FreeBSD/Linux Kernel Cross Reference
sys/drivers/net/bonding/bond_main.c

     /*
      * originally based on the dummy device.
      *
      * Copyright 1999, Thomas Davis, tadavis@lbl.gov.  
      * Licensed under the GPL. Based on dummy.c, and eql.c devices.
      *
      * bonding.c: an Ethernet Bonding driver
      *
      * This is useful to talk to a Cisco EtherChannel compatible equipment:
     *      Cisco 5500
     *      Sun Trunking (Solaris)
     *      Alteon AceDirector Trunks
     *      Linux Bonding
     *      and probably many L2 switches ...
     *
     * How it works:
     *    ifconfig bond0 ipaddress netmask up
     *      will setup a network device, with an ip address.  No mac address 
     *      will be assigned at this time.  The hw mac address will come from 
     *      the first slave bonded to the channel.  All slaves will then use 
     *      this hw mac address.
     *
     *    ifconfig bond0 down
     *         will release all slaves, marking them as down.
     *
     *    ifenslave bond0 eth0
     *      will attach eth0 to bond0 as a slave.  eth0 hw mac address will either
     *      a: be used as initial mac address
     *      b: if a hw mac address already is there, eth0's hw mac address 
     *         will then be set from bond0.
     *
     * 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.
    *
    * 2002/06/10 - Tony Cureington <tony.cureington * hp_com>
    *     - corrected uninitialized pointer (ifr.ifr_data) in bond_check_dev_link;
    *       actually changed function to use MIIPHY, then MIIREG, and finally
    *       ETHTOOL 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)
    *
    * 2002/08/30 - Jay Vosburgh <fubar at us dot ibm dot com>
    *     - Removed acquisition of xmit_lock in set_multicast_list; caused
    *       deadlock on SMP (lock is held by caller).
    *     - Revamped SIOCGMIIPHY, SIOCGMIIREG portion of bond_check_dev_link().
    *
    * 2002/09/18 - Jay Vosburgh <fubar at us dot ibm dot com>
    *     - Fixed up bond_check_dev_link() (and callers): removed some magic
    *       numbers, banished local MII_ defines, wrapped ioctl calls to
    *       prevent EFAULT errors
    *
    * 2002/9/30 - Jay Vosburgh <fubar at us dot ibm dot com>
    *     - make sure the ip target matches the arp_target before saving the
    *       hw address.
    *
    * 2002/9/30 - Dan Eisner <eisner at 2robots dot com>
    *     - make sure my_ip is set before taking down the link, since
    *       not all switches respond if the source ip is not set.
    *
    * 2002/10/8 - Janice Girouard <girouard at us dot ibm dot com>
    *     - read in the local ip address when enslaving a device
    *     - add primary support
    *     - make sure 2*arp_interval has passed when a new device
    *       is brought on-line before taking it down.
    *
    * 2002/09/11 - Philippe De Muyter <phdm at macqel dot be>
    *     - Added bond_xmit_broadcast logic.
    *     - Added bond_mode() support function.
    *
    * 2002/10/26 - Laurent Deniel <laurent.deniel at free.fr>
    *     - allow to register multicast addresses only on active slave
    *       (useful in active-backup mode)
    *     - add multicast module parameter
    *     - fix deletion of multicast groups after unloading module
    *
    * 2002/11/06 - Kameshwara Rayaprolu <kameshwara.rao * wipro_com>
    *     - Changes to prevent panic from closing the device twice; if we close 
    *       the device in bond_release, we must set the original_flags to down 
    *       so it won't be closed again by the network layer.
    *
    * 2002/11/07 - Tony Cureington <tony.cureington * hp_com>
    *     - Fix arp_target_hw_addr memory leak
    *     - Created activebackup_arp_monitor function to handle arp monitoring 
    *       in active backup mode - the bond_arp_monitor had several problems... 
    *       such as allowing slaves to tx arps sequentially without any delay 
    *       for a response
    *     - Renamed bond_arp_monitor to loadbalance_arp_monitor and re-wrote
    *       this function to just handle arp monitoring in load-balancing mode;
    *       it is a lot more compact now
    *     - Changes to ensure one and only one slave transmits in active-backup 
    *       mode
    *     - Robustesize parameters; warn users about bad combinations of 
    *       parameters; also if miimon is specified and a network driver does 
    *       not support MII or ETHTOOL, inform the user of this
    *     - Changes to support link_failure_count when in arp monitoring mode
    *     - Fix up/down delay reported in /proc
    *     - Added version; log version; make version available from "modinfo -d"
    *     - Fixed problem in bond_check_dev_link - if the first IOCTL (SIOCGMIIPH)
    *       failed, the ETHTOOL ioctl never got a chance
    *
    * 2002/11/16 - Laurent Deniel <laurent.deniel at free.fr>
    *     - fix multicast handling in activebackup_arp_monitor
    *     - remove one unnecessary and confusing current_slave == slave test 
    *       in activebackup_arp_monitor
    *
    *  2002/11/17 - Laurent Deniel <laurent.deniel at free.fr>
    *     - fix bond_slave_info_query when slave_id = num_slaves
    *
    *  2002/11/19 - Janice Girouard <girouard at us dot ibm dot com>
    *     - correct ifr_data reference.  Update ifr_data reference
    *       to mii_ioctl_data struct values to avoid confusion.
    *
    *  2002/11/22 - Bert Barbe <bert.barbe at oracle dot com>
    *      - Add support for multiple arp_ip_target
    *
    *  2002/12/13 - Jay Vosburgh <fubar at us dot ibm dot com>
    *      - Changed to allow text strings for mode and multicast, e.g.,
    *        insmod bonding mode=active-backup.  The numbers still work.
    *        One change: an invalid choice will cause module load failure,
    *        rather than the previous behavior of just picking one.
    *      - Minor cleanups; got rid of dup ctype stuff, atoi function
    * 
    * 2003/02/07 - Jay Vosburgh <fubar at us dot ibm dot com>
    *      - Added use_carrier module parameter that causes miimon to
    *        use netif_carrier_ok() test instead of MII/ETHTOOL ioctls.
    *      - Minor cleanups; consolidated ioctl calls to one function.
    *
    * 2003/02/07 - Tony Cureington <tony.cureington * hp_com>
    *      - Fix bond_mii_monitor() logic error that could result in
    *        bonding round-robin mode ignoring links after failover/recovery
    *
    * 2003/03/17 - Jay Vosburgh <fubar at us dot ibm dot com>
    *      - kmalloc fix (GPF_KERNEL to GPF_ATOMIC) reported by
    *        Shmulik dot Hen at intel.com.
    *      - Based on discussion on mailing list, changed use of
    *        update_slave_cnt(), created wrapper functions for adding/removing
    *        slaves, changed bond_xmit_xor() to check slave_cnt instead of
    *        checking slave and slave->dev (which only worked by accident).
    *      - Misc code cleanup: get arp_send() prototype from header file,
    *        add max_bonds to bonding.txt.
    *
    * 2003/03/18 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
    *              Shmulik Hen <shmulik.hen at intel dot com>
    *      - Make sure only bond_attach_slave() and bond_detach_slave() can
    *        manipulate the slave list, including slave_cnt, even when in
    *        bond_release_all().
    *      - Fixed hang in bond_release() with traffic running:
    *        netdev_set_master() must not be called from within the bond lock.
    *
    * 2003/03/18 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
    *              Shmulik Hen <shmulik.hen at intel dot com>
    *      - Fixed hang in bond_enslave() with traffic running:
    *        netdev_set_master() must not be called from within the bond lock.
    *
    * 2003/03/18 - Amir Noam <amir.noam at intel dot com>
    *      - Added support for getting slave's speed and duplex via ethtool.
    *        Needed for 802.3ad and other future modes.
    *
    * 2003/03/18 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
    *              Shmulik Hen <shmulik.hen at intel dot com>
    *      - Enable support of modes that need to use the unique mac address of
    *        each slave.
    *        * bond_enslave(): Moved setting the slave's mac address, and
    *          openning it, from the application to the driver. This breaks
    *          backward comaptibility with old versions of ifenslave that open
    *           the slave before enalsving it !!!.
    *        * bond_release(): The driver also takes care of closing the slave
    *          and restoring its original mac address.
    *      - Removed the code that restores all base driver's flags.
    *        Flags are automatically restored once all undo stages are done
    *        properly.
    *      - Block possibility of enslaving before the master is up. This
    *        prevents putting the system in an unstable state.
    *
    * 2003/03/18 - Amir Noam <amir.noam at intel dot com>,
    *              Tsippy Mendelson <tsippy.mendelson at intel dot com> and
    *              Shmulik Hen <shmulik.hen at intel dot com>
    *    - Added support for IEEE 802.3ad Dynamic link aggregation mode.
    *
    * 2003/05/01 - Amir Noam <amir.noam at intel dot com>
    *    - Added ABI version control to restore compatibility between
    *      new/old ifenslave and new/old bonding.
    *
    * 2003/05/01 - Shmulik Hen <shmulik.hen at intel dot com>
    *    - Fixed bug in bond_release_all(): save old value of current_slave
    *      before setting it to NULL.
    *    - Changed driver versioning scheme to include version number instead
    *      of release date (that is already in another field). There are 3
    *      fields X.Y.Z where:
    *            X - Major version - big behavior changes
    *            Y - Minor version - addition of features
    *            Z - Extra version - minor changes and bug fixes
    *      The current version is 1.0.0 as a base line.
    *
    * 2003/05/01 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
    *              Amir Noam <amir.noam at intel dot com>
    *      - Added support for lacp_rate module param.
    *      - Code beautification and style changes (mainly in comments).
    *        new version - 1.0.1
    *
    * 2003/05/01 - Shmulik Hen <shmulik.hen at intel dot com>
    *      - Based on discussion on mailing list, changed locking scheme
    *        to use lock/unlock or lock_bh/unlock_bh appropriately instead
    *        of lock_irqsave/unlock_irqrestore. The new scheme helps exposing
    *        hidden bugs and solves system hangs that occurred due to the fact
    *        that holding lock_irqsave doesn't prevent softirqs from running.
    *        This also increases total throughput since interrupts are not
    *        blocked on each transmitted packets or monitor timeout.
    *        new version - 2.0.0
    *
    * 2003/05/01 - Shmulik Hen <shmulik.hen at intel dot com>
    *      - Added support for Transmit load balancing mode.
    *      - Concentrate all assignments of current_slave to a single point
    *        so specific modes can take actions when the primary adapter is
    *        changed.
    *      - Take the updelay parameter into consideration during bond_enslave
    *        since some adapters loose their link during setting the device.
    *      - Renamed bond_3ad_link_status_changed() to
    *        bond_3ad_handle_link_change() for compatibility with TLB.
    *        new version - 2.1.0
    *
    * 2003/05/01 - Tsippy Mendelson <tsippy.mendelson at intel dot com>
    *      - Added support for Adaptive load balancing mode which is
    *        equivalent to Transmit load balancing + Receive load balancing.
    *        new version - 2.2.0
    *
    * 2003/05/15 - Jay Vosburgh <fubar at us dot ibm dot com>
    *      - Applied fix to activebackup_arp_monitor posted to bonding-devel
    *        by Tony Cureington <tony.cureington * hp_com>.  Fixes ARP
    *        monitor endless failover bug.  Version to 2.2.10
    *
    * 2003/05/20 - Amir Noam <amir.noam at intel dot com>
    *      - Fixed bug in ABI version control - Don't commit to a specific
    *        ABI version if receiving unsupported ioctl commands.
    *
    * 2003/05/22 - Jay Vosburgh <fubar at us dot ibm dot com>
    *      - In conjunction with fix for ifenslave -c, in
    *        bond_change_active(), changing to the already active slave
    *        is no longer an error (it successfully does nothing).
    *
    * 2003/06/30 - Amir Noam <amir.noam at intel dot com>
    *      - Fixed bond_change_active() for ALB/TLB modes.
    */
   
   #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/ptrace.h>
   #include <linux/ioport.h>
   #include <linux/in.h>
   #include <linux/ip.h>
   #include <linux/slab.h>
   #include <linux/string.h>
   #include <linux/init.h>
   #include <linux/timer.h>
   #include <linux/socket.h>
   #include <linux/ctype.h>
   #include <linux/inet.h>
   #include <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/inetdevice.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 <net/arp.h>
   #include <linux/mii.h>
   #include <linux/ethtool.h>
   #include "bonding.h"
   #include "bond_3ad.h"
   #include "bond_alb.h"
   
   #define DRV_VERSION             "2.2.14"
   #define DRV_RELDATE             "June 30, 2003"
   #define DRV_NAME                "bonding"
   #define DRV_DESCRIPTION         "Ethernet Channel Bonding Driver"
   
   static const char *version =
   DRV_NAME ".c:v" DRV_VERSION " (" DRV_RELDATE ")\n";
   
   /* monitor all links that often (in milliseconds). <=0 disables monitoring */
   #ifndef BOND_LINK_MON_INTERV
   #define BOND_LINK_MON_INTERV    0
   #endif
   
   #ifndef BOND_LINK_ARP_INTERV
   #define BOND_LINK_ARP_INTERV    0
   #endif
   
   #ifndef MAX_ARP_IP_TARGETS
   #define MAX_ARP_IP_TARGETS 16
   #endif
   
   struct bond_parm_tbl {
           char *modename;
           int mode;
   };
   
   static int arp_interval = BOND_LINK_ARP_INTERV;
   static char *arp_ip_target[MAX_ARP_IP_TARGETS] = { NULL, };
   static u32 arp_target[MAX_ARP_IP_TARGETS] = { 0, } ;
   static int arp_ip_count = 0;
   static u32 my_ip = 0;
   char *arp_target_hw_addr = NULL;
   
   static char *primary= NULL;
   
   static int app_abi_ver = 0;
   static int orig_app_abi_ver = -1; /* This is used to save the first ABI version
                                      * we receive from the application. Once set,
                                      * it won't be changed, and the module will
                                      * refuse to enslave/release interfaces if the
                                      * command comes from an application using
                                      * another ABI version.
                                      */
   
   static int max_bonds    = BOND_DEFAULT_MAX_BONDS;
   static int miimon       = BOND_LINK_MON_INTERV;
   static int use_carrier  = 1;
   static int bond_mode    = BOND_MODE_ROUNDROBIN;
   static int updelay      = 0;
   static int downdelay    = 0;
   
   static char *mode       = NULL;
   
   static struct bond_parm_tbl bond_mode_tbl[] = {
   {       "balance-rr",           BOND_MODE_ROUNDROBIN},
   {       "active-backup",        BOND_MODE_ACTIVEBACKUP},
   {       "balance-xor",          BOND_MODE_XOR},
   {       "broadcast",            BOND_MODE_BROADCAST},
   {       "802.3ad",              BOND_MODE_8023AD},
   {       "balance-tlb",          BOND_MODE_TLB},
   {       "balance-alb",          BOND_MODE_ALB},
   {       NULL,                   -1},
   };
   
   static int multicast_mode       = BOND_MULTICAST_ALL;
   static char *multicast          = NULL;
   
   static struct bond_parm_tbl bond_mc_tbl[] = {
   {       "disabled",             BOND_MULTICAST_DISABLED},
   {       "active",               BOND_MULTICAST_ACTIVE},
   {       "all",                  BOND_MULTICAST_ALL},
   {       NULL,                   -1},
   };
   
   static int lacp_fast            = 0;
   static char *lacp_rate          = NULL;
   
   static struct bond_parm_tbl bond_lacp_tbl[] = {
   {       "slow",         AD_LACP_SLOW},
   {       "fast",         AD_LACP_FAST},
   {       NULL,           -1},
   };
   
   static int first_pass   = 1;
   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(use_carrier, "i");
   MODULE_PARM_DESC(use_carrier, "Use netif_carrier_ok (vs MII ioctls) in miimon; 0 for off, 1 for on (default)");
   MODULE_PARM(mode, "s");
   MODULE_PARM_DESC(mode, "Mode of operation : 0 for round robin, 1 for active-backup, 2 for xor");
   MODULE_PARM(arp_interval, "i");
   MODULE_PARM_DESC(arp_interval, "arp interval in milliseconds");
   MODULE_PARM(arp_ip_target, "1-" __MODULE_STRING(MAX_ARP_IP_TARGETS) "s");
   MODULE_PARM_DESC(arp_ip_target, "arp targets in n.n.n.n form");
   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");
   MODULE_PARM(primary, "s");
   MODULE_PARM_DESC(primary, "Primary network device to use");
   MODULE_PARM(multicast, "s");
   MODULE_PARM_DESC(multicast, "Mode for multicast support : 0 for none, 1 for active slave, 2 for all slaves (default)");
   MODULE_PARM(lacp_rate, "s");
   MODULE_PARM_DESC(lacp_rate, "LACPDU tx rate to request from 802.3ad partner (slow/fast)");
   
   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 loadbalance_arp_monitor(struct net_device *dev);
   static void activebackup_arp_monitor(struct net_device *dev);
   static int bond_event(struct notifier_block *this, unsigned long event, void *ptr);
   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_mc_update(bonding_t *bond, slave_t *new, slave_t *old);
   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);
   
   /* Caller must hold bond->ptrlock for write */
   static inline struct slave*
   bond_assign_current_slave(struct bonding *bond,struct slave *newslave)
   {
           if ((bond_mode == BOND_MODE_TLB) ||
               (bond_mode == BOND_MODE_ALB)) {
                   bond_alb_assign_current_slave(bond, newslave);
           } else {
                   bond->current_slave = newslave;
           }
   
           return bond->current_slave;
   }
   
   /* #define BONDING_DEBUG 1 */
   
   /* several macros */
   
   static void arp_send_all(slave_t *slave)
   {       
           int i; 
   
           for (i = 0; (i<MAX_ARP_IP_TARGETS) && arp_target[i]; i++) { 
                   arp_send(ARPOP_REQUEST, ETH_P_ARP, arp_target[i], slave->dev, 
                            my_ip, arp_target_hw_addr, slave->dev->dev_addr,
                            arp_target_hw_addr); 
           } 
   }
    
   
   static const char *
   bond_mode_name(void)
   {
           switch (bond_mode) {
           case BOND_MODE_ROUNDROBIN :
                   return "load balancing (round-robin)";
           case BOND_MODE_ACTIVEBACKUP :
                   return "fault-tolerance (active-backup)";
           case BOND_MODE_XOR :
                   return "load balancing (xor)";
           case BOND_MODE_BROADCAST :
                   return "fault-tolerance (broadcast)";
           case BOND_MODE_8023AD:
                   return "IEEE 802.3ad Dynamic link aggregation";
           case BOND_MODE_TLB:
                   return "transmit load balancing";
           case BOND_MODE_ALB:
                   return "adaptive load balancing";
           default:
                   return "unknown";
           }
   }
   
   static const char *
   multicast_mode_name(void)
   {
           switch(multicast_mode) {
           case BOND_MULTICAST_DISABLED :
                   return "disabled";
           case BOND_MULTICAST_ACTIVE :
                   return "active slave only";
           case BOND_MULTICAST_ALL :
                   return "all slaves";
           default :
                   return "unknown";
           }
   }
   
   void bond_set_slave_inactive_flags(slave_t *slave)
   {
           slave->state = BOND_STATE_BACKUP;
           slave->dev->flags |= IFF_NOARP;
   }
   
   void bond_set_slave_active_flags(slave_t *slave)
   {
           slave->state = BOND_STATE_ACTIVE;
           slave->dev->flags &= ~IFF_NOARP;
   }
   
   /*
    * This function counts and verifies the the number of attached
    * slaves, checking the count against the expected value (given that incr
    * is either 1 or -1, for add or removal of a slave).  Only
    * bond_xmit_xor() uses the slave_cnt value, but this is still a good
    * consistency check.
    */
   static inline void
   update_slave_cnt(bonding_t *bond, int incr)
   {
           slave_t *slave = NULL;
           int expect = bond->slave_cnt + incr;
   
           bond->slave_cnt = 0;
           for (slave = bond->prev; slave != (slave_t*)bond;
                slave = slave->prev) {
                   bond->slave_cnt++;
           }
   
           if (expect != bond->slave_cnt)
                   BUG();
   }
   
   /*
    * Set MAC.  Differs from eth_mac_addr in that we allow changes while
    * netif_running().
    */
   static int
   bond_set_mac_address(struct net_device *dev, void *p)
   {
           struct sockaddr *addr = p;
   
           memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
           return 0;
   }
   
   /* 
    * 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 bond->next, or NULL if not applicable.
    *
    * bond->lock held for writing by caller.
    */
   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 ? */
                           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;
                   }
           } 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;
                   }
           }
   
           update_slave_cnt(bond, -1);
   
           /* no need to hold ptrlock since bond lock is
            * already held for writing
            */
           if (slave == bond->current_slave) {
                   if ( bond->next != (slave_t *)bond) {  /* found one slave */
                           bond_assign_current_slave(bond, bond->next);
                   } else {
                           bond_assign_current_slave(bond, NULL);
                   }
           }
   
           return slave;
   }
   
   /*
    * This function attaches the slave <slave> to the list <bond>.
    *
    * bond->lock held for writing by caller.
    */
   static void
   bond_attach_slave(struct bonding *bond, struct slave *new_slave)
   {
           /* 
            * 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;
   
           update_slave_cnt(bond, 1);
   }
   
   
   /*
    * Less bad way to call ioctl from within the kernel; this needs to be
    * done some other way to get the call out of interrupt context.
    * Needs "ioctl" variable to be supplied by calling context.
    */
   #define IOCTL(dev, arg, cmd) ({         \
           int ret;                        \
           mm_segment_t fs = get_fs();     \
           set_fs(get_ds());               \
           ret = ioctl(dev, arg, cmd);     \
           set_fs(fs);                     \
           ret; })
   
   /*
    * Get link speed and duplex from the slave's base driver
    * using ethtool. If for some reason the call fails or the
    * values are invalid, fake speed and duplex to 100/Full
    * and return error.
    */
   static int bond_update_speed_duplex(struct slave *slave)
   {
           struct net_device *dev = slave->dev;
           static int (* ioctl)(struct net_device *, struct ifreq *, int);
           struct ifreq ifr;
           struct ethtool_cmd etool;
   
           ioctl = dev->do_ioctl;
           if (ioctl) {
                   etool.cmd = ETHTOOL_GSET;
                   ifr.ifr_data = (char*)&etool;
                   if (IOCTL(dev, &ifr, SIOCETHTOOL) == 0) {
                           slave->speed = etool.speed;
                           slave->duplex = etool.duplex;
                   } else {
                           goto err_out;
                   }
           } else {
                   goto err_out;
           }
   
           switch (slave->speed) {
                   case SPEED_10:
                   case SPEED_100:
                   case SPEED_1000:
                           break;
                   default:
                           goto err_out;
           }
   
           switch (slave->duplex) {
                   case DUPLEX_FULL:
                   case DUPLEX_HALF:
                           break;
                   default:
                           goto err_out;
           }
   
           return 0;
   
   err_out:
           /* Fake speed and duplex */
           slave->speed = SPEED_100;
           slave->duplex = DUPLEX_FULL;
           return -1;
   }
   
   /* 
    * if <dev> supports MII link status reporting, check its link status.
    *
    * We either do MII/ETHTOOL ioctls, or check netif_carrier_ok(),
    * depening upon the setting of the use_carrier parameter.
    *
    * Return either BMSR_LSTATUS, meaning that the link is up (or we
    * can't tell and just pretend it is), or 0, meaning that the link is
    * down.
    *
    * If reporting is non-zero, instead of faking link up, return -1 if
    * both ETHTOOL and MII ioctls fail (meaning the device does not
    * support them).  If use_carrier is set, return whatever it says.
    * It'd be nice if there was a good way to tell if a driver supports
    * netif_carrier, but there really isn't.
    */
   static int
   bond_check_dev_link(struct net_device *dev, int reporting)
   {
           static int (* ioctl)(struct net_device *, struct ifreq *, int);
           struct ifreq ifr;
           struct mii_ioctl_data *mii;
           struct ethtool_value etool;
   
           if (use_carrier) {
                   return netif_carrier_ok(dev) ? BMSR_LSTATUS : 0;
           }
   
           ioctl = dev->do_ioctl;
           if (ioctl) {
                   /* TODO: set pointer to correct ioctl on a per team member */
                   /*       bases to make this more efficient. that is, once  */
                   /*       we determine the correct ioctl, we will always    */
                   /*       call it and not the others for that team          */
                   /*       member.                                           */
   
                   /*
                    * We cannot assume that SIOCGMIIPHY will also read a
                    * register; not all network drivers (e.g., e100)
                    * support that.
                    */
   
                   /* Yes, the mii is overlaid on the ifreq.ifr_ifru */
                   mii = (struct mii_ioctl_data *)&ifr.ifr_data;
                   if (IOCTL(dev, &ifr, SIOCGMIIPHY) == 0) {
                           mii->reg_num = MII_BMSR;
                           if (IOCTL(dev, &ifr, SIOCGMIIREG) == 0) {
                                   return mii->val_out & BMSR_LSTATUS;
                           }
                   }
   
                   /* try SIOCETHTOOL ioctl, some drivers cache ETHTOOL_GLINK */
                   /* for a period of time so we attempt to get link status   */
                   /* from it last if the above MII ioctls fail...            */
                   etool.cmd = ETHTOOL_GLINK;
                   ifr.ifr_data = (char*)&etool;
                   if (IOCTL(dev, &ifr, SIOCETHTOOL) == 0) {
                           if (etool.data == 1) {
                                   return BMSR_LSTATUS;
                           } else { 
   #ifdef BONDING_DEBUG
                                   printk(KERN_INFO 
                                           ":: SIOCETHTOOL shows link down \n");
   #endif
                                   return 0;
                           } 
                   }
   
           }
    
           /*
            * If reporting, report that either there's no dev->do_ioctl,
            * or both SIOCGMIIREG and SIOCETHTOOL failed (meaning that we
            * cannot report link status).  If not reporting, pretend
            * we're ok.
            */
           return reporting ? -1 : BMSR_LSTATUS;
   }
   
   static u16 bond_check_mii_link(bonding_t *bond)
   {
           int has_active_interface = 0;
   
           read_lock_bh(&bond->lock);
           read_lock(&bond->ptrlock);
           has_active_interface = (bond->current_slave != NULL);
           read_unlock(&bond->ptrlock);
           read_unlock_bh(&bond->lock);
   
           return (has_active_interface ? BMSR_LSTATUS : 0);
   }
   
   /* register to receive lacpdus on a bond */
   static void bond_register_lacpdu(struct bonding *bond)
   {
           struct packet_type* pk_type = &(BOND_AD_INFO(bond).ad_pkt_type);
   
           /* initialize packet type */
           pk_type->type = PKT_TYPE_LACPDU;
           pk_type->dev = bond->device;
           pk_type->func = bond_3ad_lacpdu_recv;
           pk_type->data = (void*)1;  /* understand shared skbs */
   
           dev_add_pack(pk_type);
   }
   
   /* unregister to receive lacpdus on a bond */
   static void bond_unregister_lacpdu(struct bonding *bond)
   {
           dev_remove_pack(&(BOND_AD_INFO(bond).ad_pkt_type));
   }
   
   static int bond_open(struct net_device *dev)
   {
           struct bonding *bond = (struct bonding *)(dev->priv);
           struct timer_list *timer = &((struct bonding *)(dev->priv))->mii_timer;
           struct timer_list *arp_timer = &((struct bonding *)(dev->priv))->arp_timer;
   
           if ((bond_mode == BOND_MODE_TLB) ||
               (bond_mode == BOND_MODE_ALB)) {
                   struct timer_list *alb_timer = &(BOND_ALB_INFO(bond).alb_timer);
   
                   /* bond_alb_initialize must be called before the timer
                    * is started.
                    */
                   if (bond_alb_initialize(bond, (bond_mode == BOND_MODE_ALB))) {
                           /* something went wrong - fail the open operation */
                           return -1;
                   }
   
                   init_timer(alb_timer);
                   alb_timer->expires  = jiffies + 1;
                   alb_timer->data     = (unsigned long)bond;
                   alb_timer->function = (void *)&bond_alb_monitor;
                   add_timer(alb_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;
                  if (bond_mode == BOND_MODE_ACTIVEBACKUP) {
                          arp_timer->function = (void *)&activebackup_arp_monitor;
                  } else {
                          arp_timer->function = (void *)&loadbalance_arp_monitor;
                  }
                  add_timer(arp_timer);
          }
  
          if (bond_mode == BOND_MODE_8023AD) {
                  struct timer_list *ad_timer = &(BOND_AD_INFO(bond).ad_timer);
                  init_timer(ad_timer);
                  ad_timer->expires  = jiffies + (AD_TIMER_INTERVAL * HZ / 1000);
                  ad_timer->data     = (unsigned long)bond;
                  ad_timer->function = (void *)&bond_3ad_state_machine_handler;
                  add_timer(ad_timer);
  
                  /* register to receive LACPDUs */
                  bond_register_lacpdu(bond);
          }
  
          return 0;
  }
  
  static int bond_close(struct net_device *master)
  {
          bonding_t *bond = (struct bonding *) master->priv;
  
          write_lock_bh(&bond->lock);
  
          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);
                  if (arp_target_hw_addr != NULL) {
                          kfree(arp_target_hw_addr); 
                          arp_target_hw_addr = NULL;
                  }
          }
  
          if (bond_mode == BOND_MODE_8023AD) {
                  del_timer_sync(&(BOND_AD_INFO(bond).ad_timer));
  
                  /* Unregister the receive of LACPDUs */
                  bond_unregister_lacpdu(bond);
          }
  
          bond_mc_list_destroy (bond);
  
          write_unlock_bh(&bond->lock);
  
          /* Release the bonded slaves */
          bond_release_all(master);
  
          if ((bond_mode == BOND_MODE_TLB) ||
              (bond_mode == BOND_MODE_ALB)) {
                  del_timer_sync(&(BOND_ALB_INFO(bond).alb_timer));
  
                  bond_alb_deinitialize(bond);
          }
  
          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);
  
          if (bond_mode == BOND_MODE_8023AD) {
                  /* del lacpdu mc addr from mc list */
                  u8 lacpdu_multicast[ETH_ALEN] = MULTICAST_LACPDU_ADDR;
  
                  dev_mc_delete(dev, lacpdu_multicast, ETH_ALEN, 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;
          switch (multicast_mode) {
          case BOND_MULTICAST_ACTIVE :
                  /* write lock already acquired */
                  if (bond->current_slave != NULL)
                          dev_mc_add(bond->current_slave->dev, addr, alen, 0);
                  break;
          case BOND_MULTICAST_ALL :
                  for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                          dev_mc_add(slave->dev, addr, alen, 0);
                  break;
          case BOND_MULTICAST_DISABLED :
                  break;
          }
  } 
  
  /*
   * 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; 
          switch (multicast_mode) {
          case BOND_MULTICAST_ACTIVE :
                  /* write lock already acquired */
                  if (bond->current_slave != NULL)
                          dev_mc_delete(bond->current_slave->dev, addr, alen, 0);
                  break;
          case BOND_MULTICAST_ALL :
                  for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                          dev_mc_delete(slave->dev, addr, alen, 0);
                  break;
          case BOND_MULTICAST_DISABLED :
                  break;
          }
  } 
  
  /*
   * 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; 
          switch (multicast_mode) {
          case BOND_MULTICAST_ACTIVE :
                  /* write lock already acquired */
                  if (bond->current_slave != NULL)
                          dev_set_promiscuity(bond->current_slave->dev, inc);
                  break;
          case BOND_MULTICAST_ALL :
                  for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                          dev_set_promiscuity(slave->dev, inc);
                  break;
          case BOND_MULTICAST_DISABLED :
                  break;
          }
  } 
  
  /*
   * Push the allmulti flag down to all slaves
   */
  static void bond_set_allmulti(bonding_t *bond, int inc)
  { 
          slave_t *slave; 
          switch (multicast_mode) {
          case BOND_MULTICAST_ACTIVE : 
                  /* write lock already acquired */
                  if (bond->current_slave != NULL)
                          dev_set_allmulti(bond->current_slave->dev, inc);
                  break;
          case BOND_MULTICAST_ALL :
                  for (slave = bond->prev; slave != (slave_t*)bond; slave = slave->prev)
                          dev_set_allmulti(slave->dev, inc);
                  break;
          case BOND_MULTICAST_DISABLED :
                  break;
          }
  } 
  
  /* 
   * 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;
  
          if (multicast_mode == BOND_MULTICAST_DISABLED)
                  return;
          /*
           * Lock the private data for the master
           */
          write_lock_bh(&bond->lock);
  
          /* 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_ATOMIC);
  
          write_unlock_bh(&bond->lock);
  }
  
  /*
   * Update the mc list and multicast-related flags for the new and 
   * old active slaves (if any) according to the multicast mode
   */
  static void bond_mc_update(bonding_t *bond, slave_t *new, slave_t *old)
  {
          struct dev_mc_list *dmi;
  
          switch(multicast_mode) {
          case BOND_MULTICAST_ACTIVE :            
                  if (bond->device->flags & IFF_PROMISC) {
                          if (old != NULL && new != old)
                                  dev_set_promiscuity(old->dev, -1);
                          dev_set_promiscuity(new->dev, 1);
                  }
                  if (bond->device->flags & IFF_ALLMULTI) {
                          if (old != NULL && new != old)
                                  dev_set_allmulti(old->dev, -1);
                          dev_set_allmulti(new->dev, 1);
                  }
                  /* first remove all mc addresses from old slave if any,
                     and _then_ add them to new active slave */
                  if (old != NULL && new != old) {
                          for (dmi = bond->device->mc_list; dmi != NULL; dmi = dmi->next)
                                  dev_mc_delete(old->dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
                  }
                  for (dmi = bond->device->mc_list; dmi != NULL; dmi = dmi->next)
                          dev_mc_add(new->dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
                  break;
          case BOND_MULTICAST_ALL :
                  /* nothing to do: mc list is already up-to-date on all slaves */
                  break;
          case BOND_MULTICAST_DISABLED :
                  break;
          }
  }
  
  /* 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 rflags = 0;
          int err = 0;
          struct dev_mc_list *dmi;
          struct in_ifaddr **ifap;
          struct in_ifaddr *ifa;
          int link_reporting;
          struct sockaddr addr;
  
          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);
          }
  
  
          /* bond must be initialized by bond_open() before enslaving */
          if (!(master_dev->flags & IFF_UP)) {
  #ifdef BONDING_DEBUG
                  printk(KERN_CRIT "Error, master_dev is not up\n");
  #endif
                  return -EPERM;
          }
  
          /* 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
                  return -EBUSY;
          }
  
          if (app_abi_ver >= 1) {
                  /* The application is using an ABI, which requires the
                   * slave interface to be closed.
                   */
                  if ((slave_dev->flags & IFF_UP)) {
  #ifdef BONDING_DEBUG
                          printk(KERN_CRIT "Error, slave_dev is up\n");
  #endif
                          return -EPERM;
                  }
  
                  if (slave_dev->set_mac_address == NULL) {
                          printk(KERN_CRIT
                                 "The slave device you specified does not support"
                                 " setting the MAC address.\n");
                          printk(KERN_CRIT
                                 "Your kernel likely does not support slave"
                                 " devices.\n");
  
                          return -EOPNOTSUPP;
                  }
          } else {
                  /* The application is not using an ABI, which requires the
                   * slave interface to be open.
                   */
                  if (!(slave_dev->flags & IFF_UP)) {
  #ifdef BONDING_DEBUG
                          printk(KERN_CRIT "Error, slave_dev is not running\n");
  #endif
                          return -EINVAL;
                  }
  
                  if ((bond_mode == BOND_MODE_8023AD) ||
                      (bond_mode == BOND_MODE_TLB) ||
                      (bond_mode == BOND_MODE_ALB)) {
                          printk(KERN_ERR
                                 "bonding: Error: to use %s mode, you must "
                                 "upgrade ifenslave.\n", bond_mode_name());
                          return -EOPNOTSUPP;
                  }
          }
  
          if ((new_slave = kmalloc(sizeof(slave_t), GFP_KERNEL)) == NULL) {
                  return -ENOMEM;
          }
          memset(new_slave, 0, sizeof(slave_t));
  
          /* save slave's original flags before calling
           * netdev_set_master and dev_open
           */
          new_slave->original_flags = slave_dev->flags;
  
          if (app_abi_ver >= 1) {
                  /* save slave's original ("permanent") mac address for
                   * modes that needs it, and for restoring it upon release,
                   * and then set it to the master's address
                   */
                  memcpy(new_slave->perm_hwaddr, slave_dev->dev_addr, ETH_ALEN);
  
                  if (bond->slave_cnt > 0) {
                          /* set slave to master's mac address
                           * The application already set the master's
                           * mac address to that of the first slave
                           */
                          memcpy(addr.sa_data, master_dev->dev_addr, ETH_ALEN);
                          addr.sa_family = slave_dev->type;
                          err = slave_dev->set_mac_address(slave_dev, &addr);
                          if (err) {
  #ifdef BONDING_DEBUG
                                  printk(KERN_CRIT "Error %d calling set_mac_address\n", err);
  #endif
                                  goto err_free;
                          }
                  }
  
                  /* open the slave since the application closed it */
                  err = dev_open(slave_dev);
                  if (err) {
  #ifdef BONDING_DEBUG
                          printk(KERN_CRIT "Openning slave %s failed\n", slave_dev->name);
  #endif
                          goto err_restore_mac;
                  }
          }
  
          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
                  if (app_abi_ver < 1) {
                          goto err_free;
                  } else {
                          goto err_close;
                  }
          }
  
          new_slave->dev = slave_dev;
  
          if ((bond_mode == BOND_MODE_TLB) ||
              (bond_mode == BOND_MODE_ALB)) {
                  /* bond_alb_init_slave() must be called before all other stages since
                   * it might fail and we do not want to have to undo everything
                   */
                  err = bond_alb_init_slave(bond, new_slave);
                  if (err) {
                          goto err_unset_master;
                  }
          }
  
          if (multicast_mode == BOND_MULTICAST_ALL) {
                  /* 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);
          }
  
          if (bond_mode == BOND_MODE_8023AD) {
                  /* add lacpdu mc addr to mc list */
                  u8 lacpdu_multicast[ETH_ALEN] = MULTICAST_LACPDU_ADDR;
  
                  dev_mc_add(slave_dev, lacpdu_multicast, ETH_ALEN, 0);
          }
  
          write_lock_bh(&bond->lock);
          
          bond_attach_slave(bond, new_slave);
          new_slave->delay = 0;
          new_slave->link_failure_count = 0;
  
          if (miimon > 0 && !use_carrier) {
                  link_reporting = bond_check_dev_link(slave_dev, 1);
  
                  if ((link_reporting == -1) && (arp_interval == 0)) {
                          /*
                           * miimon is set but a bonded network driver
                           * does not support ETHTOOL/MII and
                           * arp_interval is not set.  Note: if
                           * use_carrier is enabled, we will never go
                           * here (because netif_carrier is always
                           * supported); thus, we don't need to change
                           * the messages for netif_carrier.
                           */ 
                          printk(KERN_ERR
                                  "bond_enslave(): MII and ETHTOOL support not "
                                  "available for interface %s, and "
                                  "arp_interval/arp_ip_target module parameters "
                                  "not specified, thus bonding will not detect "
                                  "link failures! see bonding.txt for details.\n",
                                  slave_dev->name);
                  } else if (link_reporting == -1) {
                          /* unable  get link status using mii/ethtool */
                          printk(KERN_WARNING 
                                 "bond_enslave: can't get link status from "
                                 "interface %s; the network driver associated "
                                 "with this interface does not support "
                                 "MII or ETHTOOL link status reporting, thus "
                                 "miimon has no effect on this interface.\n", 
                                 slave_dev->name);
                  }
          }
  
          /* check for initial state */
          if ((miimon <= 0) ||
              (bond_check_dev_link(slave_dev, 0) == BMSR_LSTATUS)) {
                  if (updelay) {
  #ifdef BONDING_DEBUG
                          printk(KERN_CRIT "Initial state of slave_dev is "
                                 "BOND_LINK_BACK\n");
  #endif
                          new_slave->link  = BOND_LINK_BACK;
                          new_slave->delay = updelay;
                  }
                  else {
  #ifdef BONDING_DEBUG
                          printk(KERN_DEBUG "Initial state of slave_dev is "
                                  "BOND_LINK_UP\n");
  #endif
                          new_slave->link  = BOND_LINK_UP;
                  }
                  new_slave->jiffies = jiffies;
          }
          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 (bond_update_speed_duplex(new_slave) &&
              (new_slave->link != BOND_LINK_DOWN)) {
  
                  printk(KERN_WARNING
                         "bond_enslave(): failed to get speed/duplex from %s, "
                         "speed forced to 100Mbps, duplex forced to Full.\n",
                         new_slave->dev->name);
                  if (bond_mode == BOND_MODE_8023AD) {
                          printk(KERN_WARNING
                                 "Operation of 802.3ad mode requires ETHTOOL support "
                                 "in base driver for proper aggregator selection.\n");
                  }
          }
  
          /* 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 (bond_mode == BOND_MODE_ACTIVEBACKUP) {
                  if (((bond->current_slave == NULL)
                          || (bond->current_slave->dev->flags & IFF_NOARP))
                          && (new_slave->link != BOND_LINK_DOWN)) {
  #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_assign_current_slave(bond, new_slave);
                          bond_set_slave_active_flags(new_slave);
                          bond_mc_update(bond, new_slave, NULL);
                  }
                  else {
  #ifdef BONDING_DEBUG
                          printk(KERN_CRIT "This is just a backup slave\n");
  #endif
                          bond_set_slave_inactive_flags(new_slave);
                  }
                  if (((struct in_device *)slave_dev->ip_ptr) != NULL) {
                          read_lock_irqsave(&(((struct in_device *)slave_dev->ip_ptr)->lock), rflags);
                          ifap= &(((struct in_device *)slave_dev->ip_ptr)->ifa_list);
                          ifa = *ifap;
                          if (ifa != NULL)
                                  my_ip = ifa->ifa_address;
                          read_unlock_irqrestore(&(((struct in_device *)slave_dev->ip_ptr)->lock), rflags);
                  }
  
                  /* if there is a primary slave, remember it */
                  if (primary != NULL) {
                          if (strcmp(primary, new_slave->dev->name) == 0) {
                                  bond->primary_slave = new_slave;
                          }
                  }
          } else if (bond_mode == BOND_MODE_8023AD) {
                  /* in 802.3ad mode, the internal mechanism
                   * will activate the slaves in the selected
                   * aggregator
                   */
                  bond_set_slave_inactive_flags(new_slave);
                  /* if this is the first slave */
                  if (new_slave == bond->next) {
                          SLAVE_AD_INFO(new_slave).id = 1;
                          /* Initialize AD with the number of times that the AD timer is called in 1 second
                           * can be called only after the mac address of the bond is set
                           */
                          bond_3ad_initialize(bond, 1000/AD_TIMER_INTERVAL,
                                              lacp_fast);
                  } else {
                          SLAVE_AD_INFO(new_slave).id =
                          SLAVE_AD_INFO(new_slave->prev).id + 1;
                  }
  
                  bond_3ad_bind_slave(new_slave);
          } else if ((bond_mode == BOND_MODE_TLB) ||
                     (bond_mode == BOND_MODE_ALB)) {
                  new_slave->state = BOND_STATE_ACTIVE;
                  if ((bond->current_slave == NULL) && (new_slave->link != BOND_LINK_DOWN)) {
                          /* first slave or no active slave yet, and this link
                           * is OK, so make this interface the active one
                           */
                          bond_assign_current_slave(bond, new_slave);
                  }
  
                  /* if there is a primary slave, remember it */
                  if (primary != NULL) {
                          if (strcmp(primary, new_slave->dev->name) == 0) {
                                  bond->primary_slave = 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_assign_current_slave(bond, new_slave);
          }
  
          write_unlock_bh(&bond->lock);
  
          if (app_abi_ver < 1) {
                  /*
                   * !!! 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.
                   */
                  int ndx = 0;
  
                  for (ndx = 0; ndx < slave_dev->addr_len; ndx++) {
  #ifdef BONDING_DEBUG
                          printk(KERN_DEBUG
                                 "Checking ndx=%d of master_dev->dev_addr\n", ndx);
  #endif
                          if (master_dev->dev_addr[ndx] != 0) {
  #ifdef BONDING_DEBUG
                                  printk(KERN_DEBUG
                                         "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_DEBUG "%s doesn't have a MAC address yet.  ",
                                 master_dev->name);
                          printk(KERN_DEBUG "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_DOWN ? "n up" : " down");
  
          /* enslave is successful */
          return 0;
  
  /* Undo stages on error */
  err_unset_master:
          netdev_set_master(slave_dev, NULL);
  
  err_close:
          dev_close(slave_dev);
  
  err_restore_mac:
          memcpy(addr.sa_data, new_slave->perm_hwaddr, ETH_ALEN);
          addr.sa_family = slave_dev->type;
          slave_dev->set_mac_address(slave_dev, &addr);
  
  err_free:
          kfree(new_slave);
          return err;
  }
  
  /* 
   * 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;
          int ret = 0;
  
          if (master_dev == NULL || slave_dev == NULL) {
                  return -ENODEV;
          }
  
          bond = (struct bonding *) master_dev->priv;
          write_lock_bh(&bond->lock);
          slave = (slave_t *)bond;
          oldactive = bond->current_slave;
  
          while ((slave = slave->prev) != (slave_t *)bond) {
                  if(slave_dev == slave->dev) {
                          newactive = slave;
                          break;
                  }
          }
  
          /*
           * Changing to the current active: do nothing; return success.
           */
          if (newactive && (newactive == oldactive)) {
                  write_unlock_bh(&bond->lock);
                  return 0;
          }
  
          if ((newactive != NULL)&&
              (oldactive != NULL)&&
              (newactive->link == BOND_LINK_UP)&&
              IS_UP(newactive->dev)) {
                  if (bond_mode == BOND_MODE_ACTIVEBACKUP) {
                          bond_set_slave_inactive_flags(oldactive);
                          bond_set_slave_active_flags(newactive);
                  }
  
                  bond_mc_update(bond, newactive, oldactive);
                  bond_assign_current_slave(bond, newactive);
                  printk("%s : activate %s(old : %s)\n",
                          master_dev->name, newactive->dev->name, 
                          oldactive->dev->name);
          } else {
                  ret = -EINVAL;
          }
          write_unlock_bh(&bond->lock);
          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: Caller must hold ptrlock for writing.
   */
  slave_t *change_active_interface(bonding_t *bond)
  {
          slave_t *newslave, *oldslave;
          slave_t *bestslave = NULL;
          int mintime;
  
          newslave = oldslave = bond->current_slave;
  
          if (newslave == NULL) { /* there were no active slaves left */
                  if (bond->next != (slave_t *)bond) {  /* found one slave */
                          newslave = bond_assign_current_slave(bond, bond->next);
                  } else {
  
                          printk (" but could not find any %s interface.\n",
                                  (bond_mode == BOND_MODE_ACTIVEBACKUP) ? "backup":"other");
                          bond_assign_current_slave(bond, NULL);
                          return NULL; /* still no slave, return NULL */
                  }
          } else if (bond_mode == BOND_MODE_ACTIVEBACKUP) {
                  /* make sure oldslave doesn't send arps - this could
                   * cause a ping-pong effect between interfaces since they
                   * would be able to tx arps - in active backup only one
                   * slave should be able to tx arps, and that should be
                   * the current_slave; the only exception is when all
                   * slaves have gone down, then only one non-current slave can
                   * send arps at a time; clearing oldslaves' mc list is handled
                   * later in this function.
                   */
                  bond_set_slave_inactive_flags(oldslave);
          }
  
          mintime = updelay;
  
          /* first try the primary link; if arping, a link must tx/rx traffic 
           * before it can be considered the current_slave - also, we would skip 
           * slaves between the current_slave and primary_slave that may be up 
           * and able to arp
           */
          if ((bond->primary_slave != NULL) && (arp_interval == 0)) {
                  if (IS_UP(bond->primary_slave->dev)) 
                          newslave = bond->primary_slave;
          }
  
          do {
                  if (IS_UP(newslave->dev)) {
                          if (newslave->link == BOND_LINK_UP) {
                                  /* this one is immediately usable */
                                  if (bond_mode == BOND_MODE_ACTIVEBACKUP) {
                                          bond_set_slave_active_flags(newslave);
                                          bond_mc_update(bond, newslave, oldslave);
                                          printk (" and making interface %s the active one.\n",
                                                  newslave->dev->name);
                                  }
                                  else {
                                          printk (" and setting pointer to interface %s.\n",
                                                  newslave->dev->name);
                                  }
  
                                  bond_assign_current_slave(bond, newslave);
                                  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;
                  bestslave->jiffies = jiffies;
                  bond_set_slave_active_flags(bestslave);
                  bond_mc_update(bond, bestslave, oldslave);
                  bond_assign_current_slave(bond, bestslave);
                  return bestslave;
          }
  
          if ((bond_mode == BOND_MODE_ACTIVEBACKUP) &&
              (multicast_mode == BOND_MULTICAST_ACTIVE) &&
              (oldslave != NULL)) {
                  /* flush bonds (master's) mc_list from oldslave since it wasn't
                   * updated (and deleted) above
                   */ 
                  bond_mc_list_flush(oldslave->dev, bond->device); 
                  if (bond->device->flags & IFF_PROMISC) {
                          dev_set_promiscuity(oldslave->dev, -1);
                  }
                  if (bond->device->flags & IFF_ALLMULTI) {
                          dev_set_allmulti(oldslave->dev, -1);
                  }
          }
  
          printk (" but could not find any %s interface.\n",
                  (bond_mode == BOND_MODE_ACTIVEBACKUP) ? "backup":"other");
          
          /* absolutely nothing found. let's return NULL */
          bond_assign_current_slave(bond, NULL);
          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;
          struct sockaddr addr;
          
          if (master == NULL || slave == NULL)  {
                  return -ENODEV;
          }
  
          bond = (struct bonding *) master->priv;
  
          /* 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);
                  return -EINVAL;
          }
  
          write_lock_bh(&bond->lock);
          bond->current_arp_slave = NULL;
          our_slave = (slave_t *)bond;
          old_current = bond->current_slave;
          while ((our_slave = our_slave->prev) != (slave_t *)bond) {
                  if (our_slave->dev == slave) {
                          int mac_addr_differ = memcmp(bond->device->dev_addr,
                                                   our_slave->perm_hwaddr,
                                                   ETH_ALEN);
                          if (!mac_addr_differ && (bond->slave_cnt > 1)) {
                                  printk(KERN_WARNING "WARNING: the permanent HWaddr of %s "
                                  "- %02X:%02X:%02X:%02X:%02X:%02X - "
                                  "is still in use by %s. Set the HWaddr "
                                  "of %s to a different address "
                                  "to avoid conflicts.\n",
                                         slave->name,
                                         slave->dev_addr[0],
                                         slave->dev_addr[1],
                                         slave->dev_addr[2],
                                         slave->dev_addr[3],
                                         slave->dev_addr[4],
                                         slave->dev_addr[5],
                                         bond->device->name,
                                         slave->name);
                          }
  
                          /* Inform AD package of unbinding of slave. */
                          if (bond_mode == BOND_MODE_8023AD) {
                                  /* must be called before the slave is
                                   * detached from the list
                                   */
                                  bond_3ad_unbind_slave(our_slave);
                          }
  
                          /* release the slave from its bond */
                          bond_detach_slave(bond, our_slave);
  
                          if (bond->primary_slave == our_slave) {
                                  bond->primary_slave = NULL;
                          }
  
                          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");
                          }
                          
                          if (bond->current_slave == NULL) {
                                  printk(KERN_INFO
                                          "%s: now running without any active interface !\n",
                                          master->name);
                          }
  
                          if ((bond_mode == BOND_MODE_TLB) ||
                              (bond_mode == BOND_MODE_ALB)) {
                                  /* must be called only after the slave has been
                                   * detached from the list and the current_slave
                                   * has been replaced (if our_slave == old_current)
                                   */
                                  bond_alb_deinit_slave(bond, our_slave);
                          }
  
                          break;
                  }
  
          }
          write_unlock_bh(&bond->lock);
          
          if (our_slave == (slave_t *)bond) {
                  /* if we get here, it's because the device was not found */
                  printk (KERN_INFO "%s: %s not enslaved\n", master->name, slave->name);
                  return -EINVAL;
          }
  
          /* undo settings and restore original values */
          
          if (multicast_mode == BOND_MULTICAST_ALL) {
                  /* 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);
  
          /* close slave before restoring its mac address */
          dev_close(slave);
  
          if (app_abi_ver >= 1) {
                  /* restore original ("permanent") mac address */
                  memcpy(addr.sa_data, our_slave->perm_hwaddr, ETH_ALEN);
                  addr.sa_family = slave->type;
                  slave->set_mac_address(slave, &addr);
          }
  
          /* restore the original state of the
           * IFF_NOARP flag that might have been
           * set by bond_set_slave_inactive_flags()
           */
          if ((our_slave->original_flags & IFF_NOARP) == 0) {
                  slave->flags &= ~IFF_NOARP;
          }
  
          kfree(our_slave);
  
          /* if the last slave was removed, zero the mac address
           * of the master so it will be set by the application
           * to the mac address of the first slave
           */
          if (bond->next == (slave_t*)bond) {
                  memset(master->dev_addr, 0, master->addr_len);
          }
  
          return 0;  /* deletion OK */
  }
  
  /* 
   * This function releases all slaves.
   */
  static int bond_release_all(struct net_device *master)
  {
          bonding_t *bond;
          slave_t *our_slave, *old_current;
          struct net_device *slave_dev;
          struct sockaddr addr;
          int err = 0;
  
          if (master == NULL)  {
                  return -ENODEV;
          }
  
          if (master->flags & IFF_SLAVE) {
                  return -EINVAL;
          }
  
          bond = (struct bonding *) master->priv;
  
          write_lock_bh(&bond->lock);
          if (bond->next == (struct slave *) bond) {
                  err = -EINVAL;
                  goto out;
          }
  
          old_current = bond->current_slave;
          bond_assign_current_slave(bond, NULL);
          bond->current_arp_slave = NULL;
          bond->primary_slave = NULL;
  
          while ((our_slave = bond->prev) != (slave_t *)bond) {
                  /* Inform AD package of unbinding of slave
                   * before slave is detached from the list.
                   */
                  if (bond_mode == BOND_MODE_8023AD) {
                          bond_3ad_unbind_slave(our_slave);
                  }
  
                  slave_dev = our_slave->dev;
                  bond_detach_slave(bond, our_slave);
  
                  if ((bond_mode == BOND_MODE_TLB) ||
                      (bond_mode == BOND_MODE_ALB)) {
                          /* must be called only after the slave
                           * has been detached from the list
                           */
                          bond_alb_deinit_slave(bond, our_slave);
                  }
  
                  /* now that the slave is detached, unlock and perform
                   * all the undo steps that should not be called from
                   * within a lock.
                   */
                  write_unlock_bh(&bond->lock);
  
                  if (multicast_mode == BOND_MULTICAST_ALL 
                      || (multicast_mode == BOND_MULTICAST_ACTIVE 
                          && old_current == our_slave)) {
  
                          /* flush master's mc_list from slave */ 
                          bond_mc_list_flush (slave_dev, master); 
  
                          /* unset promiscuity level from slave */
                          if (master->flags & IFF_PROMISC) 
                                  dev_set_promiscuity(slave_dev, -1); 
  
                          /* unset allmulti level from slave */ 
                          if (master->flags & IFF_ALLMULTI)
                                  dev_set_allmulti(slave_dev, -1); 
                  }
  
                  netdev_set_master(slave_dev, NULL);
  
                  /* close slave before restoring its mac address */
                  dev_close(slave_dev);
  
                  if (app_abi_ver >= 1) {
                          /* restore original ("permanent") mac address*/
                          memcpy(addr.sa_data, our_slave->perm_hwaddr, ETH_ALEN);
                          addr.sa_family = slave_dev->type;
                          slave_dev->set_mac_address(slave_dev, &addr);
                  }
  
                  /* restore the original state of the IFF_NOARP flag that might have
                   * been set by bond_set_slave_inactive_flags()
                   */
                  if ((our_slave->original_flags & IFF_NOARP) == 0) {
                          slave_dev->flags &= ~IFF_NOARP;
                  }
  
                  kfree(our_slave);
  
                  /* re-acquire the lock before getting the next slave */
                  write_lock_bh(&bond->lock);
          }
  
          /* zero the mac address of the master so it will be
           * set by the application to the mac address of the
           * first slave
           */
          memset(master->dev_addr, 0, master->addr_len);
  
          printk (KERN_INFO "%s: released all slaves\n", master->name);
  
  out:
          write_unlock_bh(&bond->lock);
  
          return err;
  }
  
  /* 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;
          int slave_died = 0;
  
          read_lock(&bond->lock);
  
          /* 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;
                  int link_state;
                  u16 old_speed = slave->speed;
                  u8 old_duplex = slave->duplex;
                  
                  link_state = bond_check_dev_link(dev, 0);
  
                  switch (slave->link) {
                  case BOND_LINK_UP:      /* the link was up */
                          if (link_state == BMSR_LSTATUS) {
                                  /* 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)
                                                  ? ((bond_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 != BMSR_LSTATUS) {
                                  /* 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 ((bond_mode == BOND_MODE_ACTIVEBACKUP) ||
                                              (bond_mode == BOND_MODE_8023AD)) {
                                                  bond_set_slave_inactive_flags(slave);
                                          }
                                          printk(KERN_INFO
                                                  "%s: link status definitely down "
                                                  "for interface %s, disabling it",
                                                  master->name,
                                                  dev->name);
  
                                          /* notify ad that the link status has changed */
                                          if (bond_mode == BOND_MODE_8023AD) {
                                                  bond_3ad_handle_link_change(slave, BOND_LINK_DOWN);
                                          }
  
                                          if ((bond_mode == BOND_MODE_TLB) ||
                                              (bond_mode == BOND_MODE_ALB)) {
                                                  bond_alb_handle_link_change(bond, slave, BOND_LINK_DOWN);
                                          }
  
                                          write_lock(&bond->ptrlock);
                                          if (slave == bond->current_slave) {
                                                  /* find a new interface and be verbose */
                                                  change_active_interface(bond);
                                          } else {
                                                  printk(".\n");
                                          }
                                          write_unlock(&bond->ptrlock);
                                          slave_died = 1;
                                  } else {
                                          slave->delay--;
                                  }
                          } else {
                                  /* link up again */
                                  slave->link  = BOND_LINK_UP;
                                  slave->jiffies = jiffies;
                                  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 != BMSR_LSTATUS) {
                                  /* 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 != BMSR_LSTATUS) {
                                  /* 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 {
                                  /* link stays up */
                                  if (slave->delay == 0) {
                                          /* now the link has been up for long time enough */
                                          slave->link = BOND_LINK_UP;
                                          slave->jiffies = jiffies;
  
                                          if (bond_mode == BOND_MODE_8023AD) {
                                                  /* prevent it from being the active one */
                                                  slave->state = BOND_STATE_BACKUP;
                                          }
                                          else if (bond_mode != BOND_MODE_ACTIVEBACKUP) {
                                                  /* make it immediately active */
                                                  slave->state = BOND_STATE_ACTIVE;
                                          } else if (slave != bond->primary_slave) {
                                                  /* prevent it from being the active one */
                                                  slave->state = BOND_STATE_BACKUP;
                                          }
  
                                          printk(KERN_INFO
                                                  "%s: link status definitely up "
                                                  "for interface %s.\n",
                                                  master->name,
                                                  dev->name);
          
                                          /* notify ad that the link status has changed */
                                          if (bond_mode == BOND_MODE_8023AD) {
                                                  bond_3ad_handle_link_change(slave, BOND_LINK_UP);
                                          }
  
                                          if ((bond_mode == BOND_MODE_TLB) ||
                                              (bond_mode == BOND_MODE_ALB)) {
                                                  bond_alb_handle_link_change(bond, slave, BOND_LINK_UP);
                                          }
  
                                          write_lock(&bond->ptrlock);
                                          if ( (bond->primary_slave != NULL)
                                            && (slave == bond->primary_slave) )
                                                  change_active_interface(bond); 
                                          write_unlock(&bond->ptrlock);
                                  }
                                  else
                                          slave->delay--;
  
                                  /* we'll also look for the mostly eligible slave */
                                  if (bond->primary_slave == NULL)  {
                                      if (IS_UP(dev) && (slave->delay < mindelay)) {
                                          mindelay = slave->delay;
                                          bestslave = slave;
                                      } 
                                  } else if ( (IS_UP(bond->primary_slave->dev))  || 
                                            ( (!IS_UP(bond->primary_slave->dev))  && 
                                            (IS_UP(dev) && (slave->delay < mindelay)) ) ) {
                                          mindelay = slave->delay;
                                          bestslave = slave;
                                  }
                          }
                          break;
                  } /* end of switch */
  
                  bond_update_speed_duplex(slave);
  
                  if (bond_mode == BOND_MODE_8023AD) {
                          if (old_speed != slave->speed) {
                                  bond_3ad_adapter_speed_changed(slave);
                          }
                          if (old_duplex != slave->duplex) {
                                  bond_3ad_adapter_duplex_changed(slave);
                          }
                  }
  
          } /* 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);
  
          /* no active interface at the moment or need to bring up the primary */
          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;
                                  bestslave->jiffies = jiffies;
  
                                  /* notify ad that the link status has changed */
                                  if (bond_mode == BOND_MODE_8023AD) {
                                          bond_3ad_handle_link_change(bestslave, BOND_LINK_UP);
                                  }
  
                                  if ((bond_mode == BOND_MODE_TLB) ||
                                      (bond_mode == BOND_MODE_ALB)) {
                                          bond_alb_handle_link_change(bond, bestslave, BOND_LINK_UP);
                                  }
                          }
  
                          if (bond_mode == BOND_MODE_ACTIVEBACKUP) {
                                  bond_set_slave_active_flags(bestslave);
                                  bond_mc_update(bond, bestslave, NULL);
                          } else if (bond_mode != BOND_MODE_8023AD) {
                                  bestslave->state = BOND_STATE_ACTIVE;
                          }
                          write_lock(&bond->ptrlock);
                          bond_assign_current_slave(bond, 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(&bond->lock);
          /* re-arm the timer */
          mod_timer(&bond->mii_timer, jiffies + (miimon * HZ / 1000));
  }
  
  /* 
   * this function is called regularly to monitor each slave's link 
   * ensuring that traffic is being sent and received when arp monitoring
   * is used in load-balancing mode. if the adapter has been dormant, then an 
   * arp is transmitted to generate traffic. see activebackup_arp_monitor for 
   * arp monitoring in active backup mode. 
   */
  static void loadbalance_arp_monitor(struct net_device *master)
  {
          bonding_t *bond;
          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;
          }
  
          /* TODO: investigate why rtnl_shlock_nowait and rtnl_exlock_nowait
           * are called below and add comment why they are required... 
           */
          if ((!IS_UP(master)) || rtnl_shlock_nowait()) {
                  mod_timer(&bond->arp_timer, next_timer);
                  return;
          }
  
          if (rtnl_exlock_nowait()) {
                  rtnl_shunlock();
                  mod_timer(&bond->arp_timer, next_timer);
                  return;
          }
  
          read_lock(&bond->lock);
  
          /* see if any of the previous devices are up now (i.e. they have
           * xmt and rcv traffic). the current_slave does not come into
           * the picture unless it is null. also, slave->jiffies is not needed
           * here because we send an arp on each slave and give a slave as
           * long as it needs to get the tx/rx within the delta.
           * TODO: what about up/down delay in arp mode? it wasn't here before
           *       so it can wait 
           */
          slave = (slave_t *)bond;
          while ((slave = slave->prev) != (slave_t *)bond)  {
  
                  if (slave->link != BOND_LINK_UP) {
  
                          if (((jiffies - slave->dev->trans_start) <= 
                                                  the_delta_in_ticks) &&  
                               ((jiffies - slave->dev->last_rx) <= 
                                                  the_delta_in_ticks)) {
  
                                  slave->link  = BOND_LINK_UP;
                                  slave->state = BOND_STATE_ACTIVE;
  
                                  /* primary_slave has no meaning in round-robin
                                   * mode. the window of a slave being up and 
                                   * current_slave being null after enslaving
                                   * is closed.
                                   */
                                  write_lock(&bond->ptrlock);
                                  if (bond->current_slave == NULL) {
                                          printk(KERN_INFO
                                                  "%s: link status definitely up "
                                                  "for interface %s, ",
                                                  master->name,
                                                  slave->dev->name);
                                          change_active_interface(bond); 
                                  } else {
                                          printk(KERN_INFO
                                                  "%s: interface %s is now up\n",
                                                  master->name,
                                                  slave->dev->name);
                                  }
                                  write_unlock(&bond->ptrlock);
                          } 
                  } else {
                          /* slave->link == BOND_LINK_UP */
  
                          /* not all switches will respond to an arp request
                           * when the source ip is 0, so don't take the link down
                           * if we don't know our ip yet
                           */
                          if (((jiffies - slave->dev->trans_start) >= 
                                (2*the_delta_in_ticks)) ||
                               (((jiffies - slave->dev->last_rx) >= 
                                 (2*the_delta_in_ticks)) && my_ip !=0)) {
                                  slave->link  = BOND_LINK_DOWN;
                                  slave->state = BOND_STATE_BACKUP;
                                  if (slave->link_failure_count < UINT_MAX) {
                                          slave->link_failure_count++;
                                  }
                                  printk(KERN_INFO
                                         "%s: interface %s is now down.\n",
                                         master->name,
                                         slave->dev->name);
  
                                  write_lock(&bond->ptrlock);
                                  if (slave == bond->current_slave) {
                                          change_active_interface(bond);
                                  }
                                  write_unlock(&bond->ptrlock);
                          }
                  } 
  
                  /* note: if switch is in round-robin mode, all links 
                   * must tx arp to ensure all links rx an arp - otherwise
                   * links may oscillate or not come up at all; if switch is 
                   * in something like xor mode, there is nothing we can 
                   * do - all replies will be rx'ed on same link causing slaves 
                   * to be unstable during low/no traffic periods
                   */
                  if (IS_UP(slave->dev)) {
                          arp_send_all(slave);
                  }
          }
  
          read_unlock(&bond->lock);
          rtnl_exunlock();
          rtnl_shunlock();
  
          /* re-arm the timer */
          mod_timer(&bond->arp_timer, next_timer);
  }
  
  /* 
   * When using arp monitoring in active-backup mode, this function is
   * called to determine if any backup slaves have went down or a new
   * current slave needs to be found.
   * The backup slaves never generate traffic, they are considered up by merely 
   * receiving traffic. If the current slave goes down, each backup slave will 
   * be given the opportunity to tx/rx an arp before being taken down - this 
   * prevents all slaves from being taken down due to the current slave not 
   * sending any traffic for the backups to receive. The arps are not necessarily
   * necessary, any tx and rx traffic will keep the current slave up. While any 
   * rx traffic will keep the backup slaves up, the current slave is responsible 
   * for generating traffic to keep them up regardless of any other traffic they 
   * may have received.
   * see loadbalance_arp_monitor for arp monitoring in load balancing mode
   */
  static void activebackup_arp_monitor(struct net_device *master)
  {
          bonding_t *bond;
          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;
          }
  
          if (!IS_UP(master)) {
                  mod_timer(&bond->arp_timer, next_timer);
                  return;
          }
  
          read_lock(&bond->lock);
  
          /* determine if any slave has come up or any backup slave has 
           * gone down 
           * TODO: what about up/down delay in arp mode? it wasn't here before
           *       so it can wait 
           */
          slave = (slave_t *)bond;
          while ((slave = slave->prev) != (slave_t *)bond)  {
  
                  if (slave->link != BOND_LINK_UP) {
                          if ((jiffies - slave->dev->last_rx) <=
                              the_delta_in_ticks) {
  
                                  slave->link = BOND_LINK_UP;
                                  write_lock(&bond->ptrlock);
                                  if ((bond->current_slave == NULL) &&
                                      ((jiffies - slave->dev->trans_start) <=
                                       the_delta_in_ticks)) {
                                          bond_assign_current_slave(bond, slave);
                                          bond_set_slave_active_flags(slave);
                                          bond_mc_update(bond, slave, NULL);
                                          bond->current_arp_slave = NULL;
                                  } else if (bond->current_slave != slave) {
                                          /* this slave has just come up but we 
                                           * already have a current slave; this
                                           * can also happen if bond_enslave adds
                                           * a new slave that is up while we are 
                                           * searching for a new slave
                                           */
                                          bond_set_slave_inactive_flags(slave);
                                          bond->current_arp_slave = NULL;
                                  }
  
                                  if (slave == bond->current_slave) {
                                          printk(KERN_INFO
                                                  "%s: %s is up and now the "
                                                  "active interface\n",
                                                  master->name,
                                                  slave->dev->name);
                                  } else {
                                          printk(KERN_INFO
                                                  "%s: backup interface %s is "
                                                  "now up\n",
                                                  master->name,
                                                  slave->dev->name);
                                  }
  
                                  write_unlock(&bond->ptrlock);
                          }
                  } else {
                          read_lock(&bond->ptrlock);
                          if ((slave != bond->current_slave) &&
                              (bond->current_arp_slave == NULL) &&
                              (((jiffies - slave->dev->last_rx) >=
                               3*the_delta_in_ticks) && (my_ip != 0))) {
                                  /* a backup slave has gone down; three times 
                                   * the delta allows the current slave to be 
                                   * taken out before the backup slave.
                                   * note: a non-null current_arp_slave indicates
                                   * the current_slave went down and we are 
                                   * searching for a new one; under this 
                                   * condition we only take the current_slave 
                                   * down - this gives each slave a chance to 
                                   * tx/rx traffic before being taken out
                                   */
                                  read_unlock(&bond->ptrlock);
                                  slave->link  = BOND_LINK_DOWN;
                                  if (slave->link_failure_count < UINT_MAX) {
                                          slave->link_failure_count++;
                                  }
                                  bond_set_slave_inactive_flags(slave);
                                  printk(KERN_INFO
                                          "%s: backup interface %s is now down\n",
                                          master->name,
                                          slave->dev->name);
                          } else {
                                  read_unlock(&bond->ptrlock);
                          }
                  }
          }
  
          read_lock(&bond->ptrlock);
          slave = bond->current_slave;
          read_unlock(&bond->ptrlock);
  
          if (slave != NULL) {
  
                  /* if we have sent traffic in the past 2*arp_intervals but
                   * haven't xmit and rx traffic in that time interval, select 
                   * a different slave. slave->jiffies is only updated when
                   * a slave first becomes the current_slave - not necessarily
                   * after every arp; this ensures the slave has a full 2*delta 
                   * before being taken out. if a primary is being used, check 
                   * if it is up and needs to take over as the current_slave
                   */
                  if ((((jiffies - slave->dev->trans_start) >= 
                         (2*the_delta_in_ticks)) ||
                       (((jiffies - slave->dev->last_rx) >= 
                         (2*the_delta_in_ticks)) && (my_ip != 0))) &&
                      ((jiffies - slave->jiffies) >= 2*the_delta_in_ticks)) {
  
                          slave->link  = BOND_LINK_DOWN;
                          if (slave->link_failure_count < UINT_MAX) {
                                  slave->link_failure_count++;
                          }
                          printk(KERN_INFO "%s: link status down for "
                                           "active interface %s, disabling it",
                                 master->name,
                                 slave->dev->name);
                          write_lock(&bond->ptrlock);
                          slave = change_active_interface(bond);
                          write_unlock(&bond->ptrlock);
                          bond->current_arp_slave = slave;
                          if (slave != NULL) {
                                  slave->jiffies = jiffies;
                          }
  
                  } else if ((bond->primary_slave != NULL) && 
                             (bond->primary_slave != slave) && 
                             (bond->primary_slave->link == BOND_LINK_UP)) {
                          /* at this point, slave is the current_slave */
                          printk(KERN_INFO 
                                 "%s: changing from interface %s to primary "
                                 "interface %s\n",
                                 master->name, 
                                 slave->dev->name, 
                                 bond->primary_slave->dev->name);
                                 
                          /* primary is up so switch to it */
                          bond_set_slave_inactive_flags(slave);
                          bond_mc_update(bond, bond->primary_slave, slave);
                          write_lock(&bond->ptrlock);
                          bond_assign_current_slave(bond, bond->primary_slave);
                          write_unlock(&bond->ptrlock);
                          slave = bond->primary_slave;
                          bond_set_slave_active_flags(slave);
                          slave->jiffies = jiffies;
                  } else {
                          bond->current_arp_slave = NULL;
                  }
  
                  /* the current slave must tx an arp to ensure backup slaves
                   * rx traffic
                   */
                  if ((slave != NULL) && (my_ip != 0)) {
                          arp_send_all(slave);
                  }
          }
  
          /* if we don't have a current_slave, search for the next available 
           * backup slave from the current_arp_slave and make it the candidate 
           * for becoming the current_slave
           */
          if (slave == NULL) { 
  
                  if ((bond->current_arp_slave == NULL) ||
                      (bond->current_arp_slave == (slave_t *)bond)) {
                          bond->current_arp_slave = bond->prev;
                  } 
  
                  if (bond->current_arp_slave != (slave_t *)bond) {
                          bond_set_slave_inactive_flags(bond->current_arp_slave);
                          slave = bond->current_arp_slave->next;
  
                          /* search for next candidate */
                          do {
                                  if (IS_UP(slave->dev)) {
                                          slave->link = BOND_LINK_BACK;
                                          bond_set_slave_active_flags(slave);
                                          arp_send_all(slave);
                                          slave->jiffies = jiffies;
                                          bond->current_arp_slave = slave;
                                          break;
                                  }
  
                                  /* if the link state is up at this point, we 
                                   * mark it down - this can happen if we have 
                                   * simultaneous link failures and 
                                   * change_active_interface doesn't make this 
                                   * one the current slave so it is still marked 
                                   * up when it is actually down
                                   */
                                  if (slave->link == BOND_LINK_UP) {
                                          slave->link  = BOND_LINK_DOWN;
                                          if (slave->link_failure_count < 
                                                          UINT_MAX) {
                                                  slave->link_failure_count++;
                                          }
  
                                          bond_set_slave_inactive_flags(slave);
                                          printk(KERN_INFO
                                                  "%s: backup interface "
                                                  "%s is now down.\n",
                                                  master->name,
                                                  slave->dev->name);
                                  }
                          } while ((slave = slave->next) != 
                                          bond->current_arp_slave->next);
                  }
          }
  
          read_unlock(&bond->lock);
          mod_timer(&bond->arp_timer, next_timer);
  }
  
  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;
  
          info->bond_mode = bond_mode;
          info->num_slaves = 0;
          info->miimon = miimon;
  
          read_lock_bh(&bond->lock);
          for (slave = bond->prev; slave != (slave_t *)bond; slave = slave->prev) {
                  info->num_slaves++;
          }
          read_unlock_bh(&bond->lock);
  
          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;
  
          if (info->slave_id < 0) {
                  return -ENODEV;
          }
  
          read_lock_bh(&bond->lock);
          for (slave = bond->prev; 
                   slave != (slave_t *)bond && cur_ndx < info->slave_id; 
                   slave = slave->prev) {
                  cur_ndx++;
          }
          read_unlock_bh(&bond->lock);
  
          if (slave != (slave_t *)bond) {
                  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_ethtool_ioctl(struct net_device *master_dev, struct ifreq *ifr)
  {
          void *addr = ifr->ifr_data;
          uint32_t cmd;
  
          if (get_user(cmd, (uint32_t *) addr))
                  return -EFAULT;
  
          switch (cmd) {
  
          case ETHTOOL_GDRVINFO:
                  {
                          struct ethtool_drvinfo info;
                          char *endptr;
  
                          if (copy_from_user(&info, addr, sizeof(info)))
                                  return -EFAULT;
  
                          if (strcmp(info.driver, "ifenslave") == 0) {
                                  int new_abi_ver;
  
                                  new_abi_ver = simple_strtoul(info.fw_version,
                                                               &endptr, 0);
                                  if (*endptr) {
                                          printk(KERN_ERR
                                                 "bonding: Error: got invalid ABI"
                                                 " version from application\n");
  
                                          return -EINVAL;
                                  }
  
                                  if (orig_app_abi_ver == -1) {
                                          orig_app_abi_ver  = new_abi_ver;
                                  }
  
                                  app_abi_ver = new_abi_ver;
                          }
  
                          strncpy(info.driver,  DRV_NAME, 32);
                          strncpy(info.version, DRV_VERSION, 32);
                          snprintf(info.fw_version, 32, "%d", BOND_ABI_VERSION);
  
                          if (copy_to_user(addr, &info, sizeof(info)))
                                  return -EFAULT;
  
                          return 0;
                  }
                  break;
          default:
                  return -EOPNOTSUPP;
          }
  }
  
  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;
          struct mii_ioctl_data *mii = NULL;
          int prev_abi_ver = orig_app_abi_ver;
          int ret = 0;
  
  #ifdef BONDING_DEBUG
          printk(KERN_INFO "bond_ioctl: master=%s, cmd=%d\n", 
                  master_dev->name, cmd);
  #endif
  
          switch (cmd) {
          case SIOCETHTOOL:
                  return bond_ethtool_ioctl(master_dev, ifr);
  
          case SIOCGMIIPHY:
                  mii = (struct mii_ioctl_data *)&ifr->ifr_data;
                  if (mii == NULL) {
                          return -EINVAL;
                  }
                  mii->phy_id = 0;
                  /* Fall Through */
          case SIOCGMIIREG:
                  /* 
                   * We do this again just in case we were called by SIOCGMIIREG
                   * instead of SIOCGMIIPHY.
                   */
                  mii = (struct mii_ioctl_data *)&ifr->ifr_data;
                  if (mii == NULL) {
                          return -EINVAL;
                  }
                  if (mii->reg_num == 1) {
                          mii->val_out = 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;
          }
  
          if (orig_app_abi_ver == -1) {
                  /* no orig_app_abi_ver was provided yet, so we'll use the
                   * current one from now on, even if it's 0
                   */
                  orig_app_abi_ver = app_abi_ver;
  
          } else if (orig_app_abi_ver != app_abi_ver) {
                  printk(KERN_ERR
                         "bonding: Error: already using ifenslave ABI "
                         "version %d; to upgrade ifenslave to version %d, "
                         "you must first reload bonding.\n",
                         orig_app_abi_ver, app_abi_ver);
                  return -EINVAL;
          }
  
          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 ((bond_mode == BOND_MODE_ACTIVEBACKUP) ||
                              (bond_mode == BOND_MODE_TLB) ||
                              (bond_mode == BOND_MODE_ALB)) {
                                  ret = bond_change_active(master_dev, slave_dev);
                          }
                          else {
                                  ret = -EINVAL;
                          }
                          break;
                  default:
                          ret = -EOPNOTSUPP;
                  }
                  dev_put(slave_dev);
          }
  
          if (ret < 0) {
                  /* The ioctl failed, so there's no point in changing the
                   * orig_app_abi_ver. We'll restore it's value just in case
                   * we've changed it earlier in this function.
                   */
                  orig_app_abi_ver = prev_abi_ver;
          }
  
          return ret;
  }
  
  #ifdef CONFIG_NET_FASTROUTE
  static int bond_accept_fastpath(struct net_device *dev, struct dst_entry *dst)
  {
          return -1;
  }
  #endif
  
  /* 
   * in broadcast mode, we send everything to all usable interfaces.
   */
  static int bond_xmit_broadcast(struct sk_buff *skb, struct net_device *dev)
  {
          slave_t *slave, *start_at;
          struct bonding *bond = (struct bonding *) dev->priv;
          struct net_device *device_we_should_send_to = 0;
  
          if (!IS_UP(dev)) { /* bond down */
                  dev_kfree_skb(skb);
                  return 0;
          }
  
          read_lock(&bond->lock);
  
          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 */
                  read_unlock(&bond->lock);
                  dev_kfree_skb(skb);
                  return 0;
          }
  
          do {
                  if (IS_UP(slave->dev)
                      && (slave->link == BOND_LINK_UP)
                      && (slave->state == BOND_STATE_ACTIVE)) {
                          if (device_we_should_send_to) {
                                  struct sk_buff *skb2;
                                  if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
                                          printk(KERN_ERR "bond_xmit_broadcast: skb_clone() failed\n");
                                          continue;
                                  }
  
                                  skb2->dev = device_we_should_send_to;
                                  skb2->priority = 1;
                                  dev_queue_xmit(skb2);
                          }
                          device_we_should_send_to = slave->dev;
                  }
          } while ((slave = slave->next) != start_at);
  
          if (device_we_should_send_to) {
                  skb->dev = device_we_should_send_to;
                  skb->priority = 1;
                  dev_queue_xmit(skb);
          } else
                  dev_kfree_skb(skb);
  
          /* frame sent to all suitable interfaces */
          read_unlock(&bond->lock);
          return 0;
  }
  
  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;
  
          if (!IS_UP(dev)) { /* bond down */
                  dev_kfree_skb(skb);
                  return 0;
          }
  
          read_lock(&bond->lock);
  
          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(&bond->lock);
                  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_assign_current_slave(bond, slave->next);
                          write_unlock(&bond->ptrlock);
  
                          read_unlock(&bond->lock);
                          return 0;
                  }
          } while ((slave = slave->next) != start_at);
  
          /* no suitable interface, frame not sent */
          dev_kfree_skb(skb);
          read_unlock(&bond->lock);
          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;
          struct ethhdr *data = (struct ethhdr *)skb->data;
          int slave_no;
  
          if (!IS_UP(dev)) { /* bond down */
                  dev_kfree_skb(skb);
                  return 0;
          }
  
          read_lock(&bond->lock);
          slave = bond->prev;
  
          /* we're at the root, get the first slave */
          if (bond->slave_cnt == 0) {
                  /* no suitable interface, frame not sent */
                  dev_kfree_skb(skb);
                  read_unlock(&bond->lock);
                  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(&bond->lock);
                          return 0;
                  }
          } while ((slave = slave->next) != start_at);
  
          /* no suitable interface, frame not sent */
          dev_kfree_skb(skb);
          read_unlock(&bond->lock);
          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;
          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.
           * don't do this if in active backup mode because the slaves must 
           * receive packets to stay up, and the only ones they receive are 
           * broadcasts. 
           */
          if ( (bond_mode != BOND_MODE_ACTIVEBACKUP) && 
               (arp_ip_count == 1) &&
               (arp_interval > 0) && (arp_target_hw_addr == NULL) &&
               (skb->protocol == __constant_htons(ETH_P_IP) ) ) {
                  struct ethhdr *eth_hdr = 
                          (struct ethhdr *) (((char *)skb->data));
                  struct iphdr *ip_hdr = (struct iphdr *)(eth_hdr + 1);
  
                  if (arp_target[0] == ip_hdr->daddr) {
                          arp_target_hw_addr = kmalloc(ETH_ALEN, GFP_KERNEL);
                          if (arp_target_hw_addr != NULL)
                                  memcpy(arp_target_hw_addr, eth_hdr->h_dest, ETH_ALEN);
                  }
          }
  
          read_lock(&bond->lock);
  
          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(&bond->lock);
                  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(&bond->lock);
          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;
  
          memset(bond->stats, 0, sizeof(struct net_device_stats));
  
          read_lock_bh(&bond->lock);
  
          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_bh(&bond->lock);
          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;
  
          len += sprintf(buf + len, "%s\n", version);
  
          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: %s\n",
                                 bond_mode_name());
  
                  if ((bond_mode == BOND_MODE_ACTIVEBACKUP) ||
                      (bond_mode == BOND_MODE_TLB) ||
                      (bond_mode == BOND_MODE_ALB)) {
                          read_lock_bh(&bond->lock);
                          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_bh(&bond->lock);
                  }
  
                  len += sprintf(buf + len, "MII Status: ");
                  len += sprintf(buf + len, 
                                  link == BMSR_LSTATUS ? "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 * miimon);
                  len += sprintf(buf + len, "Down Delay (ms): %d\n", 
                                  downdelay * miimon);
                  len += sprintf(buf + len, "Multicast Mode: %s\n",
                                 multicast_mode_name());
  
                  read_lock_bh(&bond->lock);
  
                  if (bond_mode == BOND_MODE_8023AD) {
                          struct ad_info ad_info;
  
                          len += sprintf(buf + len, "\n802.3ad info\n");
  
                          if (bond_3ad_get_active_agg_info(bond, &ad_info)) {
                                  len += sprintf(buf + len, "bond %s has no active aggregator\n", bond->device->name);
                          } else {
                                  len += sprintf(buf + len, "Active Aggregator Info:\n");
  
                                  len += sprintf(buf + len, "\tAggregator ID: %d\n", ad_info.aggregator_id);
                                  len += sprintf(buf + len, "\tNumber of ports: %d\n", ad_info.ports);
                                  len += sprintf(buf + len, "\tActor Key: %d\n", ad_info.actor_key);
                                  len += sprintf(buf + len, "\tPartner Key: %d\n", ad_info.partner_key);
                                  len += sprintf(buf + len, "\tPartner Mac Address: %02x:%02x:%02x:%02x:%02x:%02x\n",
                                                 ad_info.partner_system[0],
                                                 ad_info.partner_system[1],
                                                 ad_info.partner_system[2],
                                                 ad_info.partner_system[3],
                                                 ad_info.partner_system[4],
                                                 ad_info.partner_system[5]);
                          }
                  }
  
                  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);
  
                          if (app_abi_ver >= 1) {
                                  len += sprintf(buf + len,
                                                 "Permanent HW addr: %02x:%02x:%02x:%02x:%02x:%02x\n",
                                                 slave->perm_hwaddr[0],
                                                 slave->perm_hwaddr[1],
                                                 slave->perm_hwaddr[2],
                                                 slave->perm_hwaddr[3],
                                                 slave->perm_hwaddr[4],
                                                 slave->perm_hwaddr[5]);
                          }
  
                          if (bond_mode == BOND_MODE_8023AD) {
                                  struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
  
                                  if (agg) {
                                          len += sprintf(buf + len, "Aggregator ID: %d\n",
                                                         agg->aggregator_identifier);
                                  } else {
                                          len += sprintf(buf + len, "Aggregator ID: N/A\n");
                                  }
                          }
                  }
                  read_unlock_bh(&bond->lock);
  
                  /*
                   * 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;
          int count;
  
  #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->current_arp_slave = NULL;
          bond->device = dev;
          dev->priv = bond;
  
          /* Initialize the device structure. */
          switch (bond_mode) {
          case BOND_MODE_ACTIVEBACKUP:
                  dev->hard_start_xmit = bond_xmit_activebackup;
                  break;
          case BOND_MODE_ROUNDROBIN:
                  dev->hard_start_xmit = bond_xmit_roundrobin;
                  break;
          case BOND_MODE_XOR:
                  dev->hard_start_xmit = bond_xmit_xor;
                  break;
          case BOND_MODE_BROADCAST:
                  dev->hard_start_xmit = bond_xmit_broadcast;
                  break;
          case BOND_MODE_8023AD:
                  dev->hard_start_xmit = bond_3ad_xmit_xor;
                  break;
          case BOND_MODE_TLB:
          case BOND_MODE_ALB:
                  dev->hard_start_xmit = bond_alb_xmit;
                  break;
          default:
                  printk(KERN_ERR "Unknown bonding mode %d\n", bond_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->set_mac_address = bond_set_mac_address;
          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", bond_mode_name());
  
          printk(KERN_INFO "%s registered with", dev->name);
          if (arp_interval > 0) {
                  printk(" ARP monitoring set to %d ms with %d target(s):", 
                          arp_interval, arp_ip_count);
                  for (count=0 ; count<arp_ip_count ; count++)
                          printk (" %s", arp_ip_target[count]);
                  printk("\n");
          } else {
                  printk("out ARP monitoring\n");
          }
  
  #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;
  }
   */
  
  /*
   * Convert string input module parms.  Accept either the
   * number of the mode or its string name.
   */
  static inline int
  bond_parse_parm(char *mode_arg, struct bond_parm_tbl *tbl)
  {
          int i;
  
          for (i = 0; tbl[i].modename != NULL; i++) {
                  if ((isdigit(*mode_arg) &&
                      tbl[i].mode == simple_strtol(mode_arg, NULL, 0)) ||
                      (0 == strncmp(mode_arg, tbl[i].modename,
                                    strlen(tbl[i].modename)))) {
                          return tbl[i].mode;
                  }
          }
  
          return -1;
  }
  
  
  static int __init bonding_init(void)
  {
          int no;
          int err;
  
          /* Find a name for this unit */
          static struct net_device *dev_bond = NULL;
  
          printk(KERN_INFO "%s", version);
  
          /*
           * Convert string parameters.
           */
          if (mode) {
                  bond_mode = bond_parse_parm(mode, bond_mode_tbl);
                  if (bond_mode == -1) {
                          printk(KERN_WARNING
                                 "bonding_init(): Invalid bonding mode \"%s\"\n",
                                 mode == NULL ? "NULL" : mode);
                          return -EINVAL;
                  }
          }
  
          if (multicast) {
                  multicast_mode = bond_parse_parm(multicast, bond_mc_tbl);
                  if (multicast_mode == -1) {
                          printk(KERN_WARNING 
                         "bonding_init(): Invalid multicast mode \"%s\"\n",
                                 multicast == NULL ? "NULL" : multicast);
                          return -EINVAL;
                  }
          }
  
          if (lacp_rate) {
                  if (bond_mode != BOND_MODE_8023AD) {
                          printk(KERN_WARNING
                                 "lacp_rate param is irrelevant in mode %s\n",
                                 bond_mode_name());
                  } else {
                          lacp_fast = bond_parse_parm(lacp_rate, bond_lacp_tbl);
                          if (lacp_fast == -1) {
                                  printk(KERN_WARNING
                                         "bonding_init(): Invalid lacp rate "
                                         "\"%s\"\n",
                                         lacp_rate == NULL ? "NULL" : lacp_rate);
  
                                  return -EINVAL;
                          }
                  }
          }
  
          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 (miimon < 0) {
                  printk(KERN_WARNING 
                         "bonding_init(): miimon module parameter (%d), "
                         "not in range 0-%d, so it was reset to %d\n",
                         miimon, INT_MAX, BOND_LINK_MON_INTERV);
                  miimon = BOND_LINK_MON_INTERV;
          }
  
          if (updelay < 0) {
                  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;
          }
  
          /* reset values for 802.3ad */
          if (bond_mode == BOND_MODE_8023AD) {
                  if (arp_interval != 0) {
                          printk(KERN_WARNING "bonding_init(): ARP monitoring"
                                 "can't be used simultaneously with 802.3ad, "
                                 "disabling ARP monitoring\n");
                          arp_interval = 0;
                  }
  
                  if (miimon == 0) {
                          printk(KERN_ERR
                                 "bonding_init(): miimon must be specified, "
                                 "otherwise bonding will not detect link failure, "
                                 "speed and duplex which are essential "
                                 "for 802.3ad operation\n");
                          printk(KERN_ERR "Forcing miimon to 100msec\n");
                          miimon = 100;
                  }
  
                  if (multicast_mode != BOND_MULTICAST_ALL) {
                          printk(KERN_ERR
                                 "bonding_init(): Multicast mode must "
                                 "be set to ALL for 802.3ad\n");
                          printk(KERN_ERR "Forcing Multicast mode to ALL\n");
                          multicast_mode = BOND_MULTICAST_ALL;
                  }
          }
  
          /* reset values for TLB/ALB */
          if ((bond_mode == BOND_MODE_TLB) ||
              (bond_mode == BOND_MODE_ALB)) {
                  if (miimon == 0) {
                          printk(KERN_ERR
                                 "bonding_init(): miimon must be specified, "
                                 "otherwise bonding will not detect link failure "
                                 "and link speed which are essential "
                                 "for TLB/ALB load balancing\n");
                          printk(KERN_ERR "Forcing miimon to 100msec\n");
                          miimon = 100;
                  }
  
                  if (multicast_mode != BOND_MULTICAST_ACTIVE) {
                          printk(KERN_ERR
                                 "bonding_init(): Multicast mode must "
                                 "be set to ACTIVE for TLB/ALB\n");
                          printk(KERN_ERR "Forcing Multicast mode to ACTIVE\n");
                          multicast_mode = BOND_MULTICAST_ACTIVE;
                  }
          }
  
          if (bond_mode == BOND_MODE_ALB) {
                  printk(KERN_INFO
                         "In ALB mode you might experience client disconnections"
                         " upon reconnection of a link if the bonding module"
                         " updelay parameter (%d msec) is incompatible with the"
                         " forwarding delay time of the switch\n", updelay);
          }
  
          if (miimon == 0) {
                  if ((updelay != 0) || (downdelay != 0)) {
                          /* just warn the user the up/down delay will have
                           * no effect since miimon is zero...
                           */
                          printk(KERN_WARNING 
                                 "bonding_init(): miimon module parameter not "
                                 "set and updelay (%d) or downdelay (%d) module "
                                 "parameter is set; updelay and downdelay have "
                                 "no effect unless miimon is set\n",
                                 updelay, downdelay);
                  }
          } else {
                  /* don't allow arp monitoring */
                  if (arp_interval != 0) {
                          printk(KERN_WARNING 
                                 "bonding_init(): miimon (%d) and arp_interval "
                                 "(%d) can't be used simultaneously, "
                                 "disabling ARP monitoring\n",
                                 miimon, arp_interval);
                          arp_interval = 0;
                  }
  
                  if ((updelay % miimon) != 0) {
                          /* updelay will be rounded in bond_init() when it
                           * is divided by miimon, we just inform user here
                           */
                          printk(KERN_WARNING 
                                 "bonding_init(): updelay (%d) is not a multiple "
                                 "of miimon (%d), updelay rounded to %d ms\n",
                                 updelay, miimon, (updelay / miimon) * miimon);
                  }
  
                  if ((downdelay % miimon) != 0) {
                          /* downdelay will be rounded in bond_init() when it
                           * is divided by miimon, we just inform user here
                           */
                          printk(KERN_WARNING 
                                 "bonding_init(): downdelay (%d) is not a "
                                 "multiple of miimon (%d), downdelay rounded "
                                 "to %d ms\n",
                                 downdelay, miimon, 
                                 (downdelay / miimon) * miimon);
                  }
          }
  
          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;
          }
  
          for (arp_ip_count=0 ;
               (arp_ip_count < MAX_ARP_IP_TARGETS) && arp_ip_target[arp_ip_count];
                arp_ip_count++ ) {
                  /* not complete check, but should be good enough to
                     catch mistakes */
                  if (!isdigit(arp_ip_target[arp_ip_count][0])) { 
                          printk(KERN_WARNING
                                 "bonding_init(): bad arp_ip_target module "
                                 "parameter (%s), ARP monitoring will not be "
                                 "performed\n",
                                 arp_ip_target[arp_ip_count]);
                          arp_interval = 0;
                  } else { 
                          u32 ip = in_aton(arp_ip_target[arp_ip_count]); 
                          arp_target[arp_ip_count] = ip;
                  }
          }
  
  
          if ( (arp_interval > 0) && (arp_ip_count==0)) {
                  /* don't allow arping if no arp_ip_target given... */
                  printk(KERN_WARNING 
                         "bonding_init(): arp_interval module parameter "
                         "(%d) specified without providing an arp_ip_target "
                         "parameter, arp_interval was reset to 0\n",
                         arp_interval);
                  arp_interval = 0;
          }
  
          if ((miimon == 0) && (arp_interval == 0)) {
                  /* miimon and arp_interval not set, we need one so things
                   * work as expected, see bonding.txt for details
                   */
                  printk(KERN_ERR 
                         "bonding_init(): either miimon or "
                         "arp_interval and arp_ip_target module parameters "
                         "must be specified, otherwise bonding will not detect "
                         "link failures! see bonding.txt for details.\n");
          }
  
          if ((primary != NULL) && (bond_mode != BOND_MODE_ACTIVEBACKUP) &&
              (bond_mode != BOND_MODE_TLB) &&
              (bond_mode != BOND_MODE_ALB)){
                  /* currently, using a primary only makes sense
                   * in active backup, TLB or ALB modes
                   */
                  printk(KERN_WARNING 
                         "bonding_init(): %s primary device specified but has "
                         "no effect in %s mode\n",
                         primary, bond_mode_name());
                  primary = NULL;
          }
  
  
          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");
  MODULE_DESCRIPTION(DRV_DESCRIPTION ", v" DRV_VERSION);
  
  /*
   * Local variables:
   *  c-indent-level: 8
   *  c-basic-offset: 8
   *  tab-width: 8
   * End:
   */