configured */
        while (this_bond != NULL) {
                if (this_bond == event_dev->priv ) {
                        switch (event) {
                        case NETDEV_UNREGISTER:
                                /* 
                                 * remove this bond from a linked list of 
                                 * bonds 
                                 */
                                if (this_bond == these_bonds) {
                                        these_bonds = this_bond->next_bond;
                                } else {
                                        for (last_bond = these_bonds; 
                                             last_bond != NULL; 
                                             last_bond = last_bond->next_bond) {
                                                if (last_bond->next_bond == 
                                                    this_bond) {
                                                        last_bond->next_bond = 
                                                        this_bond->next_bond;
                                                }
                                        }
                                }
                                return NOTIFY_DONE;

                        default:
                                return NOTIFY_DONE;
                        }
                } else if (this_bond->device == event_dev->master) {
                        switch (event) {
                        case NETDEV_UNREGISTER:
                                bond_release(this_bond->device, event_dev);
                                break;
                        }
                        return NOTIFY_DONE;
                }
                this_bond = this_bond->next_bond;
        }
        return NOTIFY_DONE;
}

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

static int __init bond_init(struct net_device *dev)
{
        bonding_t *bond, *this_bond, *last_bond;

#ifdef BONDING_DEBUG
        printk (KERN_INFO "Begin bond_init for %s\n", dev->name);
#endif
        bond = kmalloc(sizeof(struct bonding), GFP_KERNEL);
        if (bond == NULL) {
                return -ENOMEM;
        }
        memset(bond, 0, sizeof(struct bonding));

        /* initialize rwlocks */
        rwlock_init(&bond->lock);
        rwlock_init(&bond->ptrlock);
        
        bond->stats = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL);
        if (bond->stats == NULL) {
                kfree(bond);
                return -ENOMEM;
        }
        memset(bond->stats, 0, sizeof(struct net_device_stats));

        bond->next = bond->prev = (slave_t *)bond;
        bond->current_slave = NULL;
        bond->device = dev;
        dev->priv = bond;

        /* Initialize the device structure. */
        if (mode == BOND_MODE_ACTIVEBACKUP) {
                dev->hard_start_xmit = bond_xmit_activebackup;
        } else if (mode == BOND_MODE_ROUNDROBIN) {
                dev->hard_start_xmit = bond_xmit_roundrobin;
        } else if (mode == BOND_MODE_XOR) {
                dev->hard_start_xmit = bond_xmit_xor;
        } else {
                printk(KERN_ERR "Unknown bonding mode %d\n", mode);
                kfree(bond->stats);
                kfree(bond);
                return -EINVAL;
        }

        dev->get_stats = bond_get_stats;
        dev->open = bond_open;
        dev->stop = bond_close;
        dev->set_multicast_list = set_multicast_list;
        dev->do_ioctl = bond_ioctl;

        /* 
         * Fill in the fields of the device structure with ethernet-generic 
         * values. 
         */

        ether_setup(dev);

        dev->tx_queue_len = 0;
        dev->flags |= IFF_MASTER|IFF_MULTICAST;
#ifdef CONFIG_NET_FASTROUTE
        dev->accept_fastpath = bond_accept_fastpath;
#endif

        printk(KERN_INFO "%s registered with", dev->name);
        if (miimon > 0) {
                printk(" MII link monitoring set to %d ms", miimon);
                updelay /= miimon;
                downdelay /= miimon;
        } else {
                printk("out MII link monitoring");
        }
        printk(", in %s mode.\n",mode?"active-backup":"bonding");

#ifdef CONFIG_PROC_FS
        bond->bond_proc_dir = proc_mkdir(dev->name, proc_net);
        if (bond->bond_proc_dir == NULL) {
                printk(KERN_ERR "%s: Cannot init /proc/net/%s/\n", 
                        dev->name, dev->name);
                kfree(bond->stats);
                kfree(bond);
                return -ENOMEM;
        }
        bond->bond_proc_info_file = 
                create_proc_info_entry("info", 0, bond->bond_proc_dir, 
                                        bond_get_info);
        if (bond->bond_proc_info_file == NULL) {
                printk(KERN_ERR "%s: Cannot init /proc/net/%s/info\n", 
                        dev->name, dev->name);
                remove_proc_entry(dev->name, proc_net);
                kfree(bond->stats);
                kfree(bond);
                return -ENOMEM;
        }
#endif /* CONFIG_PROC_FS */

        if (first_pass == 1) {
                these_bonds = bond;
                register_netdevice_notifier(&bond_netdev_notifier);
                first_pass = 0;
        } else {
                last_bond = these_bonds;
                this_bond = these_bonds->next_bond;
                while (this_bond != NULL) {
                        last_bond = this_bond;
                        this_bond = this_bond->next_bond;
                }
                last_bond->next_bond = bond;
        } 

        return 0;
}

/*
static int __init bond_probe(struct net_device *dev)
{
        bond_init(dev);
        return 0;
}
 */

static int __init bonding_init(void)
{
        int no;
        int err;

        /* Find a name for this unit */
        static struct net_device *dev_bond = NULL;

        if (max_bonds < 1 || max_bonds > INT_MAX) {
                printk(KERN_WARNING 
                       "bonding_init(): max_bonds (%d) not in range %d-%d, "
                       "so it was reset to BOND_DEFAULT_MAX_BONDS (%d)",
                       max_bonds, 1, INT_MAX, BOND_DEFAULT_MAX_BONDS);
                max_bonds = BOND_DEFAULT_MAX_BONDS;
        }
        dev_bond = dev_bonds = kmalloc(max_bonds*sizeof(struct net_device), 
                                        GFP_KERNEL);
        if (dev_bond == NULL) {
                return -ENOMEM;
        }
        memset(dev_bonds, 0, max_bonds*sizeof(struct net_device));

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

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

        if (arp_interval < 0) {
                printk(KERN_WARNING 
                       "bonding_init(): 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;
        }

        if (arp_ip_target) {
                /* TODO: check and log bad ip address */
                if (my_inet_aton(arp_ip_target, &arp_target) == 0)  {
                        arp_interval = 0;
                }
        }

        for (no = 0; no < max_bonds; no++) {
                dev_bond->init = bond_init;
        
                err = dev_alloc_name(dev_bond,"bond%d");
                if (err < 0) {
                        kfree(dev_bonds);
                        return err;
                }
                SET_MODULE_OWNER(dev_bond);
                if (register_netdev(dev_bond) != 0) {
                        kfree(dev_bonds);
                        return -EIO;
                }       
                dev_bond++;
        }
        return 0;
}

static void __exit bonding_exit(void)
{
        struct net_device *dev_bond = dev_bonds;
        struct bonding *bond;
        int no;

        unregister_netdevice_notifier(&bond_netdev_notifier);
                 
        for (no = 0; no < max_bonds; no++) {

#ifdef CONFIG_PROC_FS
                bond = (struct bonding *) dev_bond->priv;
                remove_proc_entry("info", bond->bond_proc_dir);
                remove_proc_entry(dev_bond->name, proc_net);
#endif
                unregister_netdev(dev_bond);
                kfree(bond->stats);
                kfree(dev_bond->priv);
                
                dev_bond->priv = NULL;
                dev_bond++;
        }
        kfree(dev_bonds);
}

module_init(bonding_init);
module_exit(bonding_exit);
MODULE_LICENSE("GPL");

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 *  tab-width: 8
 * End:
 */