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.
     *
     */
    
    #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
    
    #include <linux/kernel.h>
    #include <linux/module.h>
    #include <linux/types.h>
    #include <linux/fcntl.h>
    #include <linux/interrupt.h>
    #include <linux/ptrace.h>
    #include <linux/ioport.h>
    #include <linux/in.h>
    #include <net/ip.h>
    #include <linux/ip.h>
    #include <linux/tcp.h>
    #include <linux/udp.h>
    #include <linux/slab.h>
    #include <linux/string.h>
    #include <linux/init.h>
    #include <linux/timer.h>
    #include <linux/socket.h>
    #include <linux/ctype.h>
    #include <linux/inet.h>
    #include <linux/bitops.h>
    #include <linux/io.h>
    #include <asm/dma.h>
    #include <linux/uaccess.h>
    #include <linux/errno.h>
    #include <linux/netdevice.h>
    #include <linux/inetdevice.h>
    #include <linux/igmp.h>
    #include <linux/etherdevice.h>
    #include <linux/skbuff.h>
    #include <net/sock.h>
    #include <linux/rtnetlink.h>
    #include <linux/smp.h>
    #include <linux/if_ether.h>
    #include <net/arp.h>
    #include <linux/mii.h>
    #include <linux/ethtool.h>
    #include <linux/if_vlan.h>
    #include <linux/if_bonding.h>
    #include <linux/jiffies.h>
    #include <linux/preempt.h>
    #include <net/route.h>
    #include <net/net_namespace.h>
    #include <net/netns/generic.h>
    #include <net/pkt_sched.h>
    #include "bonding.h"
    #include "bond_3ad.h"
    #include "bond_alb.h"
    
    /*---------------------------- Module parameters ----------------------------*/
    
    /* monitor all links that often (in milliseconds). <=0 disables monitoring */
    #define BOND_LINK_MON_INTERV    0
    #define BOND_LINK_ARP_INTERV    0
    
    static int max_bonds    = BOND_DEFAULT_MAX_BONDS;
    static int tx_queues    = BOND_DEFAULT_TX_QUEUES;
    static int num_peer_notif = 1;
    static int miimon       = BOND_LINK_MON_INTERV;
    static int updelay;
    static int downdelay;
    static int use_carrier  = 1;
    static char *mode;
    static char *primary;
    static char *primary_reselect;
   static char *lacp_rate;
   static int min_links;
   static char *ad_select;
   static char *xmit_hash_policy;
   static int arp_interval = BOND_LINK_ARP_INTERV;
   static char *arp_ip_target[BOND_MAX_ARP_TARGETS];
   static char *arp_validate;
   static char *fail_over_mac;
   static int all_slaves_active = 0;
   static struct bond_params bonding_defaults;
   static int resend_igmp = BOND_DEFAULT_RESEND_IGMP;
   
   module_param(max_bonds, int, 0);
   MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
   module_param(tx_queues, int, 0);
   MODULE_PARM_DESC(tx_queues, "Max number of transmit queues (default = 16)");
   module_param_named(num_grat_arp, num_peer_notif, int, 0644);
   MODULE_PARM_DESC(num_grat_arp, "Number of peer notifications to send on "
                                  "failover event (alias of num_unsol_na)");
   module_param_named(num_unsol_na, num_peer_notif, int, 0644);
   MODULE_PARM_DESC(num_unsol_na, "Number of peer notifications to send on "
                                  "failover event (alias of num_grat_arp)");
   module_param(miimon, int, 0);
   MODULE_PARM_DESC(miimon, "Link check interval in milliseconds");
   module_param(updelay, int, 0);
   MODULE_PARM_DESC(updelay, "Delay before considering link up, in milliseconds");
   module_param(downdelay, int, 0);
   MODULE_PARM_DESC(downdelay, "Delay before considering link down, "
                               "in milliseconds");
   module_param(use_carrier, int, 0);
   MODULE_PARM_DESC(use_carrier, "Use netif_carrier_ok (vs MII ioctls) in miimon; "
                                 "0 for off, 1 for on (default)");
   module_param(mode, charp, 0);
   MODULE_PARM_DESC(mode, "Mode of operation; 0 for balance-rr, "
                          "1 for active-backup, 2 for balance-xor, "
                          "3 for broadcast, 4 for 802.3ad, 5 for balance-tlb, "
                          "6 for balance-alb");
   module_param(primary, charp, 0);
   MODULE_PARM_DESC(primary, "Primary network device to use");
   module_param(primary_reselect, charp, 0);
   MODULE_PARM_DESC(primary_reselect, "Reselect primary slave "
                                      "once it comes up; "
                                      "0 for always (default), "
                                      "1 for only if speed of primary is "
                                      "better, "
                                      "2 for only on active slave "
                                      "failure");
   module_param(lacp_rate, charp, 0);
   MODULE_PARM_DESC(lacp_rate, "LACPDU tx rate to request from 802.3ad partner; "
                               "0 for slow, 1 for fast");
   module_param(ad_select, charp, 0);
   MODULE_PARM_DESC(ad_select, "803.ad aggregation selection logic; "
                               "0 for stable (default), 1 for bandwidth, "
                               "2 for count");
   module_param(min_links, int, 0);
   MODULE_PARM_DESC(min_links, "Minimum number of available links before turning on carrier");
   
   module_param(xmit_hash_policy, charp, 0);
   MODULE_PARM_DESC(xmit_hash_policy, "balance-xor and 802.3ad hashing method; "
                                      "0 for layer 2 (default), 1 for layer 3+4, "
                                      "2 for layer 2+3");
   module_param(arp_interval, int, 0);
   MODULE_PARM_DESC(arp_interval, "arp interval in milliseconds");
   module_param_array(arp_ip_target, charp, NULL, 0);
   MODULE_PARM_DESC(arp_ip_target, "arp targets in n.n.n.n form");
   module_param(arp_validate, charp, 0);
   MODULE_PARM_DESC(arp_validate, "validate src/dst of ARP probes; "
                                  "0 for none (default), 1 for active, "
                                  "2 for backup, 3 for all");
   module_param(fail_over_mac, charp, 0);
   MODULE_PARM_DESC(fail_over_mac, "For active-backup, do not set all slaves to "
                                   "the same MAC; 0 for none (default), "
                                   "1 for active, 2 for follow");
   module_param(all_slaves_active, int, 0);
   MODULE_PARM_DESC(all_slaves_active, "Keep all frames received on an interface"
                                        "by setting active flag for all slaves; "
                                        "0 for never (default), 1 for always.");
   module_param(resend_igmp, int, 0);
   MODULE_PARM_DESC(resend_igmp, "Number of IGMP membership reports to send on "
                                 "link failure");
   
   /*----------------------------- Global variables ----------------------------*/
   
   #ifdef CONFIG_NET_POLL_CONTROLLER
   atomic_t netpoll_block_tx = ATOMIC_INIT(0);
   #endif
   
   int bond_net_id __read_mostly;
   
   static __be32 arp_target[BOND_MAX_ARP_TARGETS];
   static int arp_ip_count;
   static int bond_mode    = BOND_MODE_ROUNDROBIN;
   static int xmit_hashtype = BOND_XMIT_POLICY_LAYER2;
   static int lacp_fast;
   
   const struct bond_parm_tbl bond_lacp_tbl[] = {
   {       "slow",         AD_LACP_SLOW},
   {       "fast",         AD_LACP_FAST},
   {       NULL,           -1},
   };
   
   const struct bond_parm_tbl bond_mode_tbl[] = {
   {       "balance-rr",           BOND_MODE_ROUNDROBIN},
   {       "active-backup",        BOND_MODE_ACTIVEBACKUP},
   {       "balance-xor",          BOND_MODE_XOR},
   {       "broadcast",            BOND_MODE_BROADCAST},
   {       "802.3ad",              BOND_MODE_8023AD},
   {       "balance-tlb",          BOND_MODE_TLB},
   {       "balance-alb",          BOND_MODE_ALB},
   {       NULL,                   -1},
   };
   
   const struct bond_parm_tbl xmit_hashtype_tbl[] = {
   {       "layer2",               BOND_XMIT_POLICY_LAYER2},
   {       "layer3+4",             BOND_XMIT_POLICY_LAYER34},
   {       "layer2+3",             BOND_XMIT_POLICY_LAYER23},
   {       NULL,                   -1},
   };
   
   const struct bond_parm_tbl arp_validate_tbl[] = {
   {       "none",                 BOND_ARP_VALIDATE_NONE},
   {       "active",               BOND_ARP_VALIDATE_ACTIVE},
   {       "backup",               BOND_ARP_VALIDATE_BACKUP},
   {       "all",                  BOND_ARP_VALIDATE_ALL},
   {       NULL,                   -1},
   };
   
   const struct bond_parm_tbl fail_over_mac_tbl[] = {
   {       "none",                 BOND_FOM_NONE},
   {       "active",               BOND_FOM_ACTIVE},
   {       "follow",               BOND_FOM_FOLLOW},
   {       NULL,                   -1},
   };
   
   const struct bond_parm_tbl pri_reselect_tbl[] = {
   {       "always",               BOND_PRI_RESELECT_ALWAYS},
   {       "better",               BOND_PRI_RESELECT_BETTER},
   {       "failure",              BOND_PRI_RESELECT_FAILURE},
   {       NULL,                   -1},
   };
   
   struct bond_parm_tbl ad_select_tbl[] = {
   {       "stable",       BOND_AD_STABLE},
   {       "bandwidth",    BOND_AD_BANDWIDTH},
   {       "count",        BOND_AD_COUNT},
   {       NULL,           -1},
   };
   
   /*-------------------------- Forward declarations ---------------------------*/
   
   static int bond_init(struct net_device *bond_dev);
   static void bond_uninit(struct net_device *bond_dev);
   
   /*---------------------------- General routines -----------------------------*/
   
   const char *bond_mode_name(int mode)
   {
           static const char *names[] = {
                   [BOND_MODE_ROUNDROBIN] = "load balancing (round-robin)",
                   [BOND_MODE_ACTIVEBACKUP] = "fault-tolerance (active-backup)",
                   [BOND_MODE_XOR] = "load balancing (xor)",
                   [BOND_MODE_BROADCAST] = "fault-tolerance (broadcast)",
                   [BOND_MODE_8023AD] = "IEEE 802.3ad Dynamic link aggregation",
                   [BOND_MODE_TLB] = "transmit load balancing",
                   [BOND_MODE_ALB] = "adaptive load balancing",
           };
   
           if (mode < 0 || mode > BOND_MODE_ALB)
                   return "unknown";
   
           return names[mode];
   }
   
   /*---------------------------------- VLAN -----------------------------------*/
   
   /**
    * bond_add_vlan - add a new vlan id on bond
    * @bond: bond that got the notification
    * @vlan_id: the vlan id to add
    *
    * Returns -ENOMEM if allocation failed.
    */
   static int bond_add_vlan(struct bonding *bond, unsigned short vlan_id)
   {
           struct vlan_entry *vlan;
   
           pr_debug("bond: %s, vlan id %d\n",
                    (bond ? bond->dev->name : "None"), vlan_id);
   
           vlan = kzalloc(sizeof(struct vlan_entry), GFP_KERNEL);
           if (!vlan)
                   return -ENOMEM;
   
           INIT_LIST_HEAD(&vlan->vlan_list);
           vlan->vlan_id = vlan_id;
   
           write_lock_bh(&bond->lock);
   
           list_add_tail(&vlan->vlan_list, &bond->vlan_list);
   
           write_unlock_bh(&bond->lock);
   
           pr_debug("added VLAN ID %d on bond %s\n", vlan_id, bond->dev->name);
   
           return 0;
   }
   
   /**
    * bond_del_vlan - delete a vlan id from bond
    * @bond: bond that got the notification
    * @vlan_id: the vlan id to delete
    *
    * returns -ENODEV if @vlan_id was not found in @bond.
    */
   static int bond_del_vlan(struct bonding *bond, unsigned short vlan_id)
   {
           struct vlan_entry *vlan;
           int res = -ENODEV;
   
           pr_debug("bond: %s, vlan id %d\n", bond->dev->name, vlan_id);
   
           block_netpoll_tx();
           write_lock_bh(&bond->lock);
   
           list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                   if (vlan->vlan_id == vlan_id) {
                           list_del(&vlan->vlan_list);
   
                           if (bond_is_lb(bond))
                                   bond_alb_clear_vlan(bond, vlan_id);
   
                           pr_debug("removed VLAN ID %d from bond %s\n",
                                    vlan_id, bond->dev->name);
   
                           kfree(vlan);
   
                           res = 0;
                           goto out;
                   }
           }
   
           pr_debug("couldn't find VLAN ID %d in bond %s\n",
                    vlan_id, bond->dev->name);
   
   out:
           write_unlock_bh(&bond->lock);
           unblock_netpoll_tx();
           return res;
   }
   
   /**
    * bond_next_vlan - safely skip to the next item in the vlans list.
    * @bond: the bond we're working on
    * @curr: item we're advancing from
    *
    * Returns %NULL if list is empty, bond->next_vlan if @curr is %NULL,
    * or @curr->next otherwise (even if it is @curr itself again).
    *
    * Caller must hold bond->lock
    */
   struct vlan_entry *bond_next_vlan(struct bonding *bond, struct vlan_entry *curr)
   {
           struct vlan_entry *next, *last;
   
           if (list_empty(&bond->vlan_list))
                   return NULL;
   
           if (!curr) {
                   next = list_entry(bond->vlan_list.next,
                                     struct vlan_entry, vlan_list);
           } else {
                   last = list_entry(bond->vlan_list.prev,
                                     struct vlan_entry, vlan_list);
                   if (last == curr) {
                           next = list_entry(bond->vlan_list.next,
                                             struct vlan_entry, vlan_list);
                   } else {
                           next = list_entry(curr->vlan_list.next,
                                             struct vlan_entry, vlan_list);
                   }
           }
   
           return next;
   }
   
   /**
    * bond_dev_queue_xmit - Prepare skb for xmit.
    *
    * @bond: bond device that got this skb for tx.
    * @skb: hw accel VLAN tagged skb to transmit
    * @slave_dev: slave that is supposed to xmit this skbuff
    */
   int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb,
                           struct net_device *slave_dev)
   {
           skb->dev = slave_dev;
   
           BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
                        sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
           skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
   
           if (unlikely(netpoll_tx_running(bond->dev)))
                   bond_netpoll_send_skb(bond_get_slave_by_dev(bond, slave_dev), skb);
           else
                   dev_queue_xmit(skb);
   
           return 0;
   }
   
   /*
    * In the following 2 functions, bond_vlan_rx_add_vid and bond_vlan_rx_kill_vid,
    * We don't protect the slave list iteration with a lock because:
    * a. This operation is performed in IOCTL context,
    * b. The operation is protected by the RTNL semaphore in the 8021q code,
    * c. Holding a lock with BH disabled while directly calling a base driver
    *    entry point is generally a BAD idea.
    *
    * The design of synchronization/protection for this operation in the 8021q
    * module is good for one or more VLAN devices over a single physical device
    * and cannot be extended for a teaming solution like bonding, so there is a
    * potential race condition here where a net device from the vlan group might
    * be referenced (either by a base driver or the 8021q code) while it is being
    * removed from the system. However, it turns out we're not making matters
    * worse, and if it works for regular VLAN usage it will work here too.
   */
   
   /**
    * bond_vlan_rx_add_vid - Propagates adding an id to slaves
    * @bond_dev: bonding net device that got called
    * @vid: vlan id being added
    */
   static int bond_vlan_rx_add_vid(struct net_device *bond_dev, uint16_t vid)
   {
           struct bonding *bond = netdev_priv(bond_dev);
           struct slave *slave, *stop_at;
           int i, res;
   
           bond_for_each_slave(bond, slave, i) {
                   res = vlan_vid_add(slave->dev, vid);
                   if (res)
                           goto unwind;
           }
   
           res = bond_add_vlan(bond, vid);
           if (res) {
                   pr_err("%s: Error: Failed to add vlan id %d\n",
                          bond_dev->name, vid);
                   return res;
           }
   
           return 0;
   
   unwind:
           /* unwind from head to the slave that failed */
           stop_at = slave;
           bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at)
                   vlan_vid_del(slave->dev, vid);
   
           return res;
   }
   
   /**
    * bond_vlan_rx_kill_vid - Propagates deleting an id to slaves
    * @bond_dev: bonding net device that got called
    * @vid: vlan id being removed
    */
   static int bond_vlan_rx_kill_vid(struct net_device *bond_dev, uint16_t vid)
   {
           struct bonding *bond = netdev_priv(bond_dev);
           struct slave *slave;
           int i, res;
   
           bond_for_each_slave(bond, slave, i)
                   vlan_vid_del(slave->dev, vid);
   
           res = bond_del_vlan(bond, vid);
           if (res) {
                   pr_err("%s: Error: Failed to remove vlan id %d\n",
                          bond_dev->name, vid);
                   return res;
           }
   
           return 0;
   }
   
   static void bond_add_vlans_on_slave(struct bonding *bond, struct net_device *slave_dev)
   {
           struct vlan_entry *vlan;
           int res;
   
           list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                   res = vlan_vid_add(slave_dev, vlan->vlan_id);
                   if (res)
                           pr_warning("%s: Failed to add vlan id %d to device %s\n",
                                      bond->dev->name, vlan->vlan_id,
                                      slave_dev->name);
           }
   }
   
   static void bond_del_vlans_from_slave(struct bonding *bond,
                                         struct net_device *slave_dev)
   {
           struct vlan_entry *vlan;
   
           list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                   if (!vlan->vlan_id)
                           continue;
                   vlan_vid_del(slave_dev, vlan->vlan_id);
           }
   }
   
   /*------------------------------- Link status -------------------------------*/
   
   /*
    * Set the carrier state for the master according to the state of its
    * slaves.  If any slaves are up, the master is up.  In 802.3ad mode,
    * do special 802.3ad magic.
    *
    * Returns zero if carrier state does not change, nonzero if it does.
    */
   static int bond_set_carrier(struct bonding *bond)
   {
           struct slave *slave;
           int i;
   
           if (bond->slave_cnt == 0)
                   goto down;
   
           if (bond->params.mode == BOND_MODE_8023AD)
                   return bond_3ad_set_carrier(bond);
   
           bond_for_each_slave(bond, slave, i) {
                   if (slave->link == BOND_LINK_UP) {
                           if (!netif_carrier_ok(bond->dev)) {
                                   netif_carrier_on(bond->dev);
                                   return 1;
                           }
                           return 0;
                   }
           }
   
   down:
           if (netif_carrier_ok(bond->dev)) {
                   netif_carrier_off(bond->dev);
                   return 1;
           }
           return 0;
   }
   
   /*
    * Get link speed and duplex from the slave's base driver
    * using ethtool. If for some reason the call fails or the
    * values are invalid, set speed and duplex to -1,
    * and return.
    */
   static void bond_update_speed_duplex(struct slave *slave)
   {
           struct net_device *slave_dev = slave->dev;
           struct ethtool_cmd ecmd;
           u32 slave_speed;
           int res;
   
           slave->speed = SPEED_UNKNOWN;
           slave->duplex = DUPLEX_UNKNOWN;
   
           res = __ethtool_get_settings(slave_dev, &ecmd);
           if (res < 0)
                   return;
   
           slave_speed = ethtool_cmd_speed(&ecmd);
           if (slave_speed == 0 || slave_speed == ((__u32) -1))
                   return;
   
           switch (ecmd.duplex) {
           case DUPLEX_FULL:
           case DUPLEX_HALF:
                   break;
           default:
                   return;
           }
   
           slave->speed = slave_speed;
           slave->duplex = ecmd.duplex;
   
           return;
   }
   
   /*
    * if <dev> supports MII link status reporting, check its link status.
    *
    * We either do MII/ETHTOOL ioctls, or check netif_carrier_ok(),
    * depending upon the setting of the use_carrier parameter.
    *
    * Return either BMSR_LSTATUS, meaning that the link is up (or we
    * can't tell and just pretend it is), or 0, meaning that the link is
    * down.
    *
    * If reporting is non-zero, instead of faking link up, return -1 if
    * both ETHTOOL and MII ioctls fail (meaning the device does not
    * support them).  If use_carrier is set, return whatever it says.
    * It'd be nice if there was a good way to tell if a driver supports
    * netif_carrier, but there really isn't.
    */
   static int bond_check_dev_link(struct bonding *bond,
                                  struct net_device *slave_dev, int reporting)
   {
           const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
           int (*ioctl)(struct net_device *, struct ifreq *, int);
           struct ifreq ifr;
           struct mii_ioctl_data *mii;
   
           if (!reporting && !netif_running(slave_dev))
                   return 0;
   
           if (bond->params.use_carrier)
                   return netif_carrier_ok(slave_dev) ? BMSR_LSTATUS : 0;
   
           /* Try to get link status using Ethtool first. */
           if (slave_dev->ethtool_ops->get_link)
                   return slave_dev->ethtool_ops->get_link(slave_dev) ?
                           BMSR_LSTATUS : 0;
   
           /* Ethtool can't be used, fallback to MII ioctls. */
           ioctl = slave_ops->ndo_do_ioctl;
           if (ioctl) {
                   /* TODO: set pointer to correct ioctl on a per team member */
                   /*       bases to make this more efficient. that is, once  */
                   /*       we determine the correct ioctl, we will always    */
                   /*       call it and not the others for that team          */
                   /*       member.                                           */
   
                   /*
                    * We cannot assume that SIOCGMIIPHY will also read a
                    * register; not all network drivers (e.g., e100)
                    * support that.
                    */
   
                   /* Yes, the mii is overlaid on the ifreq.ifr_ifru */
                   strncpy(ifr.ifr_name, slave_dev->name, IFNAMSIZ);
                   mii = if_mii(&ifr);
                   if (IOCTL(slave_dev, &ifr, SIOCGMIIPHY) == 0) {
                           mii->reg_num = MII_BMSR;
                           if (IOCTL(slave_dev, &ifr, SIOCGMIIREG) == 0)
                                   return mii->val_out & BMSR_LSTATUS;
                   }
           }
   
           /*
            * If reporting, report that either there's no dev->do_ioctl,
            * or both SIOCGMIIREG and get_link failed (meaning that we
            * cannot report link status).  If not reporting, pretend
            * we're ok.
            */
           return reporting ? -1 : BMSR_LSTATUS;
   }
   
   /*----------------------------- Multicast list ------------------------------*/
   
   /*
    * Push the promiscuity flag down to appropriate slaves
    */
   static int bond_set_promiscuity(struct bonding *bond, int inc)
   {
           int err = 0;
           if (USES_PRIMARY(bond->params.mode)) {
                   /* write lock already acquired */
                   if (bond->curr_active_slave) {
                           err = dev_set_promiscuity(bond->curr_active_slave->dev,
                                                     inc);
                   }
           } else {
                   struct slave *slave;
                   int i;
                   bond_for_each_slave(bond, slave, i) {
                           err = dev_set_promiscuity(slave->dev, inc);
                           if (err)
                                   return err;
                   }
           }
           return err;
   }
   
   /*
    * Push the allmulti flag down to all slaves
    */
   static int bond_set_allmulti(struct bonding *bond, int inc)
   {
           int err = 0;
           if (USES_PRIMARY(bond->params.mode)) {
                   /* write lock already acquired */
                   if (bond->curr_active_slave) {
                           err = dev_set_allmulti(bond->curr_active_slave->dev,
                                                  inc);
                   }
           } else {
                   struct slave *slave;
                   int i;
                   bond_for_each_slave(bond, slave, i) {
                           err = dev_set_allmulti(slave->dev, inc);
                           if (err)
                                   return err;
                   }
           }
           return err;
   }
   
   /*
    * Add a Multicast address to slaves
    * according to mode
    */
   static void bond_mc_add(struct bonding *bond, void *addr)
   {
           if (USES_PRIMARY(bond->params.mode)) {
                   /* write lock already acquired */
                   if (bond->curr_active_slave)
                           dev_mc_add(bond->curr_active_slave->dev, addr);
           } else {
                   struct slave *slave;
                   int i;
   
                   bond_for_each_slave(bond, slave, i)
                           dev_mc_add(slave->dev, addr);
           }
   }
   
   /*
    * Remove a multicast address from slave
    * according to mode
    */
   static void bond_mc_del(struct bonding *bond, void *addr)
   {
           if (USES_PRIMARY(bond->params.mode)) {
                   /* write lock already acquired */
                   if (bond->curr_active_slave)
                           dev_mc_del(bond->curr_active_slave->dev, addr);
           } else {
                   struct slave *slave;
                   int i;
                   bond_for_each_slave(bond, slave, i) {
                           dev_mc_del(slave->dev, addr);
                   }
           }
   }
   
   
   static void __bond_resend_igmp_join_requests(struct net_device *dev)
   {
           struct in_device *in_dev;
   
           rcu_read_lock();
           in_dev = __in_dev_get_rcu(dev);
           if (in_dev)
                   ip_mc_rejoin_groups(in_dev);
           rcu_read_unlock();
   }
   
   /*
    * Retrieve the list of registered multicast addresses for the bonding
    * device and retransmit an IGMP JOIN request to the current active
    * slave.
    */
   static void bond_resend_igmp_join_requests(struct bonding *bond)
   {
           struct net_device *bond_dev, *vlan_dev, *master_dev;
           struct vlan_entry *vlan;
   
           read_lock(&bond->lock);
   
           bond_dev = bond->dev;
   
           /* rejoin all groups on bond device */
           __bond_resend_igmp_join_requests(bond_dev);
   
           /*
            * if bond is enslaved to a bridge,
            * then rejoin all groups on its master
            */
           master_dev = bond_dev->master;
           if (master_dev)
                   if ((master_dev->priv_flags & IFF_EBRIDGE)
                           && (bond_dev->priv_flags & IFF_BRIDGE_PORT))
                           __bond_resend_igmp_join_requests(master_dev);
   
           /* rejoin all groups on vlan devices */
           list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                   rcu_read_lock();
                   vlan_dev = __vlan_find_dev_deep(bond_dev,
                                                   vlan->vlan_id);
                   rcu_read_unlock();
                   if (vlan_dev)
                           __bond_resend_igmp_join_requests(vlan_dev);
           }
   
           if (--bond->igmp_retrans > 0)
                   queue_delayed_work(bond->wq, &bond->mcast_work, HZ/5);
   
           read_unlock(&bond->lock);
   }
   
   static void bond_resend_igmp_join_requests_delayed(struct work_struct *work)
   {
           struct bonding *bond = container_of(work, struct bonding,
                                               mcast_work.work);
           bond_resend_igmp_join_requests(bond);
   }
   
   /*
    * flush all members of flush->mc_list from device dev->mc_list
    */
   static void bond_mc_list_flush(struct net_device *bond_dev,
                                  struct net_device *slave_dev)
   {
           struct bonding *bond = netdev_priv(bond_dev);
           struct netdev_hw_addr *ha;
   
           netdev_for_each_mc_addr(ha, bond_dev)
                   dev_mc_del(slave_dev, ha->addr);
   
           if (bond->params.mode == BOND_MODE_8023AD) {
                   /* del lacpdu mc addr from mc list */
                   u8 lacpdu_multicast[ETH_ALEN] = MULTICAST_LACPDU_ADDR;
   
                   dev_mc_del(slave_dev, lacpdu_multicast);
           }
   }
   
   /*--------------------------- Active slave change ---------------------------*/
   
   /*
    * Update the mc list and multicast-related flags for the new and
    * old active slaves (if any) according to the multicast mode, and
    * promiscuous flags unconditionally.
    */
   static void bond_mc_swap(struct bonding *bond, struct slave *new_active,
                            struct slave *old_active)
   {
           struct netdev_hw_addr *ha;
   
           if (!USES_PRIMARY(bond->params.mode))
                   /* nothing to do -  mc list is already up-to-date on
                    * all slaves
                    */
                   return;
   
           if (old_active) {
                   if (bond->dev->flags & IFF_PROMISC)
                           dev_set_promiscuity(old_active->dev, -1);
   
                   if (bond->dev->flags & IFF_ALLMULTI)
                           dev_set_allmulti(old_active->dev, -1);
   
                   netdev_for_each_mc_addr(ha, bond->dev)
                           dev_mc_del(old_active->dev, ha->addr);
           }
   
           if (new_active) {
                   /* FIXME: Signal errors upstream. */
                   if (bond->dev->flags & IFF_PROMISC)
                           dev_set_promiscuity(new_active->dev, 1);
   
                   if (bond->dev->flags & IFF_ALLMULTI)
                           dev_set_allmulti(new_active->dev, 1);
   
                   netdev_for_each_mc_addr(ha, bond->dev)
                           dev_mc_add(new_active->dev, ha->addr);
           }
   }
   
   /*
    * bond_do_fail_over_mac
    *
    * Perform special MAC address swapping for fail_over_mac settings
    *
    * Called with RTNL, bond->lock for read, curr_slave_lock for write_bh.
    */
   static void bond_do_fail_over_mac(struct bonding *bond,
                                     struct slave *new_active,
                                     struct slave *old_active)
           __releases(&bond->curr_slave_lock)
           __releases(&bond->lock)
           __acquires(&bond->lock)
           __acquires(&bond->curr_slave_lock)
   {
           u8 tmp_mac[ETH_ALEN];
           struct sockaddr saddr;
           int rv;
   
           switch (bond->params.fail_over_mac) {
           case BOND_FOM_ACTIVE:
                   if (new_active) {
                           memcpy(bond->dev->dev_addr,  new_active->dev->dev_addr,
                                  new_active->dev->addr_len);
                           write_unlock_bh(&bond->curr_slave_lock);
                           read_unlock(&bond->lock);
                           call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
                           read_lock(&bond->lock);
                           write_lock_bh(&bond->curr_slave_lock);
                   }
                   break;
           case BOND_FOM_FOLLOW:
                   /*
                    * if new_active && old_active, swap them
                    * if just old_active, do nothing (going to no active slave)
                    * if just new_active, set new_active to bond's MAC
                    */
                   if (!new_active)
                           return;
   
                   write_unlock_bh(&bond->curr_slave_lock);
                   read_unlock(&bond->lock);
   
                   if (old_active) {
                           memcpy(tmp_mac, new_active->dev->dev_addr, ETH_ALEN);
                           memcpy(saddr.sa_data, old_active->dev->dev_addr,
                                  ETH_ALEN);
                           saddr.sa_family = new_active->dev->type;
                   } else {
                           memcpy(saddr.sa_data, bond->dev->dev_addr, ETH_ALEN);
                           saddr.sa_family = bond->dev->type;
                   }
   
                   rv = dev_set_mac_address(new_active->dev, &saddr);
                   if (rv) {
                           pr_err("%s: Error %d setting MAC of slave %s\n",
                                  bond->dev->name, -rv, new_active->dev->name);
                           goto out;
                   }
   
                   if (!old_active)
                           goto out;
   
                   memcpy(saddr.sa_data, tmp_mac, ETH_ALEN);
                   saddr.sa_family = old_active->dev->type;
   
                   rv = dev_set_mac_address(old_active->dev, &saddr);
                   if (rv)
                           pr_err("%s: Error %d setting MAC of slave %s\n",
                                  bond->dev->name, -rv, new_active->dev->name);
   out:
                   read_lock(&bond->lock);
                   write_lock_bh(&bond->curr_slave_lock);
                   break;
           default:
                   pr_err("%s: bond_do_fail_over_mac impossible: bad policy %d\n",
                          bond->dev->name, bond->params.fail_over_mac);
                   break;
           }
   
   }
   
   static bool bond_should_change_active(struct bonding *bond)
   {
           struct slave *prim = bond->primary_slave;
           struct slave *curr = bond->curr_active_slave;
   
           if (!prim || !curr || curr->link != BOND_LINK_UP)
                   return true;
           if (bond->force_primary) {
                   bond->force_primary = false;
                   return true;
           }
           if (bond->params.primary_reselect == BOND_PRI_RESELECT_BETTER &&
               (prim->speed < curr->speed ||
                (prim->speed == curr->speed && prim->duplex <= curr->duplex)))
                   return false;
           if (bond->params.primary_reselect == BOND_PRI_RESELECT_FAILURE)
                   return false;
           return true;
   }
   
   /**
    * find_best_interface - select the best available slave to be the active one
    * @bond: our bonding struct
    *
    * Warning: Caller must hold curr_slave_lock for writing.
    */
   static struct slave *bond_find_best_slave(struct bonding *bond)
   {
           struct slave *new_active, *old_active;
           struct slave *bestslave = NULL;
           int mintime = bond->params.updelay;
           int i;
   
           new_active = bond->curr_active_slave;
   
           if (!new_active) { /* there were no active slaves left */
                   if (bond->slave_cnt > 0)   /* found one slave */
                           new_active = bond->first_slave;
                   else
                           return NULL; /* still no slave, return NULL */
           }
   
           if ((bond->primary_slave) &&
               bond->primary_slave->link == BOND_LINK_UP &&
               bond_should_change_active(bond)) {
                   new_active = bond->primary_slave;
           }
   
           /* remember where to stop iterating over the slaves */
           old_active = new_active;
  
          bond_for_each_slave_from(bond, new_active, i, old_active) {
                  if (new_active->link == BOND_LINK_UP) {
                          return new_active;
                  } else if (new_active->link == BOND_LINK_BACK &&
                             IS_UP(new_active->dev)) {
                          /* link up, but waiting for stabilization */
                          if (new_active->delay < mintime) {
                                  mintime = new_active->delay;
                                  bestslave = new_active;
                          }
                  }
          }
  
          return bestslave;
  }
  
  static bool bond_should_notify_peers(struct bonding *bond)
  {
          struct slave *slave = bond->curr_active_slave;
  
          pr_debug("bond_should_notify_peers: bond %s slave %s\n",
                   bond->dev->name, slave ? slave->dev->name : "NULL");
  
          if (!slave || !bond->send_peer_notif ||
              test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
                  return false;
  
          bond->send_peer_notif--;
          return true;
  }
  
  /**
   * change_active_interface - change the active slave into the specified one
   * @bond: our bonding struct
   * @new: the new slave to make the active one
   *
   * Set the new slave to the bond's settings and unset them on the old
   * curr_active_slave.
   * Setting include flags, mc-list, promiscuity, allmulti, etc.
   *
   * If @new's link state is %BOND_LINK_BACK we'll set it to %BOND_LINK_UP,
   * because it is apparently the best available slave we have, even though its
   * updelay hasn't timed out yet.
   *
   * If new_active is not NULL, caller must hold bond->lock for read and
   * curr_slave_lock for write_bh.
   */
  void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
  {
          struct slave *old_active = bond->curr_active_slave;
  
          if (old_active == new_active)
                  return;
  
          if (new_active) {
                  new_active->jiffies = jiffies;
  
                  if (new_active->link == BOND_LINK_BACK) {
                          if (USES_PRIMARY(bond->params.mode)) {
                                  pr_info("%s: making interface %s the new active one %d ms earlier.\n",
                                          bond->dev->name, new_active->dev->name,
                                          (bond->params.updelay - new_active->delay) * bond->params.miimon);
                          }
  
                          new_active->delay = 0;
                          new_active->link = BOND_LINK_UP;
  
                          if (bond->params.mode == BOND_MODE_8023AD)
                                  bond_3ad_handle_link_change(new_active, BOND_LINK_UP);
  
                          if (bond_is_lb(bond))
                                  bond_alb_handle_link_change(bond, new_active, BOND_LINK_UP);
                  } else {
                          if (USES_PRIMARY(bond->params.mode)) {
                                  pr_info("%s: making interface %s the new active one.\n",
                                          bond->dev->name, new_active->dev->name);
                          }
                  }
          }
  
          if (USES_PRIMARY(bond->params.mode))
                  bond_mc_swap(bond, new_active, old_active);
  
          if (bond_is_lb(bond)) {
                  bond_alb_handle_active_change(bond, new_active);
                  if (old_active)
                          bond_set_slave_inactive_flags(old_active);
                  if (new_active)
                          bond_set_slave_active_flags(new_active);
          } else {
                  bond->curr_active_slave = new_active;
          }
  
          if (bond->params.mode == BOND_MODE_ACTIVEBACKUP) {
                  if (old_active)
                          bond_set_slave_inactive_flags(old_active);
  
                  if (new_active) {
                          bool should_notify_peers = false;
  
                          bond_set_slave_active_flags(new_active);
  
                          if (bond->params.fail_over_mac)
                                  bond_do_fail_over_mac(bond, new_active,
                                                        old_active);
  
                          if (netif_running(bond->dev)) {
                                  bond->send_peer_notif =
                                          bond->params.num_peer_notif;
                                  should_notify_peers =
                                          bond_should_notify_peers(bond);
                          }
  
                          write_unlock_bh(&bond->curr_slave_lock);
                          read_unlock(&bond->lock);
  
                          call_netdevice_notifiers(NETDEV_BONDING_FAILOVER, bond->dev);
                          if (should_notify_peers)
                                  call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
                                                           bond->dev);
  
                          read_lock(&bond->lock);
                          write_lock_bh(&bond->curr_slave_lock);
                  }
          }
  
          /* resend IGMP joins since active slave has changed or
           * all were sent on curr_active_slave.
           * resend only if bond is brought up with the affected
           * bonding modes and the retransmission is enabled */
          if (netif_running(bond->dev) && (bond->params.resend_igmp > 0) &&
              ((USES_PRIMARY(bond->params.mode) && new_active) ||
               bond->params.mode == BOND_MODE_ROUNDROBIN)) {
                  bond->igmp_retrans = bond->params.resend_igmp;
                  queue_delayed_work(bond->wq, &bond->mcast_work, 0);
          }
  }
  
  /**
   * bond_select_active_slave - select a new active slave, if needed
   * @bond: our bonding struct
   *
   * This functions should be called when one of the following occurs:
   * - The old curr_active_slave has been released or lost its link.
   * - The primary_slave has got its link back.
   * - A slave has got its link back and there's no old curr_active_slave.
   *
   * Caller must hold bond->lock for read and curr_slave_lock for write_bh.
   */
  void bond_select_active_slave(struct bonding *bond)
  {
          struct slave *best_slave;
          int rv;
  
          best_slave = bond_find_best_slave(bond);
          if (best_slave != bond->curr_active_slave) {
                  bond_change_active_slave(bond, best_slave);
                  rv = bond_set_carrier(bond);
                  if (!rv)
                          return;
  
                  if (netif_carrier_ok(bond->dev)) {
                          pr_info("%s: first active interface up!\n",
                                  bond->dev->name);
                  } else {
                          pr_info("%s: now running without any active interface !\n",
                                  bond->dev->name);
                  }
          }
  }
  
  /*--------------------------- slave list handling ---------------------------*/
  
  /*
   * This function attaches the slave to the end of list.
   *
   * bond->lock held for writing by caller.
   */
  static void bond_attach_slave(struct bonding *bond, struct slave *new_slave)
  {
          if (bond->first_slave == NULL) { /* attaching the first slave */
                  new_slave->next = new_slave;
                  new_slave->prev = new_slave;
                  bond->first_slave = new_slave;
          } else {
                  new_slave->next = bond->first_slave;
                  new_slave->prev = bond->first_slave->prev;
                  new_slave->next->prev = new_slave;
                  new_slave->prev->next = new_slave;
          }
  
          bond->slave_cnt++;
  }
  
  /*
   * This function detaches the slave from the list.
   * WARNING: no check is made to verify if the slave effectively
   * belongs to <bond>.
   * Nothing is freed on return, structures are just unchained.
   * If any slave pointer in bond was pointing to <slave>,
   * it should be changed by the calling function.
   *
   * bond->lock held for writing by caller.
   */
  static void bond_detach_slave(struct bonding *bond, struct slave *slave)
  {
          if (slave->next)
                  slave->next->prev = slave->prev;
  
          if (slave->prev)
                  slave->prev->next = slave->next;
  
          if (bond->first_slave == slave) { /* slave is the first slave */
                  if (bond->slave_cnt > 1) { /* there are more slave */
                          bond->first_slave = slave->next;
                  } else {
                          bond->first_slave = NULL; /* slave was the last one */
                  }
          }
  
          slave->next = NULL;
          slave->prev = NULL;
          bond->slave_cnt--;
  }
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
  static inline int slave_enable_netpoll(struct slave *slave)
  {
          struct netpoll *np;
          int err = 0;
  
          np = kzalloc(sizeof(*np), GFP_ATOMIC);
          err = -ENOMEM;
          if (!np)
                  goto out;
  
          err = __netpoll_setup(np, slave->dev, GFP_ATOMIC);
          if (err) {
                  kfree(np);
                  goto out;
          }
          slave->np = np;
  out:
          return err;
  }
  static inline void slave_disable_netpoll(struct slave *slave)
  {
          struct netpoll *np = slave->np;
  
          if (!np)
                  return;
  
          slave->np = NULL;
          __netpoll_free_rcu(np);
  }
  static inline bool slave_dev_support_netpoll(struct net_device *slave_dev)
  {
          if (slave_dev->priv_flags & IFF_DISABLE_NETPOLL)
                  return false;
          if (!slave_dev->netdev_ops->ndo_poll_controller)
                  return false;
          return true;
  }
  
  static void bond_poll_controller(struct net_device *bond_dev)
  {
  }
  
  static void __bond_netpoll_cleanup(struct bonding *bond)
  {
          struct slave *slave;
          int i;
  
          bond_for_each_slave(bond, slave, i)
                  if (IS_UP(slave->dev))
                          slave_disable_netpoll(slave);
  }
  static void bond_netpoll_cleanup(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
  
          read_lock(&bond->lock);
          __bond_netpoll_cleanup(bond);
          read_unlock(&bond->lock);
  }
  
  static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, gfp_t gfp)
  {
          struct bonding *bond = netdev_priv(dev);
          struct slave *slave;
          int i, err = 0;
  
          read_lock(&bond->lock);
          bond_for_each_slave(bond, slave, i) {
                  err = slave_enable_netpoll(slave);
                  if (err) {
                          __bond_netpoll_cleanup(bond);
                          break;
                  }
          }
          read_unlock(&bond->lock);
          return err;
  }
  
  static struct netpoll_info *bond_netpoll_info(struct bonding *bond)
  {
          return bond->dev->npinfo;
  }
  
  #else
  static inline int slave_enable_netpoll(struct slave *slave)
  {
          return 0;
  }
  static inline void slave_disable_netpoll(struct slave *slave)
  {
  }
  static void bond_netpoll_cleanup(struct net_device *bond_dev)
  {
  }
  #endif
  
  /*---------------------------------- IOCTL ----------------------------------*/
  
  static int bond_sethwaddr(struct net_device *bond_dev,
                            struct net_device *slave_dev)
  {
          pr_debug("bond_dev=%p\n", bond_dev);
          pr_debug("slave_dev=%p\n", slave_dev);
          pr_debug("slave_dev->addr_len=%d\n", slave_dev->addr_len);
          memcpy(bond_dev->dev_addr, slave_dev->dev_addr, slave_dev->addr_len);
          return 0;
  }
  
  static netdev_features_t bond_fix_features(struct net_device *dev,
          netdev_features_t features)
  {
          struct slave *slave;
          struct bonding *bond = netdev_priv(dev);
          netdev_features_t mask;
          int i;
  
          read_lock(&bond->lock);
  
          if (!bond->first_slave) {
                  /* Disable adding VLANs to empty bond. But why? --mq */
                  features |= NETIF_F_VLAN_CHALLENGED;
                  goto out;
          }
  
          mask = features;
          features &= ~NETIF_F_ONE_FOR_ALL;
          features |= NETIF_F_ALL_FOR_ALL;
  
          bond_for_each_slave(bond, slave, i) {
                  features = netdev_increment_features(features,
                                                       slave->dev->features,
                                                       mask);
          }
  
  out:
          read_unlock(&bond->lock);
          return features;
  }
  
  #define BOND_VLAN_FEATURES      (NETIF_F_ALL_CSUM | NETIF_F_SG | \
                                   NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
                                   NETIF_F_HIGHDMA | NETIF_F_LRO)
  
  static void bond_compute_features(struct bonding *bond)
  {
          struct slave *slave;
          struct net_device *bond_dev = bond->dev;
          netdev_features_t vlan_features = BOND_VLAN_FEATURES;
          unsigned short max_hard_header_len = ETH_HLEN;
          unsigned int gso_max_size = GSO_MAX_SIZE;
          u16 gso_max_segs = GSO_MAX_SEGS;
          int i;
          unsigned int flags, dst_release_flag = IFF_XMIT_DST_RELEASE;
  
          read_lock(&bond->lock);
  
          if (!bond->first_slave)
                  goto done;
  
          bond_for_each_slave(bond, slave, i) {
                  vlan_features = netdev_increment_features(vlan_features,
                          slave->dev->vlan_features, BOND_VLAN_FEATURES);
  
                  dst_release_flag &= slave->dev->priv_flags;
                  if (slave->dev->hard_header_len > max_hard_header_len)
                          max_hard_header_len = slave->dev->hard_header_len;
  
                  gso_max_size = min(gso_max_size, slave->dev->gso_max_size);
                  gso_max_segs = min(gso_max_segs, slave->dev->gso_max_segs);
          }
  
  done:
          bond_dev->vlan_features = vlan_features;
          bond_dev->hard_header_len = max_hard_header_len;
          bond_dev->gso_max_segs = gso_max_segs;
          netif_set_gso_max_size(bond_dev, gso_max_size);
  
          flags = bond_dev->priv_flags & ~IFF_XMIT_DST_RELEASE;
          bond_dev->priv_flags = flags | dst_release_flag;
  
          read_unlock(&bond->lock);
  
          netdev_change_features(bond_dev);
  }
  
  static void bond_setup_by_slave(struct net_device *bond_dev,
                                  struct net_device *slave_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
  
          bond_dev->header_ops        = slave_dev->header_ops;
  
          bond_dev->type              = slave_dev->type;
          bond_dev->hard_header_len   = slave_dev->hard_header_len;
          bond_dev->addr_len          = slave_dev->addr_len;
  
          memcpy(bond_dev->broadcast, slave_dev->broadcast,
                  slave_dev->addr_len);
          bond->setup_by_slave = 1;
  }
  
  /* On bonding slaves other than the currently active slave, suppress
   * duplicates except for alb non-mcast/bcast.
   */
  static bool bond_should_deliver_exact_match(struct sk_buff *skb,
                                              struct slave *slave,
                                              struct bonding *bond)
  {
          if (bond_is_slave_inactive(slave)) {
                  if (bond->params.mode == BOND_MODE_ALB &&
                      skb->pkt_type != PACKET_BROADCAST &&
                      skb->pkt_type != PACKET_MULTICAST)
                          return false;
                  return true;
          }
          return false;
  }
  
  static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb)
  {
          struct sk_buff *skb = *pskb;
          struct slave *slave;
          struct bonding *bond;
          int (*recv_probe)(const struct sk_buff *, struct bonding *,
                            struct slave *);
          int ret = RX_HANDLER_ANOTHER;
  
          skb = skb_share_check(skb, GFP_ATOMIC);
          if (unlikely(!skb))
                  return RX_HANDLER_CONSUMED;
  
          *pskb = skb;
  
          slave = bond_slave_get_rcu(skb->dev);
          bond = slave->bond;
  
          if (bond->params.arp_interval)
                  slave->dev->last_rx = jiffies;
  
          recv_probe = ACCESS_ONCE(bond->recv_probe);
          if (recv_probe) {
                  ret = recv_probe(skb, bond, slave);
                  if (ret == RX_HANDLER_CONSUMED) {
                          consume_skb(skb);
                          return ret;
                  }
          }
  
          if (bond_should_deliver_exact_match(skb, slave, bond)) {
                  return RX_HANDLER_EXACT;
          }
  
          skb->dev = bond->dev;
  
          if (bond->params.mode == BOND_MODE_ALB &&
              bond->dev->priv_flags & IFF_BRIDGE_PORT &&
              skb->pkt_type == PACKET_HOST) {
  
                  if (unlikely(skb_cow_head(skb,
                                            skb->data - skb_mac_header(skb)))) {
                          kfree_skb(skb);
                          return RX_HANDLER_CONSUMED;
                  }
                  memcpy(eth_hdr(skb)->h_dest, bond->dev->dev_addr, ETH_ALEN);
          }
  
          return ret;
  }
  
  /* enslave device <slave> to bond device <master> */
  int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          const struct net_device_ops *slave_ops = slave_dev->netdev_ops;
          struct slave *new_slave = NULL;
          struct netdev_hw_addr *ha;
          struct sockaddr addr;
          int link_reporting;
          int res = 0;
  
          if (!bond->params.use_carrier &&
              slave_dev->ethtool_ops->get_link == NULL &&
              slave_ops->ndo_do_ioctl == NULL) {
                  pr_warning("%s: Warning: no link monitoring support for %s\n",
                             bond_dev->name, slave_dev->name);
          }
  
          /* already enslaved */
          if (slave_dev->flags & IFF_SLAVE) {
                  pr_debug("Error, Device was already enslaved\n");
                  return -EBUSY;
          }
  
          /* vlan challenged mutual exclusion */
          /* no need to lock since we're protected by rtnl_lock */
          if (slave_dev->features & NETIF_F_VLAN_CHALLENGED) {
                  pr_debug("%s: NETIF_F_VLAN_CHALLENGED\n", slave_dev->name);
                  if (vlan_uses_dev(bond_dev)) {
                          pr_err("%s: Error: cannot enslave VLAN challenged slave %s on VLAN enabled bond %s\n",
                                 bond_dev->name, slave_dev->name, bond_dev->name);
                          return -EPERM;
                  } else {
                          pr_warning("%s: Warning: enslaved VLAN challenged slave %s. Adding VLANs will be blocked as long as %s is part of bond %s\n",
                                     bond_dev->name, slave_dev->name,
                                     slave_dev->name, bond_dev->name);
                  }
          } else {
                  pr_debug("%s: ! NETIF_F_VLAN_CHALLENGED\n", slave_dev->name);
          }
  
          /*
           * Old ifenslave binaries are no longer supported.  These can
           * be identified with moderate accuracy by the state of the slave:
           * the current ifenslave will set the interface down prior to
           * enslaving it; the old ifenslave will not.
           */
          if ((slave_dev->flags & IFF_UP)) {
                  pr_err("%s is up. This may be due to an out of date ifenslave.\n",
                         slave_dev->name);
                  res = -EPERM;
                  goto err_undo_flags;
          }
  
          /* set bonding device ether type by slave - bonding netdevices are
           * created with ether_setup, so when the slave type is not ARPHRD_ETHER
           * there is a need to override some of the type dependent attribs/funcs.
           *
           * bond ether type mutual exclusion - don't allow slaves of dissimilar
           * ether type (eg ARPHRD_ETHER and ARPHRD_INFINIBAND) share the same bond
           */
          if (bond->slave_cnt == 0) {
                  if (bond_dev->type != slave_dev->type) {
                          pr_debug("%s: change device type from %d to %d\n",
                                   bond_dev->name,
                                   bond_dev->type, slave_dev->type);
  
                          res = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE,
                                                         bond_dev);
                          res = notifier_to_errno(res);
                          if (res) {
                                  pr_err("%s: refused to change device type\n",
                                         bond_dev->name);
                                  res = -EBUSY;
                                  goto err_undo_flags;
                          }
  
                          /* Flush unicast and multicast addresses */
                          dev_uc_flush(bond_dev);
                          dev_mc_flush(bond_dev);
  
                          if (slave_dev->type != ARPHRD_ETHER)
                                  bond_setup_by_slave(bond_dev, slave_dev);
                          else {
                                  ether_setup(bond_dev);
                                  bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
                          }
  
                          call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE,
                                                   bond_dev);
                  }
          } else if (bond_dev->type != slave_dev->type) {
                  pr_err("%s ether type (%d) is different from other slaves (%d), can not enslave it.\n",
                         slave_dev->name,
                         slave_dev->type, bond_dev->type);
                  res = -EINVAL;
                  goto err_undo_flags;
          }
  
          if (slave_ops->ndo_set_mac_address == NULL) {
                  if (bond->slave_cnt == 0) {
                          pr_warning("%s: Warning: The first slave device specified does not support setting the MAC address. Setting fail_over_mac to active.",
                                     bond_dev->name);
                          bond->params.fail_over_mac = BOND_FOM_ACTIVE;
                  } else if (bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
                          pr_err("%s: Error: The slave device specified does not support setting the MAC address, but fail_over_mac is not set to active.\n",
                                 bond_dev->name);
                          res = -EOPNOTSUPP;
                          goto err_undo_flags;
                  }
          }
  
          call_netdevice_notifiers(NETDEV_JOIN, slave_dev);
  
          /* If this is the first slave, then we need to set the master's hardware
           * address to be the same as the slave's. */
          if (is_zero_ether_addr(bond->dev->dev_addr))
                  memcpy(bond->dev->dev_addr, slave_dev->dev_addr,
                         slave_dev->addr_len);
  
  
          new_slave = kzalloc(sizeof(struct slave), GFP_KERNEL);
          if (!new_slave) {
                  res = -ENOMEM;
                  goto err_undo_flags;
          }
  
          /*
           * Set the new_slave's queue_id to be zero.  Queue ID mapping
           * is set via sysfs or module option if desired.
           */
          new_slave->queue_id = 0;
  
          /* Save slave's original mtu and then set it to match the bond */
          new_slave->original_mtu = slave_dev->mtu;
          res = dev_set_mtu(slave_dev, bond->dev->mtu);
          if (res) {
                  pr_debug("Error %d calling dev_set_mtu\n", res);
                  goto err_free;
          }
  
          /*
           * Save slave's original ("permanent") mac address for modes
           * that need it, and for restoring it upon release, and then
           * set it to the master's address
           */
          memcpy(new_slave->perm_hwaddr, slave_dev->dev_addr, ETH_ALEN);
  
          if (!bond->params.fail_over_mac) {
                  /*
                   * Set slave to master's mac address.  The application already
                   * set the master's mac address to that of the first slave
                   */
                  memcpy(addr.sa_data, bond_dev->dev_addr, bond_dev->addr_len);
                  addr.sa_family = slave_dev->type;
                  res = dev_set_mac_address(slave_dev, &addr);
                  if (res) {
                          pr_debug("Error %d calling set_mac_address\n", res);
                          goto err_restore_mtu;
                  }
          }
  
          res = netdev_set_bond_master(slave_dev, bond_dev);
          if (res) {
                  pr_debug("Error %d calling netdev_set_bond_master\n", res);
                  goto err_restore_mac;
          }
  
          /* open the slave since the application closed it */
          res = dev_open(slave_dev);
          if (res) {
                  pr_debug("Opening slave %s failed\n", slave_dev->name);
                  goto err_unset_master;
          }
  
          new_slave->bond = bond;
          new_slave->dev = slave_dev;
          slave_dev->priv_flags |= IFF_BONDING;
  
          if (bond_is_lb(bond)) {
                  /* bond_alb_init_slave() must be called before all other stages since
                   * it might fail and we do not want to have to undo everything
                   */
                  res = bond_alb_init_slave(bond, new_slave);
                  if (res)
                          goto err_close;
          }
  
          /* If the mode USES_PRIMARY, then the new slave gets the
           * master's promisc (and mc) settings only if it becomes the
           * curr_active_slave, and that is taken care of later when calling
           * bond_change_active()
           */
          if (!USES_PRIMARY(bond->params.mode)) {
                  /* set promiscuity level to new slave */
                  if (bond_dev->flags & IFF_PROMISC) {
                          res = dev_set_promiscuity(slave_dev, 1);
                          if (res)
                                  goto err_close;
                  }
  
                  /* set allmulti level to new slave */
                  if (bond_dev->flags & IFF_ALLMULTI) {
                          res = dev_set_allmulti(slave_dev, 1);
                          if (res)
                                  goto err_close;
                  }
  
                  netif_addr_lock_bh(bond_dev);
                  /* upload master's mc_list to new slave */
                  netdev_for_each_mc_addr(ha, bond_dev)
                          dev_mc_add(slave_dev, ha->addr);
                  netif_addr_unlock_bh(bond_dev);
          }
  
          if (bond->params.mode == BOND_MODE_8023AD) {
                  /* add lacpdu mc addr to mc list */
                  u8 lacpdu_multicast[ETH_ALEN] = MULTICAST_LACPDU_ADDR;
  
                  dev_mc_add(slave_dev, lacpdu_multicast);
          }
  
          bond_add_vlans_on_slave(bond, slave_dev);
  
          write_lock_bh(&bond->lock);
  
          bond_attach_slave(bond, new_slave);
  
          new_slave->delay = 0;
          new_slave->link_failure_count = 0;
  
          write_unlock_bh(&bond->lock);
  
          bond_compute_features(bond);
  
          read_lock(&bond->lock);
  
          new_slave->last_arp_rx = jiffies -
                  (msecs_to_jiffies(bond->params.arp_interval) + 1);
  
          if (bond->params.miimon && !bond->params.use_carrier) {
                  link_reporting = bond_check_dev_link(bond, slave_dev, 1);
  
                  if ((link_reporting == -1) && !bond->params.arp_interval) {
                          /*
                           * miimon is set but a bonded network driver
                           * does not support ETHTOOL/MII and
                           * arp_interval is not set.  Note: if
                           * use_carrier is enabled, we will never go
                           * here (because netif_carrier is always
                           * supported); thus, we don't need to change
                           * the messages for netif_carrier.
                           */
                          pr_warning("%s: Warning: MII and ETHTOOL support not available for interface %s, and arp_interval/arp_ip_target module parameters not specified, thus bonding will not detect link failures! see bonding.txt for details.\n",
                                 bond_dev->name, slave_dev->name);
                  } else if (link_reporting == -1) {
                          /* unable get link status using mii/ethtool */
                          pr_warning("%s: Warning: can't get link status from interface %s; the network driver associated with this interface does not support MII or ETHTOOL link status reporting, thus miimon has no effect on this interface.\n",
                                     bond_dev->name, slave_dev->name);
                  }
          }
  
          /* check for initial state */
          if (bond->params.miimon) {
                  if (bond_check_dev_link(bond, slave_dev, 0) == BMSR_LSTATUS) {
                          if (bond->params.updelay) {
                                  new_slave->link = BOND_LINK_BACK;
                                  new_slave->delay = bond->params.updelay;
                          } else {
                                  new_slave->link = BOND_LINK_UP;
                          }
                  } else {
                          new_slave->link = BOND_LINK_DOWN;
                  }
          } else if (bond->params.arp_interval) {
                  new_slave->link = (netif_carrier_ok(slave_dev) ?
                          BOND_LINK_UP : BOND_LINK_DOWN);
          } else {
                  new_slave->link = BOND_LINK_UP;
          }
  
          if (new_slave->link != BOND_LINK_DOWN)
                  new_slave->jiffies = jiffies;
          pr_debug("Initial state of slave_dev is BOND_LINK_%s\n",
                  new_slave->link == BOND_LINK_DOWN ? "DOWN" :
                          (new_slave->link == BOND_LINK_UP ? "UP" : "BACK"));
  
          bond_update_speed_duplex(new_slave);
  
          if (USES_PRIMARY(bond->params.mode) && bond->params.primary[0]) {
                  /* if there is a primary slave, remember it */
                  if (strcmp(bond->params.primary, new_slave->dev->name) == 0) {
                          bond->primary_slave = new_slave;
                          bond->force_primary = true;
                  }
          }
  
          write_lock_bh(&bond->curr_slave_lock);
  
          switch (bond->params.mode) {
          case BOND_MODE_ACTIVEBACKUP:
                  bond_set_slave_inactive_flags(new_slave);
                  bond_select_active_slave(bond);
                  break;
          case BOND_MODE_8023AD:
                  /* in 802.3ad mode, the internal mechanism
                   * will activate the slaves in the selected
                   * aggregator
                   */
                  bond_set_slave_inactive_flags(new_slave);
                  /* if this is the first slave */
                  if (bond->slave_cnt == 1) {
                          SLAVE_AD_INFO(new_slave).id = 1;
                          /* Initialize AD with the number of times that the AD timer is called in 1 second
                           * can be called only after the mac address of the bond is set
                           */
                          bond_3ad_initialize(bond, 1000/AD_TIMER_INTERVAL);
                  } else {
                          SLAVE_AD_INFO(new_slave).id =
                                  SLAVE_AD_INFO(new_slave->prev).id + 1;
                  }
  
                  bond_3ad_bind_slave(new_slave);
                  break;
          case BOND_MODE_TLB:
          case BOND_MODE_ALB:
                  bond_set_active_slave(new_slave);
                  bond_set_slave_inactive_flags(new_slave);
                  bond_select_active_slave(bond);
                  break;
          default:
                  pr_debug("This slave is always active in trunk mode\n");
  
                  /* always active in trunk mode */
                  bond_set_active_slave(new_slave);
  
                  /* In trunking mode there is little meaning to curr_active_slave
                   * anyway (it holds no special properties of the bond device),
                   * so we can change it without calling change_active_interface()
                   */
                  if (!bond->curr_active_slave && new_slave->link == BOND_LINK_UP)
                          bond->curr_active_slave = new_slave;
  
                  break;
          } /* switch(bond_mode) */
  
          write_unlock_bh(&bond->curr_slave_lock);
  
          bond_set_carrier(bond);
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
          slave_dev->npinfo = bond_netpoll_info(bond);
          if (slave_dev->npinfo) {
                  if (slave_enable_netpoll(new_slave)) {
                          read_unlock(&bond->lock);
                          pr_info("Error, %s: master_dev is using netpoll, "
                                   "but new slave device does not support netpoll.\n",
                                   bond_dev->name);
                          res = -EBUSY;
                          goto err_detach;
                  }
          }
  #endif
  
          read_unlock(&bond->lock);
  
          res = bond_create_slave_symlinks(bond_dev, slave_dev);
          if (res)
                  goto err_detach;
  
          res = netdev_rx_handler_register(slave_dev, bond_handle_frame,
                                           new_slave);
          if (res) {
                  pr_debug("Error %d calling netdev_rx_handler_register\n", res);
                  goto err_dest_symlinks;
          }
  
          pr_info("%s: enslaving %s as a%s interface with a%s link.\n",
                  bond_dev->name, slave_dev->name,
                  bond_is_active_slave(new_slave) ? "n active" : " backup",
                  new_slave->link != BOND_LINK_DOWN ? "n up" : " down");
  
          /* enslave is successful */
          return 0;
  
  /* Undo stages on error */
  err_dest_symlinks:
          bond_destroy_slave_symlinks(bond_dev, slave_dev);
  
  err_detach:
          write_lock_bh(&bond->lock);
          bond_detach_slave(bond, new_slave);
          write_unlock_bh(&bond->lock);
  
  err_close:
          dev_close(slave_dev);
  
  err_unset_master:
          netdev_set_bond_master(slave_dev, NULL);
  
  err_restore_mac:
          if (!bond->params.fail_over_mac) {
                  /* XXX TODO - fom follow mode needs to change master's
                   * MAC if this slave's MAC is in use by the bond, or at
                   * least print a warning.
                   */
                  memcpy(addr.sa_data, new_slave->perm_hwaddr, ETH_ALEN);
                  addr.sa_family = slave_dev->type;
                  dev_set_mac_address(slave_dev, &addr);
          }
  
  err_restore_mtu:
          dev_set_mtu(slave_dev, new_slave->original_mtu);
  
  err_free:
          kfree(new_slave);
  
  err_undo_flags:
          bond_compute_features(bond);
  
          return res;
  }
  
  /*
   * Try to release the slave device <slave> from the bond device <master>
   * It is legal to access curr_active_slave without a lock because all the function
   * is write-locked.
   *
   * The rules for slave state should be:
   *   for Active/Backup:
   *     Active stays on all backups go down
   *   for Bonded connections:
   *     The first up interface should be left on and all others downed.
   */
  int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave, *oldcurrent;
          struct sockaddr addr;
          netdev_features_t old_features = bond_dev->features;
  
          /* slave is not a slave or master is not master of this slave */
          if (!(slave_dev->flags & IFF_SLAVE) ||
              (slave_dev->master != bond_dev)) {
                  pr_err("%s: Error: cannot release %s.\n",
                         bond_dev->name, slave_dev->name);
                  return -EINVAL;
          }
  
          block_netpoll_tx();
          call_netdevice_notifiers(NETDEV_RELEASE, bond_dev);
          write_lock_bh(&bond->lock);
  
          slave = bond_get_slave_by_dev(bond, slave_dev);
          if (!slave) {
                  /* not a slave of this bond */
                  pr_info("%s: %s not enslaved\n",
                          bond_dev->name, slave_dev->name);
                  write_unlock_bh(&bond->lock);
                  unblock_netpoll_tx();
                  return -EINVAL;
          }
  
          /* unregister rx_handler early so bond_handle_frame wouldn't be called
           * for this slave anymore.
           */
          netdev_rx_handler_unregister(slave_dev);
          write_unlock_bh(&bond->lock);
          synchronize_net();
          write_lock_bh(&bond->lock);
  
          if (!bond->params.fail_over_mac) {
                  if (ether_addr_equal(bond_dev->dev_addr, slave->perm_hwaddr) &&
                      bond->slave_cnt > 1)
                          pr_warning("%s: Warning: the permanent HWaddr of %s - %pM - is still in use by %s. Set the HWaddr of %s to a different address to avoid conflicts.\n",
                                     bond_dev->name, slave_dev->name,
                                     slave->perm_hwaddr,
                                     bond_dev->name, slave_dev->name);
          }
  
          /* Inform AD package of unbinding of slave. */
          if (bond->params.mode == BOND_MODE_8023AD) {
                  /* must be called before the slave is
                   * detached from the list
                   */
                  bond_3ad_unbind_slave(slave);
          }
  
          pr_info("%s: releasing %s interface %s\n",
                  bond_dev->name,
                  bond_is_active_slave(slave) ? "active" : "backup",
                  slave_dev->name);
  
          oldcurrent = bond->curr_active_slave;
  
          bond->current_arp_slave = NULL;
  
          /* release the slave from its bond */
          bond_detach_slave(bond, slave);
  
          if (bond->primary_slave == slave)
                  bond->primary_slave = NULL;
  
          if (oldcurrent == slave)
                  bond_change_active_slave(bond, NULL);
  
          if (bond_is_lb(bond)) {
                  /* Must be called only after the slave has been
                   * detached from the list and the curr_active_slave
                   * has been cleared (if our_slave == old_current),
                   * but before a new active slave is selected.
                   */
                  write_unlock_bh(&bond->lock);
                  bond_alb_deinit_slave(bond, slave);
                  write_lock_bh(&bond->lock);
          }
  
          if (oldcurrent == slave) {
                  /*
                   * Note that we hold RTNL over this sequence, so there
                   * is no concern that another slave add/remove event
                   * will interfere.
                   */
                  write_unlock_bh(&bond->lock);
                  read_lock(&bond->lock);
                  write_lock_bh(&bond->curr_slave_lock);
  
                  bond_select_active_slave(bond);
  
                  write_unlock_bh(&bond->curr_slave_lock);
                  read_unlock(&bond->lock);
                  write_lock_bh(&bond->lock);
          }
  
          if (bond->slave_cnt == 0) {
                  bond_set_carrier(bond);
  
                  /* if the last slave was removed, zero the mac address
                   * of the master so it will be set by the application
                   * to the mac address of the first slave
                   */
                  memset(bond_dev->dev_addr, 0, bond_dev->addr_len);
  
                  if (bond_vlan_used(bond)) {
                          pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n",
                                     bond_dev->name, bond_dev->name);
                          pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n",
                                     bond_dev->name);
                  }
          }
  
          write_unlock_bh(&bond->lock);
          unblock_netpoll_tx();
  
          if (bond->slave_cnt == 0)
                  call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
  
          bond_compute_features(bond);
          if (!(bond_dev->features & NETIF_F_VLAN_CHALLENGED) &&
              (old_features & NETIF_F_VLAN_CHALLENGED))
                  pr_info("%s: last VLAN challenged slave %s left bond %s. VLAN blocking is removed\n",
                          bond_dev->name, slave_dev->name, bond_dev->name);
  
          /* must do this from outside any spinlocks */
          bond_destroy_slave_symlinks(bond_dev, slave_dev);
  
          bond_del_vlans_from_slave(bond, slave_dev);
  
          /* If the mode USES_PRIMARY, then we should only remove its
           * promisc and mc settings if it was the curr_active_slave, but that was
           * already taken care of above when we detached the slave
           */
          if (!USES_PRIMARY(bond->params.mode)) {
                  /* unset promiscuity level from slave */
                  if (bond_dev->flags & IFF_PROMISC)
                          dev_set_promiscuity(slave_dev, -1);
  
                  /* unset allmulti level from slave */
                  if (bond_dev->flags & IFF_ALLMULTI)
                          dev_set_allmulti(slave_dev, -1);
  
                  /* flush master's mc_list from slave */
                  netif_addr_lock_bh(bond_dev);
                  bond_mc_list_flush(bond_dev, slave_dev);
                  netif_addr_unlock_bh(bond_dev);
          }
  
          netdev_set_bond_master(slave_dev, NULL);
  
          slave_disable_netpoll(slave);
  
          /* close slave before restoring its mac address */
          dev_close(slave_dev);
  
          if (bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
                  /* restore original ("permanent") mac address */
                  memcpy(addr.sa_data, slave->perm_hwaddr, ETH_ALEN);
                  addr.sa_family = slave_dev->type;
                  dev_set_mac_address(slave_dev, &addr);
          }
  
          dev_set_mtu(slave_dev, slave->original_mtu);
  
          slave_dev->priv_flags &= ~IFF_BONDING;
  
          kfree(slave);
  
          return 0;  /* deletion OK */
  }
  
  /*
  * First release a slave and then destroy the bond if no more slaves are left.
  * Must be under rtnl_lock when this function is called.
  */
  static int  bond_release_and_destroy(struct net_device *bond_dev,
                                       struct net_device *slave_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          int ret;
  
          ret = bond_release(bond_dev, slave_dev);
          if ((ret == 0) && (bond->slave_cnt == 0)) {
                  bond_dev->priv_flags |= IFF_DISABLE_NETPOLL;
                  pr_info("%s: destroying bond %s.\n",
                          bond_dev->name, bond_dev->name);
                  unregister_netdevice(bond_dev);
          }
          return ret;
  }
  
  /*
   * This function releases all slaves.
   */
  static int bond_release_all(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave;
          struct net_device *slave_dev;
          struct sockaddr addr;
  
          write_lock_bh(&bond->lock);
  
          netif_carrier_off(bond_dev);
  
          if (bond->slave_cnt == 0)
                  goto out;
  
          bond->current_arp_slave = NULL;
          bond->primary_slave = NULL;
          bond_change_active_slave(bond, NULL);
  
          while ((slave = bond->first_slave) != NULL) {
                  /* Inform AD package of unbinding of slave
                   * before slave is detached from the list.
                   */
                  if (bond->params.mode == BOND_MODE_8023AD)
                          bond_3ad_unbind_slave(slave);
  
                  slave_dev = slave->dev;
                  bond_detach_slave(bond, slave);
  
                  /* now that the slave is detached, unlock and perform
                   * all the undo steps that should not be called from
                   * within a lock.
                   */
                  write_unlock_bh(&bond->lock);
  
                  /* unregister rx_handler early so bond_handle_frame wouldn't
                   * be called for this slave anymore.
                   */
                  netdev_rx_handler_unregister(slave_dev);
                  synchronize_net();
  
                  if (bond_is_lb(bond)) {
                          /* must be called only after the slave
                           * has been detached from the list
                           */
                          bond_alb_deinit_slave(bond, slave);
                  }
  
                  bond_destroy_slave_symlinks(bond_dev, slave_dev);
                  bond_del_vlans_from_slave(bond, slave_dev);
  
                  /* If the mode USES_PRIMARY, then we should only remove its
                   * promisc and mc settings if it was the curr_active_slave, but that was
                   * already taken care of above when we detached the slave
                   */
                  if (!USES_PRIMARY(bond->params.mode)) {
                          /* unset promiscuity level from slave */
                          if (bond_dev->flags & IFF_PROMISC)
                                  dev_set_promiscuity(slave_dev, -1);
  
                          /* unset allmulti level from slave */
                          if (bond_dev->flags & IFF_ALLMULTI)
                                  dev_set_allmulti(slave_dev, -1);
  
                          /* flush master's mc_list from slave */
                          netif_addr_lock_bh(bond_dev);
                          bond_mc_list_flush(bond_dev, slave_dev);
                          netif_addr_unlock_bh(bond_dev);
                  }
  
                  netdev_set_bond_master(slave_dev, NULL);
  
                  slave_disable_netpoll(slave);
  
                  /* close slave before restoring its mac address */
                  dev_close(slave_dev);
  
                  if (!bond->params.fail_over_mac) {
                          /* restore original ("permanent") mac address*/
                          memcpy(addr.sa_data, slave->perm_hwaddr, ETH_ALEN);
                          addr.sa_family = slave_dev->type;
                          dev_set_mac_address(slave_dev, &addr);
                  }
  
                  kfree(slave);
  
                  /* re-acquire the lock before getting the next slave */
                  write_lock_bh(&bond->lock);
          }
  
          /* zero the mac address of the master so it will be
           * set by the application to the mac address of the
           * first slave
           */
          memset(bond_dev->dev_addr, 0, bond_dev->addr_len);
  
          if (bond_vlan_used(bond)) {
                  pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n",
                             bond_dev->name, bond_dev->name);
                  pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n",
                             bond_dev->name);
          }
  
          pr_info("%s: released all slaves\n", bond_dev->name);
  
  out:
          write_unlock_bh(&bond->lock);
  
          bond_compute_features(bond);
  
          return 0;
  }
  
  /*
   * This function changes the active slave to slave <slave_dev>.
   * It returns -EINVAL in the following cases.
   *  - <slave_dev> is not found in the list.
   *  - There is not active slave now.
   *  - <slave_dev> is already active.
   *  - The link state of <slave_dev> is not BOND_LINK_UP.
   *  - <slave_dev> is not running.
   * In these cases, this function does nothing.
   * In the other cases, current_slave pointer is changed and 0 is returned.
   */
  static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_device *slave_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *old_active = NULL;
          struct slave *new_active = NULL;
          int res = 0;
  
          if (!USES_PRIMARY(bond->params.mode))
                  return -EINVAL;
  
          /* Verify that master_dev is indeed the master of slave_dev */
          if (!(slave_dev->flags & IFF_SLAVE) || (slave_dev->master != bond_dev))
                  return -EINVAL;
  
          read_lock(&bond->lock);
  
          read_lock(&bond->curr_slave_lock);
          old_active = bond->curr_active_slave;
          read_unlock(&bond->curr_slave_lock);
  
          new_active = bond_get_slave_by_dev(bond, slave_dev);
  
          /*
           * Changing to the current active: do nothing; return success.
           */
          if (new_active && (new_active == old_active)) {
                  read_unlock(&bond->lock);
                  return 0;
          }
  
          if ((new_active) &&
              (old_active) &&
              (new_active->link == BOND_LINK_UP) &&
              IS_UP(new_active->dev)) {
                  block_netpoll_tx();
                  write_lock_bh(&bond->curr_slave_lock);
                  bond_change_active_slave(bond, new_active);
                  write_unlock_bh(&bond->curr_slave_lock);
                  unblock_netpoll_tx();
          } else
                  res = -EINVAL;
  
          read_unlock(&bond->lock);
  
          return res;
  }
  
  static int bond_info_query(struct net_device *bond_dev, struct ifbond *info)
  {
          struct bonding *bond = netdev_priv(bond_dev);
  
          info->bond_mode = bond->params.mode;
          info->miimon = bond->params.miimon;
  
          read_lock(&bond->lock);
          info->num_slaves = bond->slave_cnt;
          read_unlock(&bond->lock);
  
          return 0;
  }
  
  static int bond_slave_info_query(struct net_device *bond_dev, struct ifslave *info)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave;
          int i, res = -ENODEV;
  
          read_lock(&bond->lock);
  
          bond_for_each_slave(bond, slave, i) {
                  if (i == (int)info->slave_id) {
                          res = 0;
                          strcpy(info->slave_name, slave->dev->name);
                          info->link = slave->link;
                          info->state = bond_slave_state(slave);
                          info->link_failure_count = slave->link_failure_count;
                          break;
                  }
          }
  
          read_unlock(&bond->lock);
  
          return res;
  }
  
  /*-------------------------------- Monitoring -------------------------------*/
  
  
  static int bond_miimon_inspect(struct bonding *bond)
  {
          struct slave *slave;
          int i, link_state, commit = 0;
          bool ignore_updelay;
  
          ignore_updelay = !bond->curr_active_slave ? true : false;
  
          bond_for_each_slave(bond, slave, i) {
                  slave->new_link = BOND_LINK_NOCHANGE;
  
                  link_state = bond_check_dev_link(bond, slave->dev, 0);
  
                  switch (slave->link) {
                  case BOND_LINK_UP:
                          if (link_state)
                                  continue;
  
                          slave->link = BOND_LINK_FAIL;
                          slave->delay = bond->params.downdelay;
                          if (slave->delay) {
                                  pr_info("%s: link status down for %sinterface %s, disabling it in %d ms.\n",
                                          bond->dev->name,
                                          (bond->params.mode ==
                                           BOND_MODE_ACTIVEBACKUP) ?
                                          (bond_is_active_slave(slave) ?
                                           "active " : "backup ") : "",
                                          slave->dev->name,
                                          bond->params.downdelay * bond->params.miimon);
                          }
                          /*FALLTHRU*/
                  case BOND_LINK_FAIL:
                          if (link_state) {
                                  /*
                                   * recovered before downdelay expired
                                   */
                                  slave->link = BOND_LINK_UP;
                                  slave->jiffies = jiffies;
                                  pr_info("%s: link status up again after %d ms for interface %s.\n",
                                          bond->dev->name,
                                          (bond->params.downdelay - slave->delay) *
                                          bond->params.miimon,
                                          slave->dev->name);
                                  continue;
                          }
  
                          if (slave->delay <= 0) {
                                  slave->new_link = BOND_LINK_DOWN;
                                  commit++;
                                  continue;
                          }
  
                          slave->delay--;
                          break;
  
                  case BOND_LINK_DOWN:
                          if (!link_state)
                                  continue;
  
                          slave->link = BOND_LINK_BACK;
                          slave->delay = bond->params.updelay;
  
                          if (slave->delay) {
                                  pr_info("%s: link status up for interface %s, enabling it in %d ms.\n",
                                          bond->dev->name, slave->dev->name,
                                          ignore_updelay ? 0 :
                                          bond->params.updelay *
                                          bond->params.miimon);
                          }
                          /*FALLTHRU*/
                  case BOND_LINK_BACK:
                          if (!link_state) {
                                  slave->link = BOND_LINK_DOWN;
                                  pr_info("%s: link status down again after %d ms for interface %s.\n",
                                          bond->dev->name,
                                          (bond->params.updelay - slave->delay) *
                                          bond->params.miimon,
                                          slave->dev->name);
  
                                  continue;
                          }
  
                          if (ignore_updelay)
                                  slave->delay = 0;
  
                          if (slave->delay <= 0) {
                                  slave->new_link = BOND_LINK_UP;
                                  commit++;
                                  ignore_updelay = false;
                                  continue;
                          }
  
                          slave->delay--;
                          break;
                  }
          }
  
          return commit;
  }
  
  static void bond_miimon_commit(struct bonding *bond)
  {
          struct slave *slave;
          int i;
  
          bond_for_each_slave(bond, slave, i) {
                  switch (slave->new_link) {
                  case BOND_LINK_NOCHANGE:
                          continue;
  
                  case BOND_LINK_UP:
                          slave->link = BOND_LINK_UP;
                          slave->jiffies = jiffies;
  
                          if (bond->params.mode == BOND_MODE_8023AD) {
                                  /* prevent it from being the active one */
                                  bond_set_backup_slave(slave);
                          } else if (bond->params.mode != BOND_MODE_ACTIVEBACKUP) {
                                  /* make it immediately active */
                                  bond_set_active_slave(slave);
                          } else if (slave != bond->primary_slave) {
                                  /* prevent it from being the active one */
                                  bond_set_backup_slave(slave);
                          }
  
                          bond_update_speed_duplex(slave);
  
                          pr_info("%s: link status definitely up for interface %s, %u Mbps %s duplex.\n",
                                  bond->dev->name, slave->dev->name,
                                  slave->speed, slave->duplex ? "full" : "half");
  
                          /* notify ad that the link status has changed */
                          if (bond->params.mode == BOND_MODE_8023AD)
                                  bond_3ad_handle_link_change(slave, BOND_LINK_UP);
  
                          if (bond_is_lb(bond))
                                  bond_alb_handle_link_change(bond, slave,
                                                              BOND_LINK_UP);
  
                          if (!bond->curr_active_slave ||
                              (slave == bond->primary_slave))
                                  goto do_failover;
  
                          continue;
  
                  case BOND_LINK_DOWN:
                          if (slave->link_failure_count < UINT_MAX)
                                  slave->link_failure_count++;
  
                          slave->link = BOND_LINK_DOWN;
  
                          if (bond->params.mode == BOND_MODE_ACTIVEBACKUP ||
                              bond->params.mode == BOND_MODE_8023AD)
                                  bond_set_slave_inactive_flags(slave);
  
                          pr_info("%s: link status definitely down for interface %s, disabling it\n",
                                  bond->dev->name, slave->dev->name);
  
                          if (bond->params.mode == BOND_MODE_8023AD)
                                  bond_3ad_handle_link_change(slave,
                                                              BOND_LINK_DOWN);
  
                          if (bond_is_lb(bond))
                                  bond_alb_handle_link_change(bond, slave,
                                                              BOND_LINK_DOWN);
  
                          if (slave == bond->curr_active_slave)
                                  goto do_failover;
  
                          continue;
  
                  default:
                          pr_err("%s: invalid new link %d on slave %s\n",
                                 bond->dev->name, slave->new_link,
                                 slave->dev->name);
                          slave->new_link = BOND_LINK_NOCHANGE;
  
                          continue;
                  }
  
  do_failover:
                  ASSERT_RTNL();
                  block_netpoll_tx();
                  write_lock_bh(&bond->curr_slave_lock);
                  bond_select_active_slave(bond);
                  write_unlock_bh(&bond->curr_slave_lock);
                  unblock_netpoll_tx();
          }
  
          bond_set_carrier(bond);
  }
  
  /*
   * bond_mii_monitor
   *
   * Really a wrapper that splits the mii monitor into two phases: an
   * inspection, then (if inspection indicates something needs to be done)
   * an acquisition of appropriate locks followed by a commit phase to
   * implement whatever link state changes are indicated.
   */
  void bond_mii_monitor(struct work_struct *work)
  {
          struct bonding *bond = container_of(work, struct bonding,
                                              mii_work.work);
          bool should_notify_peers = false;
          unsigned long delay;
  
          read_lock(&bond->lock);
  
          delay = msecs_to_jiffies(bond->params.miimon);
  
          if (bond->slave_cnt == 0)
                  goto re_arm;
  
          should_notify_peers = bond_should_notify_peers(bond);
  
          if (bond_miimon_inspect(bond)) {
                  read_unlock(&bond->lock);
  
                  /* Race avoidance with bond_close cancel of workqueue */
                  if (!rtnl_trylock()) {
                          read_lock(&bond->lock);
                          delay = 1;
                          should_notify_peers = false;
                          goto re_arm;
                  }
  
                  read_lock(&bond->lock);
  
                  bond_miimon_commit(bond);
  
                  read_unlock(&bond->lock);
                  rtnl_unlock();  /* might sleep, hold no other locks */
                  read_lock(&bond->lock);
          }
  
  re_arm:
          if (bond->params.miimon)
                  queue_delayed_work(bond->wq, &bond->mii_work, delay);
  
          read_unlock(&bond->lock);
  
          if (should_notify_peers) {
                  if (!rtnl_trylock()) {
                          read_lock(&bond->lock);
                          bond->send_peer_notif++;
                          read_unlock(&bond->lock);
                          return;
                  }
                  call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);
                  rtnl_unlock();
          }
  }
  
  static int bond_has_this_ip(struct bonding *bond, __be32 ip)
  {
          struct vlan_entry *vlan;
          struct net_device *vlan_dev;
  
          if (ip == bond_confirm_addr(bond->dev, 0, ip))
                  return 1;
  
          list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                  rcu_read_lock();
                  vlan_dev = __vlan_find_dev_deep(bond->dev, vlan->vlan_id);
                  rcu_read_unlock();
                  if (vlan_dev && ip == bond_confirm_addr(vlan_dev, 0, ip))
                          return 1;
          }
  
          return 0;
  }
  
  /*
   * We go to the (large) trouble of VLAN tagging ARP frames because
   * switches in VLAN mode (especially if ports are configured as
   * "native" to a VLAN) might not pass non-tagged frames.
   */
  static void bond_arp_send(struct net_device *slave_dev, int arp_op, __be32 dest_ip, __be32 src_ip, unsigned short vlan_id)
  {
          struct sk_buff *skb;
  
          pr_debug("arp %d on slave %s: dst %x src %x vid %d\n", arp_op,
                   slave_dev->name, dest_ip, src_ip, vlan_id);
  
          skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
                           NULL, slave_dev->dev_addr, NULL);
  
          if (!skb) {
                  pr_err("ARP packet allocation failed\n");
                  return;
          }
          if (vlan_id) {
                  skb = vlan_put_tag(skb, vlan_id);
                  if (!skb) {
                          pr_err("failed to insert VLAN tag\n");
                          return;
                  }
          }
          arp_xmit(skb);
  }
  
  
  static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
  {
          int i, vlan_id;
          __be32 *targets = bond->params.arp_targets;
          struct vlan_entry *vlan;
          struct net_device *vlan_dev = NULL;
          struct rtable *rt;
  
          for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
                  __be32 addr;
                  if (!targets[i])
                          break;
                  pr_debug("basa: target %x\n", targets[i]);
                  if (!bond_vlan_used(bond)) {
                          pr_debug("basa: empty vlan: arp_send\n");
                          addr = bond_confirm_addr(bond->dev, targets[i], 0);
                          bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                                        addr, 0);
                          continue;
                  }
  
                  /*
                   * If VLANs are configured, we do a route lookup to
                   * determine which VLAN interface would be used, so we
                   * can tag the ARP with the proper VLAN tag.
                   */
                  rt = ip_route_output(dev_net(bond->dev), targets[i], 0,
                                       RTO_ONLINK, 0);
                  if (IS_ERR(rt)) {
                          if (net_ratelimit()) {
                                  pr_warning("%s: no route to arp_ip_target %pI4\n",
                                             bond->dev->name, &targets[i]);
                          }
                          continue;
                  }
  
                  /*
                   * This target is not on a VLAN
                   */
                  if (rt->dst.dev == bond->dev) {
                          ip_rt_put(rt);
                          pr_debug("basa: rtdev == bond->dev: arp_send\n");
                          addr = bond_confirm_addr(bond->dev, targets[i], 0);
                          bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                                        addr, 0);
                          continue;
                  }
  
                  vlan_id = 0;
                  list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
                          rcu_read_lock();
                          vlan_dev = __vlan_find_dev_deep(bond->dev,
                                                          vlan->vlan_id);
                          rcu_read_unlock();
                          if (vlan_dev == rt->dst.dev) {
                                  vlan_id = vlan->vlan_id;
                                  pr_debug("basa: vlan match on %s %d\n",
                                         vlan_dev->name, vlan_id);
                                  break;
                          }
                  }
  
                  if (vlan_id && vlan_dev) {
                          ip_rt_put(rt);
                          addr = bond_confirm_addr(vlan_dev, targets[i], 0);
                          bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
                                        addr, vlan_id);
                          continue;
                  }
  
                  if (net_ratelimit()) {
                          pr_warning("%s: no path to arp_ip_target %pI4 via rt.dev %s\n",
                                     bond->dev->name, &targets[i],
                                     rt->dst.dev ? rt->dst.dev->name : "NULL");
                  }
                  ip_rt_put(rt);
          }
  }
  
  static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32 sip, __be32 tip)
  {
          int i;
          __be32 *targets = bond->params.arp_targets;
  
          for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
                  pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip) %d\n",
                           &sip, &tip, i, &targets[i],
                           bond_has_this_ip(bond, tip));
                  if (sip == targets[i]) {
                          if (bond_has_this_ip(bond, tip))
                                  slave->last_arp_rx = jiffies;
                          return;
                  }
          }
  }
  
  static int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
                          struct slave *slave)
  {
          struct arphdr *arp = (struct arphdr *)skb->data;
          unsigned char *arp_ptr;
          __be32 sip, tip;
          int alen;
  
          if (skb->protocol != __cpu_to_be16(ETH_P_ARP))
                  return RX_HANDLER_ANOTHER;
  
          read_lock(&bond->lock);
          alen = arp_hdr_len(bond->dev);
  
          pr_debug("bond_arp_rcv: bond %s skb->dev %s\n",
                   bond->dev->name, skb->dev->name);
  
          if (alen > skb_headlen(skb)) {
                  arp = kmalloc(alen, GFP_ATOMIC);
                  if (!arp)
                          goto out_unlock;
                  if (skb_copy_bits(skb, 0, arp, alen) < 0)
                          goto out_unlock;
          }
  
          if (arp->ar_hln != bond->dev->addr_len ||
              skb->pkt_type == PACKET_OTHERHOST ||
              skb->pkt_type == PACKET_LOOPBACK ||
              arp->ar_hrd != htons(ARPHRD_ETHER) ||
              arp->ar_pro != htons(ETH_P_IP) ||
              arp->ar_pln != 4)
                  goto out_unlock;
  
          arp_ptr = (unsigned char *)(arp + 1);
          arp_ptr += bond->dev->addr_len;
          memcpy(&sip, arp_ptr, 4);
          arp_ptr += 4 + bond->dev->addr_len;
          memcpy(&tip, arp_ptr, 4);
  
          pr_debug("bond_arp_rcv: %s %s/%d av %d sv %d sip %pI4 tip %pI4\n",
                   bond->dev->name, slave->dev->name, bond_slave_state(slave),
                   bond->params.arp_validate, slave_do_arp_validate(bond, slave),
                   &sip, &tip);
  
          /*
           * Backup slaves won't see the ARP reply, but do come through
           * here for each ARP probe (so we swap the sip/tip to validate
           * the probe).  In a "redundant switch, common router" type of
           * configuration, the ARP probe will (hopefully) travel from
           * the active, through one switch, the router, then the other
           * switch before reaching the backup.
           */
          if (bond_is_active_slave(slave))
                  bond_validate_arp(bond, slave, sip, tip);
          else
                  bond_validate_arp(bond, slave, tip, sip);
  
  out_unlock:
          read_unlock(&bond->lock);
          if (arp != (struct arphdr *)skb->data)
                  kfree(arp);
          return RX_HANDLER_ANOTHER;
  }
  
  /*
   * this function is called regularly to monitor each slave's link
   * ensuring that traffic is being sent and received when arp monitoring
   * is used in load-balancing mode. if the adapter has been dormant, then an
   * arp is transmitted to generate traffic. see activebackup_arp_monitor for
   * arp monitoring in active backup mode.
   */
  void bond_loadbalance_arp_mon(struct work_struct *work)
  {
          struct bonding *bond = container_of(work, struct bonding,
                                              arp_work.work);
          struct slave *slave, *oldcurrent;
          int do_failover = 0;
          int delta_in_ticks, extra_ticks;
          int i;
  
          read_lock(&bond->lock);
  
          delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
          extra_ticks = delta_in_ticks / 2;
  
          if (bond->slave_cnt == 0)
                  goto re_arm;
  
          read_lock(&bond->curr_slave_lock);
          oldcurrent = bond->curr_active_slave;
          read_unlock(&bond->curr_slave_lock);
  
          /* see if any of the previous devices are up now (i.e. they have
           * xmt and rcv traffic). the curr_active_slave does not come into
           * the picture unless it is null. also, slave->jiffies is not needed
           * here because we send an arp on each slave and give a slave as
           * long as it needs to get the tx/rx within the delta.
           * TODO: what about up/down delay in arp mode? it wasn't here before
           *       so it can wait
           */
          bond_for_each_slave(bond, slave, i) {
                  unsigned long trans_start = dev_trans_start(slave->dev);
  
                  if (slave->link != BOND_LINK_UP) {
                          if (time_in_range(jiffies,
                                  trans_start - delta_in_ticks,
                                  trans_start + delta_in_ticks + extra_ticks) &&
                              time_in_range(jiffies,
                                  slave->dev->last_rx - delta_in_ticks,
                                  slave->dev->last_rx + delta_in_ticks + extra_ticks)) {
  
                                  slave->link  = BOND_LINK_UP;
                                  bond_set_active_slave(slave);
  
                                  /* primary_slave has no meaning in round-robin
                                   * mode. the window of a slave being up and
                                   * curr_active_slave being null after enslaving
                                   * is closed.
                                   */
                                  if (!oldcurrent) {
                                          pr_info("%s: link status definitely up for interface %s, ",
                                                  bond->dev->name,
                                                  slave->dev->name);
                                          do_failover = 1;
                                  } else {
                                          pr_info("%s: interface %s is now up\n",
                                                  bond->dev->name,
                                                  slave->dev->name);
                                  }
                          }
                  } else {
                          /* slave->link == BOND_LINK_UP */
  
                          /* not all switches will respond to an arp request
                           * when the source ip is 0, so don't take the link down
                           * if we don't know our ip yet
                           */
                          if (!time_in_range(jiffies,
                                  trans_start - delta_in_ticks,
                                  trans_start + 2 * delta_in_ticks + extra_ticks) ||
                              !time_in_range(jiffies,
                                  slave->dev->last_rx - delta_in_ticks,
                                  slave->dev->last_rx + 2 * delta_in_ticks + extra_ticks)) {
  
                                  slave->link  = BOND_LINK_DOWN;
                                  bond_set_backup_slave(slave);
  
                                  if (slave->link_failure_count < UINT_MAX)
                                          slave->link_failure_count++;
  
                                  pr_info("%s: interface %s is now down.\n",
                                          bond->dev->name,
                                          slave->dev->name);
  
                                  if (slave == oldcurrent)
                                          do_failover = 1;
                          }
                  }
  
                  /* note: if switch is in round-robin mode, all links
                   * must tx arp to ensure all links rx an arp - otherwise
                   * links may oscillate or not come up at all; if switch is
                   * in something like xor mode, there is nothing we can
                   * do - all replies will be rx'ed on same link causing slaves
                   * to be unstable during low/no traffic periods
                   */
                  if (IS_UP(slave->dev))
                          bond_arp_send_all(bond, slave);
          }
  
          if (do_failover) {
                  block_netpoll_tx();
                  write_lock_bh(&bond->curr_slave_lock);
  
                  bond_select_active_slave(bond);
  
                  write_unlock_bh(&bond->curr_slave_lock);
                  unblock_netpoll_tx();
          }
  
  re_arm:
          if (bond->params.arp_interval)
                  queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
  
          read_unlock(&bond->lock);
  }
  
  /*
   * Called to inspect slaves for active-backup mode ARP monitor link state
   * changes.  Sets new_link in slaves to specify what action should take
   * place for the slave.  Returns 0 if no changes are found, >0 if changes
   * to link states must be committed.
   *
   * Called with bond->lock held for read.
   */
  static int bond_ab_arp_inspect(struct bonding *bond, int delta_in_ticks)
  {
          struct slave *slave;
          int i, commit = 0;
          unsigned long trans_start;
          int extra_ticks;
  
          /* All the time comparisons below need some extra time. Otherwise, on
           * fast networks the ARP probe/reply may arrive within the same jiffy
           * as it was sent.  Then, the next time the ARP monitor is run, one
           * arp_interval will already have passed in the comparisons.
           */
          extra_ticks = delta_in_ticks / 2;
  
          bond_for_each_slave(bond, slave, i) {
                  slave->new_link = BOND_LINK_NOCHANGE;
  
                  if (slave->link != BOND_LINK_UP) {
                          if (time_in_range(jiffies,
                                  slave_last_rx(bond, slave) - delta_in_ticks,
                                  slave_last_rx(bond, slave) + delta_in_ticks + extra_ticks)) {
  
                                  slave->new_link = BOND_LINK_UP;
                                  commit++;
                          }
  
                          continue;
                  }
  
                  /*
                   * Give slaves 2*delta after being enslaved or made
                   * active.  This avoids bouncing, as the last receive
                   * times need a full ARP monitor cycle to be updated.
                   */
                  if (time_in_range(jiffies,
                                    slave->jiffies - delta_in_ticks,
                                    slave->jiffies + 2 * delta_in_ticks + extra_ticks))
                          continue;
  
                  /*
                   * Backup slave is down if:
                   * - No current_arp_slave AND
                   * - more than 3*delta since last receive AND
                   * - the bond has an IP address
                   *
                   * Note: a non-null current_arp_slave indicates
                   * the curr_active_slave went down and we are
                   * searching for a new one; under this condition
                   * we only take the curr_active_slave down - this
                   * gives each slave a chance to tx/rx traffic
                   * before being taken out
                   */
                  if (!bond_is_active_slave(slave) &&
                      !bond->current_arp_slave &&
                      !time_in_range(jiffies,
                          slave_last_rx(bond, slave) - delta_in_ticks,
                          slave_last_rx(bond, slave) + 3 * delta_in_ticks + extra_ticks)) {
  
                          slave->new_link = BOND_LINK_DOWN;
                          commit++;
                  }
  
                  /*
                   * Active slave is down if:
                   * - more than 2*delta since transmitting OR
                   * - (more than 2*delta since receive AND
                   *    the bond has an IP address)
                   */
                  trans_start = dev_trans_start(slave->dev);
                  if (bond_is_active_slave(slave) &&
                      (!time_in_range(jiffies,
                          trans_start - delta_in_ticks,
                          trans_start + 2 * delta_in_ticks + extra_ticks) ||
                       !time_in_range(jiffies,
                          slave_last_rx(bond, slave) - delta_in_ticks,
                          slave_last_rx(bond, slave) + 2 * delta_in_ticks + extra_ticks))) {
  
                          slave->new_link = BOND_LINK_DOWN;
                          commit++;
                  }
          }
  
          return commit;
  }
  
  /*
   * Called to commit link state changes noted by inspection step of
   * active-backup mode ARP monitor.
   *
   * Called with RTNL and bond->lock for read.
   */
  static void bond_ab_arp_commit(struct bonding *bond, int delta_in_ticks)
  {
          struct slave *slave;
          int i;
          unsigned long trans_start;
  
          bond_for_each_slave(bond, slave, i) {
                  switch (slave->new_link) {
                  case BOND_LINK_NOCHANGE:
                          continue;
  
                  case BOND_LINK_UP:
                          trans_start = dev_trans_start(slave->dev);
                          if ((!bond->curr_active_slave &&
                               time_in_range(jiffies,
                                             trans_start - delta_in_ticks,
                                             trans_start + delta_in_ticks + delta_in_ticks / 2)) ||
                              bond->curr_active_slave != slave) {
                                  slave->link = BOND_LINK_UP;
                                  if (bond->current_arp_slave) {
                                          bond_set_slave_inactive_flags(
                                                  bond->current_arp_slave);
                                          bond->current_arp_slave = NULL;
                                  }
  
                                  pr_info("%s: link status definitely up for interface %s.\n",
                                          bond->dev->name, slave->dev->name);
  
                                  if (!bond->curr_active_slave ||
                                      (slave == bond->primary_slave))
                                          goto do_failover;
  
                          }
  
                          continue;
  
                  case BOND_LINK_DOWN:
                          if (slave->link_failure_count < UINT_MAX)
                                  slave->link_failure_count++;
  
                          slave->link = BOND_LINK_DOWN;
                          bond_set_slave_inactive_flags(slave);
  
                          pr_info("%s: link status definitely down for interface %s, disabling it\n",
                                  bond->dev->name, slave->dev->name);
  
                          if (slave == bond->curr_active_slave) {
                                  bond->current_arp_slave = NULL;
                                  goto do_failover;
                          }
  
                          continue;
  
                  default:
                          pr_err("%s: impossible: new_link %d on slave %s\n",
                                 bond->dev->name, slave->new_link,
                                 slave->dev->name);
                          continue;
                  }
  
  do_failover:
                  ASSERT_RTNL();
                  block_netpoll_tx();
                  write_lock_bh(&bond->curr_slave_lock);
                  bond_select_active_slave(bond);
                  write_unlock_bh(&bond->curr_slave_lock);
                  unblock_netpoll_tx();
          }
  
          bond_set_carrier(bond);
  }
  
  /*
   * Send ARP probes for active-backup mode ARP monitor.
   *
   * Called with bond->lock held for read.
   */
  static void bond_ab_arp_probe(struct bonding *bond)
  {
          struct slave *slave;
          int i;
  
          read_lock(&bond->curr_slave_lock);
  
          if (bond->current_arp_slave && bond->curr_active_slave)
                  pr_info("PROBE: c_arp %s && cas %s BAD\n",
                          bond->current_arp_slave->dev->name,
                          bond->curr_active_slave->dev->name);
  
          if (bond->curr_active_slave) {
                  bond_arp_send_all(bond, bond->curr_active_slave);
                  read_unlock(&bond->curr_slave_lock);
                  return;
          }
  
          read_unlock(&bond->curr_slave_lock);
  
          /* if we don't have a curr_active_slave, search for the next available
           * backup slave from the current_arp_slave and make it the candidate
           * for becoming the curr_active_slave
           */
  
          if (!bond->current_arp_slave) {
                  bond->current_arp_slave = bond->first_slave;
                  if (!bond->current_arp_slave)
                          return;
          }
  
          bond_set_slave_inactive_flags(bond->current_arp_slave);
  
          /* search for next candidate */
          bond_for_each_slave_from(bond, slave, i, bond->current_arp_slave->next) {
                  if (IS_UP(slave->dev)) {
                          slave->link = BOND_LINK_BACK;
                          bond_set_slave_active_flags(slave);
                          bond_arp_send_all(bond, slave);
                          slave->jiffies = jiffies;
                          bond->current_arp_slave = slave;
                          break;
                  }
  
                  /* if the link state is up at this point, we
                   * mark it down - this can happen if we have
                   * simultaneous link failures and
                   * reselect_active_interface doesn't make this
                   * one the current slave so it is still marked
                   * up when it is actually down
                   */
                  if (slave->link == BOND_LINK_UP) {
                          slave->link = BOND_LINK_DOWN;
                          if (slave->link_failure_count < UINT_MAX)
                                  slave->link_failure_count++;
  
                          bond_set_slave_inactive_flags(slave);
  
                          pr_info("%s: backup interface %s is now down.\n",
                                  bond->dev->name, slave->dev->name);
                  }
          }
  }
  
  void bond_activebackup_arp_mon(struct work_struct *work)
  {
          struct bonding *bond = container_of(work, struct bonding,
                                              arp_work.work);
          bool should_notify_peers = false;
          int delta_in_ticks;
  
          read_lock(&bond->lock);
  
          delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
  
          if (bond->slave_cnt == 0)
                  goto re_arm;
  
          should_notify_peers = bond_should_notify_peers(bond);
  
          if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
                  read_unlock(&bond->lock);
  
                  /* Race avoidance with bond_close flush of workqueue */
                  if (!rtnl_trylock()) {
                          read_lock(&bond->lock);
                          delta_in_ticks = 1;
                          should_notify_peers = false;
                          goto re_arm;
                  }
  
                  read_lock(&bond->lock);
  
                  bond_ab_arp_commit(bond, delta_in_ticks);
  
                  read_unlock(&bond->lock);
                  rtnl_unlock();
                  read_lock(&bond->lock);
          }
  
          bond_ab_arp_probe(bond);
  
  re_arm:
          if (bond->params.arp_interval)
                  queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
  
          read_unlock(&bond->lock);
  
          if (should_notify_peers) {
                  if (!rtnl_trylock()) {
                          read_lock(&bond->lock);
                          bond->send_peer_notif++;
                          read_unlock(&bond->lock);
                          return;
                  }
                  call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);
                  rtnl_unlock();
          }
  }
  
  /*-------------------------- netdev event handling --------------------------*/
  
  /*
   * Change device name
   */
  static int bond_event_changename(struct bonding *bond)
  {
          bond_remove_proc_entry(bond);
          bond_create_proc_entry(bond);
  
          bond_debug_reregister(bond);
  
          return NOTIFY_DONE;
  }
  
  static int bond_master_netdev_event(unsigned long event,
                                      struct net_device *bond_dev)
  {
          struct bonding *event_bond = netdev_priv(bond_dev);
  
          switch (event) {
          case NETDEV_CHANGENAME:
                  return bond_event_changename(event_bond);
          case NETDEV_UNREGISTER:
                  bond_remove_proc_entry(event_bond);
                  break;
          case NETDEV_REGISTER:
                  bond_create_proc_entry(event_bond);
                  break;
          default:
                  break;
          }
  
          return NOTIFY_DONE;
  }
  
  static int bond_slave_netdev_event(unsigned long event,
                                     struct net_device *slave_dev)
  {
          struct net_device *bond_dev = slave_dev->master;
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave = NULL;
  
          switch (event) {
          case NETDEV_UNREGISTER:
                  if (bond_dev) {
                          if (bond->setup_by_slave)
                                  bond_release_and_destroy(bond_dev, slave_dev);
                          else
                                  bond_release(bond_dev, slave_dev);
                  }
                  break;
          case NETDEV_UP:
          case NETDEV_CHANGE:
                  slave = bond_get_slave_by_dev(bond, slave_dev);
                  if (slave) {
                          u32 old_speed = slave->speed;
                          u8  old_duplex = slave->duplex;
  
                          bond_update_speed_duplex(slave);
  
                          if (bond->params.mode == BOND_MODE_8023AD) {
                                  if (old_speed != slave->speed)
                                          bond_3ad_adapter_speed_changed(slave);
                                  if (old_duplex != slave->duplex)
                                          bond_3ad_adapter_duplex_changed(slave);
                          }
                  }
  
                  break;
          case NETDEV_DOWN:
                  /*
                   * ... Or is it this?
                   */
                  break;
          case NETDEV_CHANGEMTU:
                  /*
                   * TODO: Should slaves be allowed to
                   * independently alter their MTU?  For
                   * an active-backup bond, slaves need
                   * not be the same type of device, so
                   * MTUs may vary.  For other modes,
                   * slaves arguably should have the
                   * same MTUs. To do this, we'd need to
                   * take over the slave's change_mtu
                   * function for the duration of their
                   * servitude.
                   */
                  break;
          case NETDEV_CHANGENAME:
                  /*
                   * TODO: handle changing the primary's name
                   */
                  break;
          case NETDEV_FEAT_CHANGE:
                  bond_compute_features(bond);
                  break;
          default:
                  break;
          }
  
          return NOTIFY_DONE;
  }
  
  /*
   * bond_netdev_event: handle netdev notifier chain events.
   *
   * This function receives events for the netdev chain.  The caller (an
   * ioctl handler calling blocking_notifier_call_chain) holds the necessary
   * locks for us to safely manipulate the slave devices (RTNL lock,
   * dev_probe_lock).
   */
  static int bond_netdev_event(struct notifier_block *this,
                               unsigned long event, void *ptr)
  {
          struct net_device *event_dev = (struct net_device *)ptr;
  
          pr_debug("event_dev: %s, event: %lx\n",
                   event_dev ? event_dev->name : "None",
                   event);
  
          if (!(event_dev->priv_flags & IFF_BONDING))
                  return NOTIFY_DONE;
  
          if (event_dev->flags & IFF_MASTER) {
                  pr_debug("IFF_MASTER\n");
                  return bond_master_netdev_event(event, event_dev);
          }
  
          if (event_dev->flags & IFF_SLAVE) {
                  pr_debug("IFF_SLAVE\n");
                  return bond_slave_netdev_event(event, event_dev);
          }
  
          return NOTIFY_DONE;
  }
  
  static struct notifier_block bond_netdev_notifier = {
          .notifier_call = bond_netdev_event,
  };
  
  /*---------------------------- Hashing Policies -----------------------------*/
  
  /*
   * Hash for the output device based upon layer 2 data
   */
  static int bond_xmit_hash_policy_l2(struct sk_buff *skb, int count)
  {
          struct ethhdr *data = (struct ethhdr *)skb->data;
  
          if (skb_headlen(skb) >= offsetof(struct ethhdr, h_proto))
                  return (data->h_dest[5] ^ data->h_source[5]) % count;
  
          return 0;
  }
  
  /*
   * Hash for the output device based upon layer 2 and layer 3 data. If
   * the packet is not IP, fall back on bond_xmit_hash_policy_l2()
   */
  static int bond_xmit_hash_policy_l23(struct sk_buff *skb, int count)
  {
          struct ethhdr *data = (struct ethhdr *)skb->data;
          struct iphdr *iph;
          struct ipv6hdr *ipv6h;
          u32 v6hash;
          __be32 *s, *d;
  
          if (skb->protocol == htons(ETH_P_IP) &&
              skb_network_header_len(skb) >= sizeof(*iph)) {
                  iph = ip_hdr(skb);
                  return ((ntohl(iph->saddr ^ iph->daddr) & 0xffff) ^
                          (data->h_dest[5] ^ data->h_source[5])) % count;
          } else if (skb->protocol == htons(ETH_P_IPV6) &&
                     skb_network_header_len(skb) >= sizeof(*ipv6h)) {
                  ipv6h = ipv6_hdr(skb);
                  s = &ipv6h->saddr.s6_addr32[0];
                  d = &ipv6h->daddr.s6_addr32[0];
                  v6hash = (s[1] ^ d[1]) ^ (s[2] ^ d[2]) ^ (s[3] ^ d[3]);
                  v6hash ^= (v6hash >> 24) ^ (v6hash >> 16) ^ (v6hash >> 8);
                  return (v6hash ^ data->h_dest[5] ^ data->h_source[5]) % count;
          }
  
          return bond_xmit_hash_policy_l2(skb, count);
  }
  
  /*
   * Hash for the output device based upon layer 3 and layer 4 data. If
   * the packet is a frag or not TCP or UDP, just use layer 3 data.  If it is
   * altogether not IP, fall back on bond_xmit_hash_policy_l2()
   */
  static int bond_xmit_hash_policy_l34(struct sk_buff *skb, int count)
  {
          u32 layer4_xor = 0;
          struct iphdr *iph;
          struct ipv6hdr *ipv6h;
          __be32 *s, *d;
          __be16 *layer4hdr;
  
          if (skb->protocol == htons(ETH_P_IP) &&
              skb_network_header_len(skb) >= sizeof(*iph)) {
                  iph = ip_hdr(skb);
                  if (!ip_is_fragment(iph) &&
                      (iph->protocol == IPPROTO_TCP ||
                       iph->protocol == IPPROTO_UDP) &&
                      (skb_headlen(skb) - skb_network_offset(skb) >=
                       iph->ihl * sizeof(u32) + sizeof(*layer4hdr) * 2)) {
                          layer4hdr = (__be16 *)((u32 *)iph + iph->ihl);
                          layer4_xor = ntohs(*layer4hdr ^ *(layer4hdr + 1));
                  }
                  return (layer4_xor ^
                          ((ntohl(iph->saddr ^ iph->daddr)) & 0xffff)) % count;
          } else if (skb->protocol == htons(ETH_P_IPV6) &&
                     skb_network_header_len(skb) >= sizeof(*ipv6h)) {
                  ipv6h = ipv6_hdr(skb);
                  if ((ipv6h->nexthdr == IPPROTO_TCP ||
                       ipv6h->nexthdr == IPPROTO_UDP) &&
                      (skb_headlen(skb) - skb_network_offset(skb) >=
                       sizeof(*ipv6h) + sizeof(*layer4hdr) * 2)) {
                          layer4hdr = (__be16 *)(ipv6h + 1);
                          layer4_xor = ntohs(*layer4hdr ^ *(layer4hdr + 1));
                  }
                  s = &ipv6h->saddr.s6_addr32[0];
                  d = &ipv6h->daddr.s6_addr32[0];
                  layer4_xor ^= (s[1] ^ d[1]) ^ (s[2] ^ d[2]) ^ (s[3] ^ d[3]);
                  layer4_xor ^= (layer4_xor >> 24) ^ (layer4_xor >> 16) ^
                                 (layer4_xor >> 8);
                  return layer4_xor % count;
          }
  
          return bond_xmit_hash_policy_l2(skb, count);
  }
  
  /*-------------------------- Device entry points ----------------------------*/
  
  static void bond_work_init_all(struct bonding *bond)
  {
          INIT_DELAYED_WORK(&bond->mcast_work,
                            bond_resend_igmp_join_requests_delayed);
          INIT_DELAYED_WORK(&bond->alb_work, bond_alb_monitor);
          INIT_DELAYED_WORK(&bond->mii_work, bond_mii_monitor);
          if (bond->params.mode == BOND_MODE_ACTIVEBACKUP)
                  INIT_DELAYED_WORK(&bond->arp_work, bond_activebackup_arp_mon);
          else
                  INIT_DELAYED_WORK(&bond->arp_work, bond_loadbalance_arp_mon);
          INIT_DELAYED_WORK(&bond->ad_work, bond_3ad_state_machine_handler);
  }
  
  static void bond_work_cancel_all(struct bonding *bond)
  {
          cancel_delayed_work_sync(&bond->mii_work);
          cancel_delayed_work_sync(&bond->arp_work);
          cancel_delayed_work_sync(&bond->alb_work);
          cancel_delayed_work_sync(&bond->ad_work);
          cancel_delayed_work_sync(&bond->mcast_work);
  }
  
  static int bond_open(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave;
          int i;
  
          /* reset slave->backup and slave->inactive */
          read_lock(&bond->lock);
          if (bond->slave_cnt > 0) {
                  read_lock(&bond->curr_slave_lock);
                  bond_for_each_slave(bond, slave, i) {
                          if ((bond->params.mode == BOND_MODE_ACTIVEBACKUP)
                                  && (slave != bond->curr_active_slave)) {
                                  bond_set_slave_inactive_flags(slave);
                          } else {
                                  bond_set_slave_active_flags(slave);
                          }
                  }
                  read_unlock(&bond->curr_slave_lock);
          }
          read_unlock(&bond->lock);
  
          bond_work_init_all(bond);
  
          if (bond_is_lb(bond)) {
                  /* bond_alb_initialize must be called before the timer
                   * is started.
                   */
                  if (bond_alb_initialize(bond, (bond->params.mode == BOND_MODE_ALB)))
                          return -ENOMEM;
                  queue_delayed_work(bond->wq, &bond->alb_work, 0);
          }
  
          if (bond->params.miimon)  /* link check interval, in milliseconds. */
                  queue_delayed_work(bond->wq, &bond->mii_work, 0);
  
          if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
                  queue_delayed_work(bond->wq, &bond->arp_work, 0);
                  if (bond->params.arp_validate)
                          bond->recv_probe = bond_arp_rcv;
          }
  
          if (bond->params.mode == BOND_MODE_8023AD) {
                  queue_delayed_work(bond->wq, &bond->ad_work, 0);
                  /* register to receive LACPDUs */
                  bond->recv_probe = bond_3ad_lacpdu_recv;
                  bond_3ad_initiate_agg_selection(bond, 1);
          }
  
          return 0;
  }
  
  static int bond_close(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
  
          write_lock_bh(&bond->lock);
          bond->send_peer_notif = 0;
          write_unlock_bh(&bond->lock);
  
          bond_work_cancel_all(bond);
          if (bond_is_lb(bond)) {
                  /* Must be called only after all
                   * slaves have been released
                   */
                  bond_alb_deinitialize(bond);
          }
          bond->recv_probe = NULL;
  
          return 0;
  }
  
  static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev,
                                                  struct rtnl_link_stats64 *stats)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct rtnl_link_stats64 temp;
          struct slave *slave;
          int i;
  
          memset(stats, 0, sizeof(*stats));
  
          read_lock_bh(&bond->lock);
  
          bond_for_each_slave(bond, slave, i) {
                  const struct rtnl_link_stats64 *sstats =
                          dev_get_stats(slave->dev, &temp);
  
                  stats->rx_packets += sstats->rx_packets;
                  stats->rx_bytes += sstats->rx_bytes;
                  stats->rx_errors += sstats->rx_errors;
                  stats->rx_dropped += sstats->rx_dropped;
  
                  stats->tx_packets += sstats->tx_packets;
                  stats->tx_bytes += sstats->tx_bytes;
                  stats->tx_errors += sstats->tx_errors;
                  stats->tx_dropped += sstats->tx_dropped;
  
                  stats->multicast += sstats->multicast;
                  stats->collisions += sstats->collisions;
  
                  stats->rx_length_errors += sstats->rx_length_errors;
                  stats->rx_over_errors += sstats->rx_over_errors;
                  stats->rx_crc_errors += sstats->rx_crc_errors;
                  stats->rx_frame_errors += sstats->rx_frame_errors;
                  stats->rx_fifo_errors += sstats->rx_fifo_errors;
                  stats->rx_missed_errors += sstats->rx_missed_errors;
  
                  stats->tx_aborted_errors += sstats->tx_aborted_errors;
                  stats->tx_carrier_errors += sstats->tx_carrier_errors;
                  stats->tx_fifo_errors += sstats->tx_fifo_errors;
                  stats->tx_heartbeat_errors += sstats->tx_heartbeat_errors;
                  stats->tx_window_errors += sstats->tx_window_errors;
          }
  
          read_unlock_bh(&bond->lock);
  
          return stats;
  }
  
  static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd)
  {
          struct net_device *slave_dev = NULL;
          struct ifbond k_binfo;
          struct ifbond __user *u_binfo = NULL;
          struct ifslave k_sinfo;
          struct ifslave __user *u_sinfo = NULL;
          struct mii_ioctl_data *mii = NULL;
          int res = 0;
  
          pr_debug("bond_ioctl: master=%s, cmd=%d\n", bond_dev->name, cmd);
  
          switch (cmd) {
          case SIOCGMIIPHY:
                  mii = if_mii(ifr);
                  if (!mii)
                          return -EINVAL;
  
                  mii->phy_id = 0;
                  /* Fall Through */
          case SIOCGMIIREG:
                  /*
                   * We do this again just in case we were called by SIOCGMIIREG
                   * instead of SIOCGMIIPHY.
                   */
                  mii = if_mii(ifr);
                  if (!mii)
                          return -EINVAL;
  
  
                  if (mii->reg_num == 1) {
                          struct bonding *bond = netdev_priv(bond_dev);
                          mii->val_out = 0;
                          read_lock(&bond->lock);
                          read_lock(&bond->curr_slave_lock);
                          if (netif_carrier_ok(bond->dev))
                                  mii->val_out = BMSR_LSTATUS;
  
                          read_unlock(&bond->curr_slave_lock);
                          read_unlock(&bond->lock);
                  }
  
                  return 0;
          case BOND_INFO_QUERY_OLD:
          case SIOCBONDINFOQUERY:
                  u_binfo = (struct ifbond __user *)ifr->ifr_data;
  
                  if (copy_from_user(&k_binfo, u_binfo, sizeof(ifbond)))
                          return -EFAULT;
  
                  res = bond_info_query(bond_dev, &k_binfo);
                  if (res == 0 &&
                      copy_to_user(u_binfo, &k_binfo, sizeof(ifbond)))
                          return -EFAULT;
  
                  return res;
          case BOND_SLAVE_INFO_QUERY_OLD:
          case SIOCBONDSLAVEINFOQUERY:
                  u_sinfo = (struct ifslave __user *)ifr->ifr_data;
  
                  if (copy_from_user(&k_sinfo, u_sinfo, sizeof(ifslave)))
                          return -EFAULT;
  
                  res = bond_slave_info_query(bond_dev, &k_sinfo);
                  if (res == 0 &&
                      copy_to_user(u_sinfo, &k_sinfo, sizeof(ifslave)))
                          return -EFAULT;
  
                  return res;
          default:
                  /* Go on */
                  break;
          }
  
          if (!capable(CAP_NET_ADMIN))
                  return -EPERM;
  
          slave_dev = dev_get_by_name(dev_net(bond_dev), ifr->ifr_slave);
  
          pr_debug("slave_dev=%p:\n", slave_dev);
  
          if (!slave_dev)
                  res = -ENODEV;
          else {
                  pr_debug("slave_dev->name=%s:\n", slave_dev->name);
                  switch (cmd) {
                  case BOND_ENSLAVE_OLD:
                  case SIOCBONDENSLAVE:
                          res = bond_enslave(bond_dev, slave_dev);
                          break;
                  case BOND_RELEASE_OLD:
                  case SIOCBONDRELEASE:
                          res = bond_release(bond_dev, slave_dev);
                          break;
                  case BOND_SETHWADDR_OLD:
                  case SIOCBONDSETHWADDR:
                          res = bond_sethwaddr(bond_dev, slave_dev);
                          break;
                  case BOND_CHANGE_ACTIVE_OLD:
                  case SIOCBONDCHANGEACTIVE:
                          res = bond_ioctl_change_active(bond_dev, slave_dev);
                          break;
                  default:
                          res = -EOPNOTSUPP;
                  }
  
                  dev_put(slave_dev);
          }
  
          return res;
  }
  
  static bool bond_addr_in_mc_list(unsigned char *addr,
                                   struct netdev_hw_addr_list *list,
                                   int addrlen)
  {
          struct netdev_hw_addr *ha;
  
          netdev_hw_addr_list_for_each(ha, list)
                  if (!memcmp(ha->addr, addr, addrlen))
                          return true;
  
          return false;
  }
  
  static void bond_change_rx_flags(struct net_device *bond_dev, int change)
  {
          struct bonding *bond = netdev_priv(bond_dev);
  
          if (change & IFF_PROMISC)
                  bond_set_promiscuity(bond,
                                       bond_dev->flags & IFF_PROMISC ? 1 : -1);
  
          if (change & IFF_ALLMULTI)
                  bond_set_allmulti(bond,
                                    bond_dev->flags & IFF_ALLMULTI ? 1 : -1);
  }
  
  static void bond_set_multicast_list(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct netdev_hw_addr *ha;
          bool found;
  
          read_lock(&bond->lock);
  
          /* looking for addresses to add to slaves' mc list */
          netdev_for_each_mc_addr(ha, bond_dev) {
                  found = bond_addr_in_mc_list(ha->addr, &bond->mc_list,
                                               bond_dev->addr_len);
                  if (!found)
                          bond_mc_add(bond, ha->addr);
          }
  
          /* looking for addresses to delete from slaves' list */
          netdev_hw_addr_list_for_each(ha, &bond->mc_list) {
                  found = bond_addr_in_mc_list(ha->addr, &bond_dev->mc,
                                               bond_dev->addr_len);
                  if (!found)
                          bond_mc_del(bond, ha->addr);
          }
  
          /* save master's multicast list */
          __hw_addr_flush(&bond->mc_list);
          __hw_addr_add_multiple(&bond->mc_list, &bond_dev->mc,
                                 bond_dev->addr_len, NETDEV_HW_ADDR_T_MULTICAST);
  
          read_unlock(&bond->lock);
  }
  
  static int bond_neigh_init(struct neighbour *n)
  {
          struct bonding *bond = netdev_priv(n->dev);
          struct slave *slave = bond->first_slave;
          const struct net_device_ops *slave_ops;
          struct neigh_parms parms;
          int ret;
  
          if (!slave)
                  return 0;
  
          slave_ops = slave->dev->netdev_ops;
  
          if (!slave_ops->ndo_neigh_setup)
                  return 0;
  
          parms.neigh_setup = NULL;
          parms.neigh_cleanup = NULL;
          ret = slave_ops->ndo_neigh_setup(slave->dev, &parms);
          if (ret)
                  return ret;
  
          /*
           * Assign slave's neigh_cleanup to neighbour in case cleanup is called
           * after the last slave has been detached.  Assumes that all slaves
           * utilize the same neigh_cleanup (true at this writing as only user
           * is ipoib).
           */
          n->parms->neigh_cleanup = parms.neigh_cleanup;
  
          if (!parms.neigh_setup)
                  return 0;
  
          return parms.neigh_setup(n);
  }
  
  /*
   * The bonding ndo_neigh_setup is called at init time beofre any
   * slave exists. So we must declare proxy setup function which will
   * be used at run time to resolve the actual slave neigh param setup.
   */
  static int bond_neigh_setup(struct net_device *dev,
                              struct neigh_parms *parms)
  {
          parms->neigh_setup   = bond_neigh_init;
  
          return 0;
  }
  
  /*
   * Change the MTU of all of a master's slaves to match the master
   */
  static int bond_change_mtu(struct net_device *bond_dev, int new_mtu)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave, *stop_at;
          int res = 0;
          int i;
  
          pr_debug("bond=%p, name=%s, new_mtu=%d\n", bond,
                   (bond_dev ? bond_dev->name : "None"), new_mtu);
  
          /* Can't hold bond->lock with bh disabled here since
           * some base drivers panic. On the other hand we can't
           * hold bond->lock without bh disabled because we'll
           * deadlock. The only solution is to rely on the fact
           * that we're under rtnl_lock here, and the slaves
           * list won't change. This doesn't solve the problem
           * of setting the slave's MTU while it is
           * transmitting, but the assumption is that the base
           * driver can handle that.
           *
           * TODO: figure out a way to safely iterate the slaves
           * list, but without holding a lock around the actual
           * call to the base driver.
           */
  
          bond_for_each_slave(bond, slave, i) {
                  pr_debug("s %p s->p %p c_m %p\n",
                           slave,
                           slave->prev,
                           slave->dev->netdev_ops->ndo_change_mtu);
  
                  res = dev_set_mtu(slave->dev, new_mtu);
  
                  if (res) {
                          /* If we failed to set the slave's mtu to the new value
                           * we must abort the operation even in ACTIVE_BACKUP
                           * mode, because if we allow the backup slaves to have
                           * different mtu values than the active slave we'll
                           * need to change their mtu when doing a failover. That
                           * means changing their mtu from timer context, which
                           * is probably not a good idea.
                           */
                          pr_debug("err %d %s\n", res, slave->dev->name);
                          goto unwind;
                  }
          }
  
          bond_dev->mtu = new_mtu;
  
          return 0;
  
  unwind:
          /* unwind from head to the slave that failed */
          stop_at = slave;
          bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
                  int tmp_res;
  
                  tmp_res = dev_set_mtu(slave->dev, bond_dev->mtu);
                  if (tmp_res) {
                          pr_debug("unwind err %d dev %s\n",
                                   tmp_res, slave->dev->name);
                  }
          }
  
          return res;
  }
  
  /*
   * Change HW address
   *
   * Note that many devices must be down to change the HW address, and
   * downing the master releases all slaves.  We can make bonds full of
   * bonding devices to test this, however.
   */
  static int bond_set_mac_address(struct net_device *bond_dev, void *addr)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct sockaddr *sa = addr, tmp_sa;
          struct slave *slave, *stop_at;
          int res = 0;
          int i;
  
          if (bond->params.mode == BOND_MODE_ALB)
                  return bond_alb_set_mac_address(bond_dev, addr);
  
  
          pr_debug("bond=%p, name=%s\n",
                   bond, bond_dev ? bond_dev->name : "None");
  
          /*
           * If fail_over_mac is set to active, do nothing and return
           * success.  Returning an error causes ifenslave to fail.
           */
          if (bond->params.fail_over_mac == BOND_FOM_ACTIVE)
                  return 0;
  
          if (!is_valid_ether_addr(sa->sa_data))
                  return -EADDRNOTAVAIL;
  
          /* Can't hold bond->lock with bh disabled here since
           * some base drivers panic. On the other hand we can't
           * hold bond->lock without bh disabled because we'll
           * deadlock. The only solution is to rely on the fact
           * that we're under rtnl_lock here, and the slaves
           * list won't change. This doesn't solve the problem
           * of setting the slave's hw address while it is
           * transmitting, but the assumption is that the base
           * driver can handle that.
           *
           * TODO: figure out a way to safely iterate the slaves
           * list, but without holding a lock around the actual
           * call to the base driver.
           */
  
          bond_for_each_slave(bond, slave, i) {
                  const struct net_device_ops *slave_ops = slave->dev->netdev_ops;
                  pr_debug("slave %p %s\n", slave, slave->dev->name);
  
                  if (slave_ops->ndo_set_mac_address == NULL) {
                          res = -EOPNOTSUPP;
                          pr_debug("EOPNOTSUPP %s\n", slave->dev->name);
                          goto unwind;
                  }
  
                  res = dev_set_mac_address(slave->dev, addr);
                  if (res) {
                          /* TODO: consider downing the slave
                           * and retry ?
                           * User should expect communications
                           * breakage anyway until ARP finish
                           * updating, so...
                           */
                          pr_debug("err %d %s\n", res, slave->dev->name);
                          goto unwind;
                  }
          }
  
          /* success */
          memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
          return 0;
  
  unwind:
          memcpy(tmp_sa.sa_data, bond_dev->dev_addr, bond_dev->addr_len);
          tmp_sa.sa_family = bond_dev->type;
  
          /* unwind from head to the slave that failed */
          stop_at = slave;
          bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
                  int tmp_res;
  
                  tmp_res = dev_set_mac_address(slave->dev, &tmp_sa);
                  if (tmp_res) {
                          pr_debug("unwind err %d dev %s\n",
                                   tmp_res, slave->dev->name);
                  }
          }
  
          return res;
  }
  
  static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave, *start_at;
          int i, slave_no, res = 1;
          struct iphdr *iph = ip_hdr(skb);
  
          /*
           * Start with the curr_active_slave that joined the bond as the
           * default for sending IGMP traffic.  For failover purposes one
           * needs to maintain some consistency for the interface that will
           * send the join/membership reports.  The curr_active_slave found
           * will send all of this type of traffic.
           */
          if ((iph->protocol == IPPROTO_IGMP) &&
              (skb->protocol == htons(ETH_P_IP))) {
  
                  read_lock(&bond->curr_slave_lock);
                  slave = bond->curr_active_slave;
                  read_unlock(&bond->curr_slave_lock);
  
                  if (!slave)
                          goto out;
          } else {
                  /*
                   * Concurrent TX may collide on rr_tx_counter; we accept
                   * that as being rare enough not to justify using an
                   * atomic op here.
                   */
                  slave_no = bond->rr_tx_counter++ % bond->slave_cnt;
  
                  bond_for_each_slave(bond, slave, i) {
                          slave_no--;
                          if (slave_no < 0)
                                  break;
                  }
          }
  
          start_at = slave;
          bond_for_each_slave_from(bond, slave, i, start_at) {
                  if (IS_UP(slave->dev) &&
                      (slave->link == BOND_LINK_UP) &&
                      bond_is_active_slave(slave)) {
                          res = bond_dev_queue_xmit(bond, skb, slave->dev);
                          break;
                  }
          }
  
  out:
          if (res) {
                  /* no suitable interface, frame not sent */
                  kfree_skb(skb);
          }
  
          return NETDEV_TX_OK;
  }
  
  
  /*
   * in active-backup mode, we know that bond->curr_active_slave is always valid if
   * the bond has a usable interface.
   */
  static int bond_xmit_activebackup(struct sk_buff *skb, struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          int res = 1;
  
          read_lock(&bond->curr_slave_lock);
  
          if (bond->curr_active_slave)
                  res = bond_dev_queue_xmit(bond, skb,
                          bond->curr_active_slave->dev);
  
          read_unlock(&bond->curr_slave_lock);
  
          if (res)
                  /* no suitable interface, frame not sent */
                  kfree_skb(skb);
  
          return NETDEV_TX_OK;
  }
  
  /*
   * In bond_xmit_xor() , we determine the output device by using a pre-
   * determined xmit_hash_policy(), If the selected device is not enabled,
   * find the next active slave.
   */
  static int bond_xmit_xor(struct sk_buff *skb, struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave, *start_at;
          int slave_no;
          int i;
          int res = 1;
  
          slave_no = bond->xmit_hash_policy(skb, bond->slave_cnt);
  
          bond_for_each_slave(bond, slave, i) {
                  slave_no--;
                  if (slave_no < 0)
                          break;
          }
  
          start_at = slave;
  
          bond_for_each_slave_from(bond, slave, i, start_at) {
                  if (IS_UP(slave->dev) &&
                      (slave->link == BOND_LINK_UP) &&
                      bond_is_active_slave(slave)) {
                          res = bond_dev_queue_xmit(bond, skb, slave->dev);
                          break;
                  }
          }
  
          if (res) {
                  /* no suitable interface, frame not sent */
                  kfree_skb(skb);
          }
  
          return NETDEV_TX_OK;
  }
  
  /*
   * in broadcast mode, we send everything to all usable interfaces.
   */
  static int bond_xmit_broadcast(struct sk_buff *skb, struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct slave *slave, *start_at;
          struct net_device *tx_dev = NULL;
          int i;
          int res = 1;
  
          read_lock(&bond->curr_slave_lock);
          start_at = bond->curr_active_slave;
          read_unlock(&bond->curr_slave_lock);
  
          if (!start_at)
                  goto out;
  
          bond_for_each_slave_from(bond, slave, i, start_at) {
                  if (IS_UP(slave->dev) &&
                      (slave->link == BOND_LINK_UP) &&
                      bond_is_active_slave(slave)) {
                          if (tx_dev) {
                                  struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
                                  if (!skb2) {
                                          pr_err("%s: Error: bond_xmit_broadcast(): skb_clone() failed\n",
                                                 bond_dev->name);
                                          continue;
                                  }
  
                                  res = bond_dev_queue_xmit(bond, skb2, tx_dev);
                                  if (res) {
                                          kfree_skb(skb2);
                                          continue;
                                  }
                          }
                          tx_dev = slave->dev;
                  }
          }
  
          if (tx_dev)
                  res = bond_dev_queue_xmit(bond, skb, tx_dev);
  
  out:
          if (res)
                  /* no suitable interface, frame not sent */
                  kfree_skb(skb);
  
          /* frame sent to all suitable interfaces */
          return NETDEV_TX_OK;
  }
  
  /*------------------------- Device initialization ---------------------------*/
  
  static void bond_set_xmit_hash_policy(struct bonding *bond)
  {
          switch (bond->params.xmit_policy) {
          case BOND_XMIT_POLICY_LAYER23:
                  bond->xmit_hash_policy = bond_xmit_hash_policy_l23;
                  break;
          case BOND_XMIT_POLICY_LAYER34:
                  bond->xmit_hash_policy = bond_xmit_hash_policy_l34;
                  break;
          case BOND_XMIT_POLICY_LAYER2:
          default:
                  bond->xmit_hash_policy = bond_xmit_hash_policy_l2;
                  break;
          }
  }
  
  /*
   * Lookup the slave that corresponds to a qid
   */
  static inline int bond_slave_override(struct bonding *bond,
                                        struct sk_buff *skb)
  {
          int i, res = 1;
          struct slave *slave = NULL;
          struct slave *check_slave;
  
          if (!skb->queue_mapping)
                  return 1;
  
          /* Find out if any slaves have the same mapping as this skb. */
          bond_for_each_slave(bond, check_slave, i) {
                  if (check_slave->queue_id == skb->queue_mapping) {
                          slave = check_slave;
                          break;
                  }
          }
  
          /* If the slave isn't UP, use default transmit policy. */
          if (slave && slave->queue_id && IS_UP(slave->dev) &&
              (slave->link == BOND_LINK_UP)) {
                  res = bond_dev_queue_xmit(bond, skb, slave->dev);
          }
  
          return res;
  }
  
  
  static u16 bond_select_queue(struct net_device *dev, struct sk_buff *skb)
  {
          /*
           * This helper function exists to help dev_pick_tx get the correct
           * destination queue.  Using a helper function skips a call to
           * skb_tx_hash and will put the skbs in the queue we expect on their
           * way down to the bonding driver.
           */
          u16 txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0;
  
          /*
           * Save the original txq to restore before passing to the driver
           */
          qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping;
  
          if (unlikely(txq >= dev->real_num_tx_queues)) {
                  do {
                          txq -= dev->real_num_tx_queues;
                  } while (txq >= dev->real_num_tx_queues);
          }
          return txq;
  }
  
  static netdev_tx_t __bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
  {
          struct bonding *bond = netdev_priv(dev);
  
          if (TX_QUEUE_OVERRIDE(bond->params.mode)) {
                  if (!bond_slave_override(bond, skb))
                          return NETDEV_TX_OK;
          }
  
          switch (bond->params.mode) {
          case BOND_MODE_ROUNDROBIN:
                  return bond_xmit_roundrobin(skb, dev);
          case BOND_MODE_ACTIVEBACKUP:
                  return bond_xmit_activebackup(skb, dev);
          case BOND_MODE_XOR:
                  return bond_xmit_xor(skb, dev);
          case BOND_MODE_BROADCAST:
                  return bond_xmit_broadcast(skb, dev);
          case BOND_MODE_8023AD:
                  return bond_3ad_xmit_xor(skb, dev);
          case BOND_MODE_ALB:
          case BOND_MODE_TLB:
                  return bond_alb_xmit(skb, dev);
          default:
                  /* Should never happen, mode already checked */
                  pr_err("%s: Error: Unknown bonding mode %d\n",
                         dev->name, bond->params.mode);
                  WARN_ON_ONCE(1);
                  kfree_skb(skb);
                  return NETDEV_TX_OK;
          }
  }
  
  static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev)
  {
          struct bonding *bond = netdev_priv(dev);
          netdev_tx_t ret = NETDEV_TX_OK;
  
          /*
           * If we risk deadlock from transmitting this in the
           * netpoll path, tell netpoll to queue the frame for later tx
           */
          if (is_netpoll_tx_blocked(dev))
                  return NETDEV_TX_BUSY;
  
          read_lock(&bond->lock);
  
          if (bond->slave_cnt)
                  ret = __bond_start_xmit(skb, dev);
          else
                  kfree_skb(skb);
  
          read_unlock(&bond->lock);
  
          return ret;
  }
  
  /*
   * set bond mode specific net device operations
   */
  void bond_set_mode_ops(struct bonding *bond, int mode)
  {
          struct net_device *bond_dev = bond->dev;
  
          switch (mode) {
          case BOND_MODE_ROUNDROBIN:
                  break;
          case BOND_MODE_ACTIVEBACKUP:
                  break;
          case BOND_MODE_XOR:
                  bond_set_xmit_hash_policy(bond);
                  break;
          case BOND_MODE_BROADCAST:
                  break;
          case BOND_MODE_8023AD:
                  bond_set_xmit_hash_policy(bond);
                  break;
          case BOND_MODE_ALB:
                  /* FALLTHRU */
          case BOND_MODE_TLB:
                  break;
          default:
                  /* Should never happen, mode already checked */
                  pr_err("%s: Error: Unknown bonding mode %d\n",
                         bond_dev->name, mode);
                  break;
          }
  }
  
  static void bond_ethtool_get_drvinfo(struct net_device *bond_dev,
                                      struct ethtool_drvinfo *drvinfo)
  {
          strncpy(drvinfo->driver, DRV_NAME, 32);
          strncpy(drvinfo->version, DRV_VERSION, 32);
          snprintf(drvinfo->fw_version, 32, "%d", BOND_ABI_VERSION);
  }
  
  static const struct ethtool_ops bond_ethtool_ops = {
          .get_drvinfo            = bond_ethtool_get_drvinfo,
          .get_link               = ethtool_op_get_link,
  };
  
  static const struct net_device_ops bond_netdev_ops = {
          .ndo_init               = bond_init,
          .ndo_uninit             = bond_uninit,
          .ndo_open               = bond_open,
          .ndo_stop               = bond_close,
          .ndo_start_xmit         = bond_start_xmit,
          .ndo_select_queue       = bond_select_queue,
          .ndo_get_stats64        = bond_get_stats,
          .ndo_do_ioctl           = bond_do_ioctl,
          .ndo_change_rx_flags    = bond_change_rx_flags,
          .ndo_set_rx_mode        = bond_set_multicast_list,
          .ndo_change_mtu         = bond_change_mtu,
          .ndo_set_mac_address    = bond_set_mac_address,
          .ndo_neigh_setup        = bond_neigh_setup,
          .ndo_vlan_rx_add_vid    = bond_vlan_rx_add_vid,
          .ndo_vlan_rx_kill_vid   = bond_vlan_rx_kill_vid,
  #ifdef CONFIG_NET_POLL_CONTROLLER
          .ndo_netpoll_setup      = bond_netpoll_setup,
          .ndo_netpoll_cleanup    = bond_netpoll_cleanup,
          .ndo_poll_controller    = bond_poll_controller,
  #endif
          .ndo_add_slave          = bond_enslave,
          .ndo_del_slave          = bond_release,
          .ndo_fix_features       = bond_fix_features,
  };
  
  static void bond_destructor(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          if (bond->wq)
                  destroy_workqueue(bond->wq);
          free_netdev(bond_dev);
  }
  
  static void bond_setup(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
  
          /* initialize rwlocks */
          rwlock_init(&bond->lock);
          rwlock_init(&bond->curr_slave_lock);
  
          bond->params = bonding_defaults;
  
          /* Initialize pointers */
          bond->dev = bond_dev;
          INIT_LIST_HEAD(&bond->vlan_list);
  
          /* Initialize the device entry points */
          ether_setup(bond_dev);
          bond_dev->netdev_ops = &bond_netdev_ops;
          bond_dev->ethtool_ops = &bond_ethtool_ops;
          bond_set_mode_ops(bond, bond->params.mode);
  
          bond_dev->destructor = bond_destructor;
  
          /* Initialize the device options */
          bond_dev->tx_queue_len = 0;
          bond_dev->flags |= IFF_MASTER|IFF_MULTICAST;
          bond_dev->priv_flags |= IFF_BONDING;
          bond_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
  
          /* At first, we block adding VLANs. That's the only way to
           * prevent problems that occur when adding VLANs over an
           * empty bond. The block will be removed once non-challenged
           * slaves are enslaved.
           */
          bond_dev->features |= NETIF_F_VLAN_CHALLENGED;
  
          /* don't acquire bond device's netif_tx_lock when
           * transmitting */
          bond_dev->features |= NETIF_F_LLTX;
  
          /* By default, we declare the bond to be fully
           * VLAN hardware accelerated capable. Special
           * care is taken in the various xmit functions
           * when there are slaves that are not hw accel
           * capable
           */
  
          bond_dev->hw_features = BOND_VLAN_FEATURES |
                                  NETIF_F_HW_VLAN_TX |
                                  NETIF_F_HW_VLAN_RX |
                                  NETIF_F_HW_VLAN_FILTER;
  
          bond_dev->hw_features &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_HW_CSUM);
          bond_dev->features |= bond_dev->hw_features;
  }
  
  /*
  * Destroy a bonding device.
  * Must be under rtnl_lock when this function is called.
  */
  static void bond_uninit(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct vlan_entry *vlan, *tmp;
  
          bond_netpoll_cleanup(bond_dev);
  
          /* Release the bonded slaves */
          bond_release_all(bond_dev);
  
          list_del(&bond->bond_list);
  
          bond_debug_unregister(bond);
  
          __hw_addr_flush(&bond->mc_list);
  
          list_for_each_entry_safe(vlan, tmp, &bond->vlan_list, vlan_list) {
                  list_del(&vlan->vlan_list);
                  kfree(vlan);
          }
  }
  
  /*------------------------- Module initialization ---------------------------*/
  
  /*
   * Convert string input module parms.  Accept either the
   * number of the mode or its string name.  A bit complicated because
   * some mode names are substrings of other names, and calls from sysfs
   * may have whitespace in the name (trailing newlines, for example).
   */
  int bond_parse_parm(const char *buf, const struct bond_parm_tbl *tbl)
  {
          int modeint = -1, i, rv;
          char *p, modestr[BOND_MAX_MODENAME_LEN + 1] = { 0, };
  
          for (p = (char *)buf; *p; p++)
                  if (!(isdigit(*p) || isspace(*p)))
                          break;
  
          if (*p)
                  rv = sscanf(buf, "%20s", modestr);
          else
                  rv = sscanf(buf, "%d", &modeint);
  
          if (!rv)
                  return -1;
  
          for (i = 0; tbl[i].modename; i++) {
                  if (modeint == tbl[i].mode)
                          return tbl[i].mode;
                  if (strcmp(modestr, tbl[i].modename) == 0)
                          return tbl[i].mode;
          }
  
          return -1;
  }
  
  static int bond_check_params(struct bond_params *params)
  {
          int arp_validate_value, fail_over_mac_value, primary_reselect_value;
  
          /*
           * Convert string parameters.
           */
          if (mode) {
                  bond_mode = bond_parse_parm(mode, bond_mode_tbl);
                  if (bond_mode == -1) {
                          pr_err("Error: Invalid bonding mode \"%s\"\n",
                                 mode == NULL ? "NULL" : mode);
                          return -EINVAL;
                  }
          }
  
          if (xmit_hash_policy) {
                  if ((bond_mode != BOND_MODE_XOR) &&
                      (bond_mode != BOND_MODE_8023AD)) {
                          pr_info("xmit_hash_policy param is irrelevant in mode %s\n",
                                 bond_mode_name(bond_mode));
                  } else {
                          xmit_hashtype = bond_parse_parm(xmit_hash_policy,
                                                          xmit_hashtype_tbl);
                          if (xmit_hashtype == -1) {
                                  pr_err("Error: Invalid xmit_hash_policy \"%s\"\n",
                                         xmit_hash_policy == NULL ? "NULL" :
                                         xmit_hash_policy);
                                  return -EINVAL;
                          }
                  }
          }
  
          if (lacp_rate) {
                  if (bond_mode != BOND_MODE_8023AD) {
                          pr_info("lacp_rate param is irrelevant in mode %s\n",
                                  bond_mode_name(bond_mode));
                  } else {
                          lacp_fast = bond_parse_parm(lacp_rate, bond_lacp_tbl);
                          if (lacp_fast == -1) {
                                  pr_err("Error: Invalid lacp rate \"%s\"\n",
                                         lacp_rate == NULL ? "NULL" : lacp_rate);
                                  return -EINVAL;
                          }
                  }
          }
  
          if (ad_select) {
                  params->ad_select = bond_parse_parm(ad_select, ad_select_tbl);
                  if (params->ad_select == -1) {
                          pr_err("Error: Invalid ad_select \"%s\"\n",
                                 ad_select == NULL ? "NULL" : ad_select);
                          return -EINVAL;
                  }
  
                  if (bond_mode != BOND_MODE_8023AD) {
                          pr_warning("ad_select param only affects 802.3ad mode\n");
                  }
          } else {
                  params->ad_select = BOND_AD_STABLE;
          }
  
          if (max_bonds < 0) {
                  pr_warning("Warning: max_bonds (%d) not in range %d-%d, so it was reset to BOND_DEFAULT_MAX_BONDS (%d)\n",
                             max_bonds, 0, INT_MAX, BOND_DEFAULT_MAX_BONDS);
                  max_bonds = BOND_DEFAULT_MAX_BONDS;
          }
  
          if (miimon < 0) {
                  pr_warning("Warning: miimon module parameter (%d), not in range 0-%d, so it was reset to %d\n",
                             miimon, INT_MAX, BOND_LINK_MON_INTERV);
                  miimon = BOND_LINK_MON_INTERV;
          }
  
          if (updelay < 0) {
                  pr_warning("Warning: updelay module parameter (%d), not in range 0-%d, so it was reset to 0\n",
                             updelay, INT_MAX);
                  updelay = 0;
          }
  
          if (downdelay < 0) {
                  pr_warning("Warning: downdelay module parameter (%d), not in range 0-%d, so it was reset to 0\n",
                             downdelay, INT_MAX);
                  downdelay = 0;
          }
  
          if ((use_carrier != 0) && (use_carrier != 1)) {
                  pr_warning("Warning: use_carrier module parameter (%d), not of valid value (0/1), so it was set to 1\n",
                             use_carrier);
                  use_carrier = 1;
          }
  
          if (num_peer_notif < 0 || num_peer_notif > 255) {
                  pr_warning("Warning: num_grat_arp/num_unsol_na (%d) not in range 0-255 so it was reset to 1\n",
                             num_peer_notif);
                  num_peer_notif = 1;
          }
  
          /* reset values for 802.3ad */
          if (bond_mode == BOND_MODE_8023AD) {
                  if (!miimon) {
                          pr_warning("Warning: miimon must be specified, otherwise bonding will not detect link failure, speed and duplex which are essential for 802.3ad operation\n");
                          pr_warning("Forcing miimon to 100msec\n");
                          miimon = 100;
                  }
          }
  
          if (tx_queues < 1 || tx_queues > 255) {
                  pr_warning("Warning: tx_queues (%d) should be between "
                             "1 and 255, resetting to %d\n",
                             tx_queues, BOND_DEFAULT_TX_QUEUES);
                  tx_queues = BOND_DEFAULT_TX_QUEUES;
          }
  
          if ((all_slaves_active != 0) && (all_slaves_active != 1)) {
                  pr_warning("Warning: all_slaves_active module parameter (%d), "
                             "not of valid value (0/1), so it was set to "
                             "\n", all_slaves_active);
                  all_slaves_active = 0;
          }
  
          if (resend_igmp < 0 || resend_igmp > 255) {
                  pr_warning("Warning: resend_igmp (%d) should be between "
                             "0 and 255, resetting to %d\n",
                             resend_igmp, BOND_DEFAULT_RESEND_IGMP);
                  resend_igmp = BOND_DEFAULT_RESEND_IGMP;
          }
  
          /* reset values for TLB/ALB */
          if ((bond_mode == BOND_MODE_TLB) ||
              (bond_mode == BOND_MODE_ALB)) {
                  if (!miimon) {
                          pr_warning("Warning: miimon must be specified, otherwise bonding will not detect link failure and link speed which are essential for TLB/ALB load balancing\n");
                          pr_warning("Forcing miimon to 100msec\n");
                          miimon = 100;
                  }
          }
  
          if (bond_mode == BOND_MODE_ALB) {
                  pr_notice("In ALB mode you might experience client disconnections upon reconnection of a link if the bonding module updelay parameter (%d msec) is incompatible with the forwarding delay time of the switch\n",
                            updelay);
          }
  
          if (!miimon) {
                  if (updelay || downdelay) {
                          /* just warn the user the up/down delay will have
                           * no effect since miimon is zero...
                           */
                          pr_warning("Warning: miimon module parameter not set and updelay (%d) or downdelay (%d) module parameter is set; updelay and downdelay have no effect unless miimon is set\n",
                                     updelay, downdelay);
                  }
          } else {
                  /* don't allow arp monitoring */
                  if (arp_interval) {
                          pr_warning("Warning: miimon (%d) and arp_interval (%d) can't be used simultaneously, disabling ARP monitoring\n",
                                     miimon, arp_interval);
                          arp_interval = 0;
                  }
  
                  if ((updelay % miimon) != 0) {
                          pr_warning("Warning: updelay (%d) is not a multiple of miimon (%d), updelay rounded to %d ms\n",
                                     updelay, miimon,
                                     (updelay / miimon) * miimon);
                  }
  
                  updelay /= miimon;
  
                  if ((downdelay % miimon) != 0) {
                          pr_warning("Warning: downdelay (%d) is not a multiple of miimon (%d), downdelay rounded to %d ms\n",
                                     downdelay, miimon,
                                     (downdelay / miimon) * miimon);
                  }
  
                  downdelay /= miimon;
          }
  
          if (arp_interval < 0) {
                  pr_warning("Warning: arp_interval module parameter (%d) , not in range 0-%d, so it was reset to %d\n",
                             arp_interval, INT_MAX, BOND_LINK_ARP_INTERV);
                  arp_interval = BOND_LINK_ARP_INTERV;
          }
  
          for (arp_ip_count = 0;
               (arp_ip_count < BOND_MAX_ARP_TARGETS) && arp_ip_target[arp_ip_count];
               arp_ip_count++) {
                  /* not complete check, but should be good enough to
                     catch mistakes */
                  __be32 ip = in_aton(arp_ip_target[arp_ip_count]);
                  if (!isdigit(arp_ip_target[arp_ip_count][0]) ||
                      ip == 0 || ip == htonl(INADDR_BROADCAST)) {
                          pr_warning("Warning: bad arp_ip_target module parameter (%s), ARP monitoring will not be performed\n",
                                     arp_ip_target[arp_ip_count]);
                          arp_interval = 0;
                  } else {
                          arp_target[arp_ip_count] = ip;
                  }
          }
  
          if (arp_interval && !arp_ip_count) {
                  /* don't allow arping if no arp_ip_target given... */
                  pr_warning("Warning: arp_interval module parameter (%d) specified without providing an arp_ip_target parameter, arp_interval was reset to 0\n",
                             arp_interval);
                  arp_interval = 0;
          }
  
          if (arp_validate) {
                  if (bond_mode != BOND_MODE_ACTIVEBACKUP) {
                          pr_err("arp_validate only supported in active-backup mode\n");
                          return -EINVAL;
                  }
                  if (!arp_interval) {
                          pr_err("arp_validate requires arp_interval\n");
                          return -EINVAL;
                  }
  
                  arp_validate_value = bond_parse_parm(arp_validate,
                                                       arp_validate_tbl);
                  if (arp_validate_value == -1) {
                          pr_err("Error: invalid arp_validate \"%s\"\n",
                                 arp_validate == NULL ? "NULL" : arp_validate);
                          return -EINVAL;
                  }
          } else
                  arp_validate_value = 0;
  
          if (miimon) {
                  pr_info("MII link monitoring set to %d ms\n", miimon);
          } else if (arp_interval) {
                  int i;
  
                  pr_info("ARP monitoring set to %d ms, validate %s, with %d target(s):",
                          arp_interval,
                          arp_validate_tbl[arp_validate_value].modename,
                          arp_ip_count);
  
                  for (i = 0; i < arp_ip_count; i++)
                          pr_info(" %s", arp_ip_target[i]);
  
                  pr_info("\n");
  
          } else if (max_bonds) {
                  /* miimon and arp_interval not set, we need one so things
                   * work as expected, see bonding.txt for details
                   */
                  pr_debug("Warning: either miimon or arp_interval and arp_ip_target module parameters must be specified, otherwise bonding will not detect link failures! see bonding.txt for details.\n");
          }
  
          if (primary && !USES_PRIMARY(bond_mode)) {
                  /* currently, using a primary only makes sense
                   * in active backup, TLB or ALB modes
                   */
                  pr_warning("Warning: %s primary device specified but has no effect in %s mode\n",
                             primary, bond_mode_name(bond_mode));
                  primary = NULL;
          }
  
          if (primary && primary_reselect) {
                  primary_reselect_value = bond_parse_parm(primary_reselect,
                                                           pri_reselect_tbl);
                  if (primary_reselect_value == -1) {
                          pr_err("Error: Invalid primary_reselect \"%s\"\n",
                                 primary_reselect ==
                                          NULL ? "NULL" : primary_reselect);
                          return -EINVAL;
                  }
          } else {
                  primary_reselect_value = BOND_PRI_RESELECT_ALWAYS;
          }
  
          if (fail_over_mac) {
                  fail_over_mac_value = bond_parse_parm(fail_over_mac,
                                                        fail_over_mac_tbl);
                  if (fail_over_mac_value == -1) {
                          pr_err("Error: invalid fail_over_mac \"%s\"\n",
                                 arp_validate == NULL ? "NULL" : arp_validate);
                          return -EINVAL;
                  }
  
                  if (bond_mode != BOND_MODE_ACTIVEBACKUP)
                          pr_warning("Warning: fail_over_mac only affects active-backup mode.\n");
          } else {
                  fail_over_mac_value = BOND_FOM_NONE;
          }
  
          /* fill params struct with the proper values */
          params->mode = bond_mode;
          params->xmit_policy = xmit_hashtype;
          params->miimon = miimon;
          params->num_peer_notif = num_peer_notif;
          params->arp_interval = arp_interval;
          params->arp_validate = arp_validate_value;
          params->updelay = updelay;
          params->downdelay = downdelay;
          params->use_carrier = use_carrier;
          params->lacp_fast = lacp_fast;
          params->primary[0] = 0;
          params->primary_reselect = primary_reselect_value;
          params->fail_over_mac = fail_over_mac_value;
          params->tx_queues = tx_queues;
          params->all_slaves_active = all_slaves_active;
          params->resend_igmp = resend_igmp;
          params->min_links = min_links;
  
          if (primary) {
                  strncpy(params->primary, primary, IFNAMSIZ);
                  params->primary[IFNAMSIZ - 1] = 0;
          }
  
          memcpy(params->arp_targets, arp_target, sizeof(arp_target));
  
          return 0;
  }
  
  static struct lock_class_key bonding_netdev_xmit_lock_key;
  static struct lock_class_key bonding_netdev_addr_lock_key;
  static struct lock_class_key bonding_tx_busylock_key;
  
  static void bond_set_lockdep_class_one(struct net_device *dev,
                                         struct netdev_queue *txq,
                                         void *_unused)
  {
          lockdep_set_class(&txq->_xmit_lock,
                            &bonding_netdev_xmit_lock_key);
  }
  
  static void bond_set_lockdep_class(struct net_device *dev)
  {
          lockdep_set_class(&dev->addr_list_lock,
                            &bonding_netdev_addr_lock_key);
          netdev_for_each_tx_queue(dev, bond_set_lockdep_class_one, NULL);
          dev->qdisc_tx_busylock = &bonding_tx_busylock_key;
  }
  
  /*
   * Called from registration process
   */
  static int bond_init(struct net_device *bond_dev)
  {
          struct bonding *bond = netdev_priv(bond_dev);
          struct bond_net *bn = net_generic(dev_net(bond_dev), bond_net_id);
          struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
  
          pr_debug("Begin bond_init for %s\n", bond_dev->name);
  
          /*
           * Initialize locks that may be required during
           * en/deslave operations.  All of the bond_open work
           * (of which this is part) should really be moved to
           * a phase prior to dev_open
           */
          spin_lock_init(&(bond_info->tx_hashtbl_lock));
          spin_lock_init(&(bond_info->rx_hashtbl_lock));
  
          bond->wq = create_singlethread_workqueue(bond_dev->name);
          if (!bond->wq)
                  return -ENOMEM;
  
          bond_set_lockdep_class(bond_dev);
  
          list_add_tail(&bond->bond_list, &bn->dev_list);
  
          bond_prepare_sysfs_group(bond);
  
          bond_debug_register(bond);
  
          __hw_addr_init(&bond->mc_list);
          return 0;
  }
  
  static int bond_validate(struct nlattr *tb[], struct nlattr *data[])
  {
          if (tb[IFLA_ADDRESS]) {
                  if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
                          return -EINVAL;
                  if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
                          return -EADDRNOTAVAIL;
          }
          return 0;
  }
  
  static unsigned int bond_get_num_tx_queues(void)
  {
          return tx_queues;
  }
  
  static struct rtnl_link_ops bond_link_ops __read_mostly = {
          .kind                   = "bond",
          .priv_size              = sizeof(struct bonding),
          .setup                  = bond_setup,
          .validate               = bond_validate,
          .get_num_tx_queues      = bond_get_num_tx_queues,
          .get_num_rx_queues      = bond_get_num_tx_queues, /* Use the same number
                                                               as for TX queues */
  };
  
  /* Create a new bond based on the specified name and bonding parameters.
   * If name is NULL, obtain a suitable "bond%d" name for us.
   * Caller must NOT hold rtnl_lock; we need to release it here before we
   * set up our sysfs entries.
   */
  int bond_create(struct net *net, const char *name)
  {
          struct net_device *bond_dev;
          int res;
  
          rtnl_lock();
  
          bond_dev = alloc_netdev_mq(sizeof(struct bonding),
                                     name ? name : "bond%d",
                                     bond_setup, tx_queues);
          if (!bond_dev) {
                  pr_err("%s: eek! can't alloc netdev!\n", name);
                  rtnl_unlock();
                  return -ENOMEM;
          }
  
          dev_net_set(bond_dev, net);
          bond_dev->rtnl_link_ops = &bond_link_ops;
  
          res = register_netdevice(bond_dev);
  
          netif_carrier_off(bond_dev);
  
          rtnl_unlock();
          if (res < 0)
                  bond_destructor(bond_dev);
          return res;
  }
  
  static int __net_init bond_net_init(struct net *net)
  {
          struct bond_net *bn = net_generic(net, bond_net_id);
  
          bn->net = net;
          INIT_LIST_HEAD(&bn->dev_list);
  
          bond_create_proc_dir(bn);
          bond_create_sysfs(bn);
          
          return 0;
  }
  
  static void __net_exit bond_net_exit(struct net *net)
  {
          struct bond_net *bn = net_generic(net, bond_net_id);
  
          bond_destroy_sysfs(bn);
          bond_destroy_proc_dir(bn);
  }
  
  static struct pernet_operations bond_net_ops = {
          .init = bond_net_init,
          .exit = bond_net_exit,
          .id   = &bond_net_id,
          .size = sizeof(struct bond_net),
  };
  
  static int __init bonding_init(void)
  {
          int i;
          int res;
  
          pr_info("%s", bond_version);
  
          res = bond_check_params(&bonding_defaults);
          if (res)
                  goto out;
  
          res = register_pernet_subsys(&bond_net_ops);
          if (res)
                  goto out;
  
          res = rtnl_link_register(&bond_link_ops);
          if (res)
                  goto err_link;
  
          bond_create_debugfs();
  
          for (i = 0; i < max_bonds; i++) {
                  res = bond_create(&init_net, NULL);
                  if (res)
                          goto err;
          }
  
          register_netdevice_notifier(&bond_netdev_notifier);
  out:
          return res;
  err:
          rtnl_link_unregister(&bond_link_ops);
  err_link:
          unregister_pernet_subsys(&bond_net_ops);
          goto out;
  
  }
  
  static void __exit bonding_exit(void)
  {
          unregister_netdevice_notifier(&bond_netdev_notifier);
  
          bond_destroy_debugfs();
  
          rtnl_link_unregister(&bond_link_ops);
          unregister_pernet_subsys(&bond_net_ops);
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
          /*
           * Make sure we don't have an imbalance on our netpoll blocking
           */
          WARN_ON(atomic_read(&netpoll_block_tx));
  #endif
  }
  
  module_init(bonding_init);
  module_exit(bonding_exit);
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRV_VERSION);
  MODULE_DESCRIPTION(DRV_DESCRIPTION ", v" DRV_VERSION);
  MODULE_AUTHOR("Thomas Davis, tadavis@lbl.gov and many others");
  MODULE_ALIAS_RTNL_LINK("bond");