text: /*
   * originally based on the dummy device.
   *
   * Copyright 1999, Thomas Davis, tadavis@lbl.gov.
   * Licensed under the GPL. Based on dummy.c, and eql.c devices.
   *
   * bonding.c: an Ethernet Bonding driver
   *
   * This is useful to talk to a Cisco EtherChannel compatible equipment:
   *	Cisco 5500
   *	Sun Trunking (Solaris)
   *	Alteon AceDirector Trunks
   *	Linux Bonding
   *	and probably many L2 switches ...
   *
   * How it works:
   *    ifconfig bond0 ipaddress netmask up
   *      will setup a network device, with an ip address.  No mac address
   *	will be assigned at this time.  The hw mac address will come from
   *	the first slave bonded to the channel.  All slaves will then use
   *	this hw mac address.
   *
   *    ifconfig bond0 down
   *         will release all slaves, marking them as down.
   *
   *    ifenslave bond0 eth0
   *	will attach eth0 to bond0 as a slave.  eth0 hw mac address will either
   *	a: be used as initial mac address
   *	b: if a hw mac address already is there, eth0's hw mac address
   *	   will then be set from bond0.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/fcntl.h>
  #include <linux/interrupt.h>
  #include <linux/ptrace.h>
  #include <linux/ioport.h>
  #include <linux/in.h>
  #include <net/ip.h>
  #include <linux/ip.h>
  #include <linux/tcp.h>
  #include <linux/udp.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/init.h>
  #include <linux/timer.h>
  #include <linux/socket.h>
  #include <linux/ctype.h>
  #include <linux/inet.h>
  #include <linux/bitops.h>
  #include <linux/io.h>
  #include <asm/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 <linux/rculist.h>
  #include <net/flow_dissector.h>
  #include <net/switchdev.h>
  #include <net/bonding.h>
  #include <net/bond_3ad.h>
  #include <net/bond_alb.h>
  
  #include "bonding_priv.h"
  
  /*---------------------------- Module parameters ----------------------------*/
  
  /* monitor all links that often (in milliseconds). <=0 disables monitoring */
  
  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;
  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;
  static char *arp_ip_target[BOND_MAX_ARP_TARGETS];
  static char *arp_validate;
  static char *arp_all_targets;
  static char *fail_over_mac;
  static int all_slaves_active;
  static struct bond_params bonding_defaults;
  static int resend_igmp = BOND_DEFAULT_RESEND_IGMP;
  static int packets_per_slave = 1;
  static int lp_interval = BOND_ALB_DEFAULT_LP_INTERVAL;
  
  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, 3 for encap layer 2+3, "
  				   "4 for encap layer 3+4");
  module_param(arp_interval, int, 0);
  MODULE_PARM_DESC(arp_interval, "arp interval in milliseconds");
  module_param_array(arp_ip_target, charp, NULL, 0);
  MODULE_PARM_DESC(arp_ip_target, "arp targets in n.n.n.n form");
  module_param(arp_validate, charp, 0);
  MODULE_PARM_DESC(arp_validate, "validate src/dst of ARP probes; "
  			       "0 for none (default), 1 for active, "
  			       "2 for backup, 3 for all");
  module_param(arp_all_targets, charp, 0);
  MODULE_PARM_DESC(arp_all_targets, "fail on any/all arp targets timeout; 0 for any (default), 1 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");
  module_param(packets_per_slave, int, 0);
  MODULE_PARM_DESC(packets_per_slave, "Packets to send per slave in balance-rr "
  				    "mode; 0 for a random slave, 1 packet per "
  				    "slave (default), >1 packets per slave.");
  module_param(lp_interval, uint, 0);
  MODULE_PARM_DESC(lp_interval, "The number of seconds between instances where "
  			      "the bonding driver sends learning packets to "
  			      "each slaves peer switch. The default is 1.");
  
  /*----------------------------- 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;
  
  /*-------------------------- Forward declarations ---------------------------*/
  
  static int bond_init(struct net_device *bond_dev);
  static void bond_uninit(struct net_device *bond_dev);
  static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev,
  						struct rtnl_link_stats64 *stats);
  static void bond_slave_arr_handler(struct work_struct *work);
  static bool bond_time_in_interval(struct bonding *bond, unsigned long last_act,
  				  int mod);
  
  /*---------------------------- 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 < BOND_MODE_ROUNDROBIN || mode > BOND_MODE_ALB)
  		return "unknown";
  
  	return names[mode];
  }
  
  /*---------------------------------- VLAN -----------------------------------*/
  
  /**
   * 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
   */
  void 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);
  }
  
  /* 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,
  				__be16 proto, u16 vid)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct slave *slave, *rollback_slave;
  	struct list_head *iter;
  	int res;
  
  	bond_for_each_slave(bond, slave, iter) {
  		res = vlan_vid_add(slave->dev, proto, vid);
  		if (res)
  			goto unwind;
  	}
  
  	return 0;
  
  unwind:
  	/* unwind to the slave that failed */
  	bond_for_each_slave(bond, rollback_slave, iter) {
  		if (rollback_slave == slave)
  			break;
  
  		vlan_vid_del(rollback_slave->dev, proto, 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,
  				 __be16 proto, u16 vid)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct list_head *iter;
  	struct slave *slave;
  
  	bond_for_each_slave(bond, slave, iter)
  		vlan_vid_del(slave->dev, proto, vid);
  
  	if (bond_is_lb(bond))
  		bond_alb_clear_vlan(bond, vid);
  
  	return 0;
  }
  
  /*------------------------------- 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.
   */
  int bond_set_carrier(struct bonding *bond)
  {
  	struct list_head *iter;
  	struct slave *slave;
  
  	if (!bond_has_slaves(bond))
  		goto down;
  
  	if (BOND_MODE(bond) == BOND_MODE_8023AD)
  		return bond_3ad_set_carrier(bond);
  
  	bond_for_each_slave(bond, slave, iter) {
  		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;
  }
  
  const char *bond_slave_link_status(s8 link)
  {
  	switch (link) {
  	case BOND_LINK_UP:
  		return "up";
  	case BOND_LINK_FAIL:
  		return "going down";
  	case BOND_LINK_DOWN:
  		return "down";
  	case BOND_LINK_BACK:
  		return "going back";
  	default:
  		return "unknown";
  	}
  }
  
  /* 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)
  {
  	struct list_head *iter;
  	int err = 0;
  
  	if (bond_uses_primary(bond)) {
  		struct slave *curr_active = rtnl_dereference(bond->curr_active_slave);
  
  		if (curr_active)
  			err = dev_set_promiscuity(curr_active->dev, inc);
  	} else {
  		struct slave *slave;
  
  		bond_for_each_slave(bond, slave, iter) {
  			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)
  {
  	struct list_head *iter;
  	int err = 0;
  
  	if (bond_uses_primary(bond)) {
  		struct slave *curr_active = rtnl_dereference(bond->curr_active_slave);
  
  		if (curr_active)
  			err = dev_set_allmulti(curr_active->dev, inc);
  	} else {
  		struct slave *slave;
  
  		bond_for_each_slave(bond, slave, iter) {
  			err = dev_set_allmulti(slave->dev, inc);
  			if (err)
  				return err;
  		}
  	}
  	return err;
  }
  
  /* 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_delayed(struct work_struct *work)
  {
  	struct bonding *bond = container_of(work, struct bonding,
  					    mcast_work.work);
  
  	if (!rtnl_trylock()) {
  		queue_delayed_work(bond->wq, &bond->mcast_work, 1);
  		return;
  	}
  	call_netdevice_notifiers(NETDEV_RESEND_IGMP, bond->dev);
  
  	if (bond->igmp_retrans > 1) {
  		bond->igmp_retrans--;
  		queue_delayed_work(bond->wq, &bond->mcast_work, HZ/5);
  	}
  	rtnl_unlock();
  }
  
  /* Flush bond's hardware addresses from slave */
  static void bond_hw_addr_flush(struct net_device *bond_dev,
  			       struct net_device *slave_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  
  	dev_uc_unsync(slave_dev, bond_dev);
  	dev_mc_unsync(slave_dev, bond_dev);
  
  	if (BOND_MODE(bond) == 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 hardware address list and promisc/allmulti for the new and
   * old active slaves (if any).  Modes that are not using primary keep all
   * slaves up date at all times; only the modes that use primary need to call
   * this function to swap these settings during a failover.
   */
  static void bond_hw_addr_swap(struct bonding *bond, struct slave *new_active,
  			      struct slave *old_active)
  {
  	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);
  
  		bond_hw_addr_flush(bond->dev, old_active->dev);
  	}
  
  	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);
  
  		netif_addr_lock_bh(bond->dev);
  		dev_uc_sync(new_active->dev, bond->dev);
  		dev_mc_sync(new_active->dev, bond->dev);
  		netif_addr_unlock_bh(bond->dev);
  	}
  }
  
  /**
   * bond_set_dev_addr - clone slave's address to bond
   * @bond_dev: bond net device
   * @slave_dev: slave net device
   *
   * Should be called with RTNL held.
   */
  static void bond_set_dev_addr(struct net_device *bond_dev,
  			      struct net_device *slave_dev)
  {
  	netdev_dbg(bond_dev, "bond_dev=%p slave_dev=%p slave_dev->addr_len=%d\n",
  		   bond_dev, slave_dev, slave_dev->addr_len);
  	memcpy(bond_dev->dev_addr, slave_dev->dev_addr, slave_dev->addr_len);
  	bond_dev->addr_assign_type = NET_ADDR_STOLEN;
  	call_netdevice_notifiers(NETDEV_CHANGEADDR, bond_dev);
  }
  
  static struct slave *bond_get_old_active(struct bonding *bond,
  					 struct slave *new_active)
  {
  	struct slave *slave;
  	struct list_head *iter;
  
  	bond_for_each_slave(bond, slave, iter) {
  		if (slave == new_active)
  			continue;
  
  		if (ether_addr_equal(bond->dev->dev_addr, slave->dev->dev_addr))
  			return slave;
  	}
  
  	return NULL;
  }
  
  /* bond_do_fail_over_mac
   *
   * Perform special MAC address swapping for fail_over_mac settings
   *
   * Called with RTNL
   */
  static void bond_do_fail_over_mac(struct bonding *bond,
  				  struct slave *new_active,
  				  struct slave *old_active)
  {
  	u8 tmp_mac[ETH_ALEN];
  	struct sockaddr saddr;
  	int rv;
  
  	switch (bond->params.fail_over_mac) {
  	case BOND_FOM_ACTIVE:
  		if (new_active)
  			bond_set_dev_addr(bond->dev, new_active->dev);
  		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;
  
  		if (!old_active)
  			old_active = bond_get_old_active(bond, new_active);
  
  		if (old_active) {
  			ether_addr_copy(tmp_mac, new_active->dev->dev_addr);
  			ether_addr_copy(saddr.sa_data,
  					old_active->dev->dev_addr);
  			saddr.sa_family = new_active->dev->type;
  		} else {
  			ether_addr_copy(saddr.sa_data, bond->dev->dev_addr);
  			saddr.sa_family = bond->dev->type;
  		}
  
  		rv = dev_set_mac_address(new_active->dev, &saddr);
  		if (rv) {
  			netdev_err(bond->dev, "Error %d setting MAC of slave %s\n",
  				   -rv, new_active->dev->name);
  			goto out;
  		}
  
  		if (!old_active)
  			goto out;
  
  		ether_addr_copy(saddr.sa_data, tmp_mac);
  		saddr.sa_family = old_active->dev->type;
  
  		rv = dev_set_mac_address(old_active->dev, &saddr);
  		if (rv)
  			netdev_err(bond->dev, "Error %d setting MAC of slave %s\n",
  				   -rv, new_active->dev->name);
  out:
  		break;
  	default:
  		netdev_err(bond->dev, "bond_do_fail_over_mac impossible: bad policy %d\n",
  			   bond->params.fail_over_mac);
  		break;
  	}
  
  }
  
  static struct slave *bond_choose_primary_or_current(struct bonding *bond)
  {
  	struct slave *prim = rtnl_dereference(bond->primary_slave);
  	struct slave *curr = rtnl_dereference(bond->curr_active_slave);
  
  	if (!prim || prim->link != BOND_LINK_UP) {
  		if (!curr || curr->link != BOND_LINK_UP)
  			return NULL;
  		return curr;
  	}
  
  	if (bond->force_primary) {
  		bond->force_primary = false;
  		return prim;
  	}
  
  	if (!curr || curr->link != BOND_LINK_UP)
  		return prim;
  
  	/* At this point, prim and curr are both up */
  	switch (bond->params.primary_reselect) {
  	case BOND_PRI_RESELECT_ALWAYS:
  		return prim;
  	case BOND_PRI_RESELECT_BETTER:
  		if (prim->speed < curr->speed)
  			return curr;
  		if (prim->speed == curr->speed && prim->duplex <= curr->duplex)
  			return curr;
  		return prim;
  	case BOND_PRI_RESELECT_FAILURE:
  		return curr;
  	default:
  		netdev_err(bond->dev, "impossible primary_reselect %d\n",
  			   bond->params.primary_reselect);
  		return curr;
  	}
  }
  
  /**
   * bond_find_best_slave - select the best available slave to be the active one
   * @bond: our bonding struct
   */
  static struct slave *bond_find_best_slave(struct bonding *bond)
  {
  	struct slave *slave, *bestslave = NULL;
  	struct list_head *iter;
  	int mintime = bond->params.updelay;
  
  	slave = bond_choose_primary_or_current(bond);
  	if (slave)
  		return slave;
  
  	bond_for_each_slave(bond, slave, iter) {
  		if (slave->link == BOND_LINK_UP)
  			return slave;
  		if (slave->link == BOND_LINK_BACK && bond_slave_is_up(slave) &&
  		    slave->delay < mintime) {
  			mintime = slave->delay;
  			bestslave = slave;
  		}
  	}
  
  	return bestslave;
  }
  
  static bool bond_should_notify_peers(struct bonding *bond)
  {
  	struct slave *slave;
  
  	rcu_read_lock();
  	slave = rcu_dereference(bond->curr_active_slave);
  	rcu_read_unlock();
  
  	netdev_dbg(bond->dev, "bond_should_notify_peers: slave %s\n",
  		   slave ? slave->dev->name : "NULL");
  
  	if (!slave || !bond->send_peer_notif ||
  	    !netif_carrier_ok(bond->dev) ||
  	    test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
  		return false;
  
  	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.
   *
   * Caller must hold RTNL.
   */
  void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
  {
  	struct slave *old_active;
  
  	ASSERT_RTNL();
  
  	old_active = rtnl_dereference(bond->curr_active_slave);
  
  	if (old_active == new_active)
  		return;
  
  	if (new_active) {
  		new_active->last_link_up = jiffies;
  
  		if (new_active->link == BOND_LINK_BACK) {
  			if (bond_uses_primary(bond)) {
  				netdev_info(bond->dev, "making interface %s the new active one %d ms earlier\n",
  					    new_active->dev->name,
  					    (bond->params.updelay - new_active->delay) * bond->params.miimon);
  			}
  
  			new_active->delay = 0;
  			bond_set_slave_link_state(new_active, BOND_LINK_UP,
  						  BOND_SLAVE_NOTIFY_NOW);
  
  			if (BOND_MODE(bond) == 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 (bond_uses_primary(bond)) {
  				netdev_info(bond->dev, "making interface %s the new active one\n",
  					    new_active->dev->name);
  			}
  		}
  	}
  
  	if (bond_uses_primary(bond))
  		bond_hw_addr_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,
  						      BOND_SLAVE_NOTIFY_NOW);
  		if (new_active)
  			bond_set_slave_active_flags(new_active,
  						    BOND_SLAVE_NOTIFY_NOW);
  	} else {
  		rcu_assign_pointer(bond->curr_active_slave, new_active);
  	}
  
  	if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP) {
  		if (old_active)
  			bond_set_slave_inactive_flags(old_active,
  						      BOND_SLAVE_NOTIFY_NOW);
  
  		if (new_active) {
  			bool should_notify_peers = false;
  
  			bond_set_slave_active_flags(new_active,
  						    BOND_SLAVE_NOTIFY_NOW);
  
  			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);
  			}
  
  			call_netdevice_notifiers(NETDEV_BONDING_FAILOVER, bond->dev);
  			if (should_notify_peers)
  				call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
  							 bond->dev);
  		}
  	}
  
  	/* 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) &&
  	    ((bond_uses_primary(bond) && new_active) ||
  	     BOND_MODE(bond) == BOND_MODE_ROUNDROBIN)) {
  		bond->igmp_retrans = bond->params.resend_igmp;
  		queue_delayed_work(bond->wq, &bond->mcast_work, 1);
  	}
  }
  
  /**
   * 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 RTNL.
   */
  void bond_select_active_slave(struct bonding *bond)
  {
  	struct slave *best_slave;
  	int rv;
  
  	ASSERT_RTNL();
  
  	best_slave = bond_find_best_slave(bond);
  	if (best_slave != rtnl_dereference(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)) {
  			netdev_info(bond->dev, "first active interface up!\n");
  		} else {
  			netdev_info(bond->dev, "now running without any active interface!\n");
  		}
  	}
  }
  
  #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_KERNEL);
  	err = -ENOMEM;
  	if (!np)
  		goto out;
  
  	err = __netpoll_setup(np, slave->dev);
  	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_async(np);
  }
  
  static void bond_poll_controller(struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct slave *slave = NULL;
  	struct list_head *iter;
  	struct ad_info ad_info;
  	struct netpoll_info *ni;
  	const struct net_device_ops *ops;
  
  	if (BOND_MODE(bond) == BOND_MODE_8023AD)
  		if (bond_3ad_get_active_agg_info(bond, &ad_info))
  			return;
  
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		ops = slave->dev->netdev_ops;
  		if (!bond_slave_is_up(slave) || !ops->ndo_poll_controller)
  			continue;
  
  		if (BOND_MODE(bond) == BOND_MODE_8023AD) {
  			struct aggregator *agg =
  			    SLAVE_AD_INFO(slave)->port.aggregator;
  
  			if (agg &&
  			    agg->aggregator_identifier != ad_info.aggregator_id)
  				continue;
  		}
  
  		ni = rcu_dereference_bh(slave->dev->npinfo);
  		if (down_trylock(&ni->dev_lock))
  			continue;
  		ops->ndo_poll_controller(slave->dev);
  		up(&ni->dev_lock);
  	}
  }
  
  static void bond_netpoll_cleanup(struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct list_head *iter;
  	struct slave *slave;
  
  	bond_for_each_slave(bond, slave, iter)
  		if (bond_slave_is_up(slave))
  			slave_disable_netpoll(slave);
  }
  
  static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
  {
  	struct bonding *bond = netdev_priv(dev);
  	struct list_head *iter;
  	struct slave *slave;
  	int err = 0;
  
  	bond_for_each_slave(bond, slave, iter) {
  		err = slave_enable_netpoll(slave);
  		if (err) {
  			bond_netpoll_cleanup(dev);
  			break;
  		}
  	}
  	return err;
  }
  #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 netdev_features_t bond_fix_features(struct net_device *dev,
  					   netdev_features_t features)
  {
  	struct bonding *bond = netdev_priv(dev);
  	struct list_head *iter;
  	netdev_features_t mask;
  	struct slave *slave;
  
  	mask = features;
  
  	features &= ~NETIF_F_ONE_FOR_ALL;
  	features |= NETIF_F_ALL_FOR_ALL;
  
  	bond_for_each_slave(bond, slave, iter) {
  		features = netdev_increment_features(features,
  						     slave->dev->features,
  						     mask);
  	}
  	features = netdev_add_tso_features(features, mask);
  
  	return features;
  }
  
  #define BOND_VLAN_FEATURES	(NETIF_F_HW_CSUM | NETIF_F_SG | \
  				 NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
  				 NETIF_F_HIGHDMA | NETIF_F_LRO)
  
  #define BOND_ENC_FEATURES	(NETIF_F_HW_CSUM | NETIF_F_SG | \
  				 NETIF_F_RXCSUM | NETIF_F_ALL_TSO)
  
  static void bond_compute_features(struct bonding *bond)
  {
  	unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE |
  					IFF_XMIT_DST_RELEASE_PERM;
  	netdev_features_t vlan_features = BOND_VLAN_FEATURES;
  	netdev_features_t enc_features  = BOND_ENC_FEATURES;
  	struct net_device *bond_dev = bond->dev;
  	struct list_head *iter;
  	struct slave *slave;
  	unsigned short max_hard_header_len = ETH_HLEN;
  	unsigned int gso_max_size = GSO_MAX_SIZE;
  	u16 gso_max_segs = GSO_MAX_SEGS;
  
  	if (!bond_has_slaves(bond))
  		goto done;
  	vlan_features &= NETIF_F_ALL_FOR_ALL;
  
  	bond_for_each_slave(bond, slave, iter) {
  		vlan_features = netdev_increment_features(vlan_features,
  			slave->dev->vlan_features, BOND_VLAN_FEATURES);
  
  		enc_features = netdev_increment_features(enc_features,
  							 slave->dev->hw_enc_features,
  							 BOND_ENC_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->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL;
  	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);
  
  	bond_dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
  	if ((bond_dev->priv_flags & IFF_XMIT_DST_RELEASE_PERM) &&
  	    dst_release_flag == (IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM))
  		bond_dev->priv_flags |= IFF_XMIT_DST_RELEASE;
  
  	netdev_change_features(bond_dev);
  }
  
  static void bond_setup_by_slave(struct net_device *bond_dev,
  				struct net_device *slave_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);
  }
  
  /* 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_MODE(bond) == 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;
  
  	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_MODE(bond) == 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;
  		}
  		ether_addr_copy(eth_hdr(skb)->h_dest, bond->dev->dev_addr);
  	}
  
  	return ret;
  }
  
  static enum netdev_lag_tx_type bond_lag_tx_type(struct bonding *bond)
  {
  	switch (BOND_MODE(bond)) {
  	case BOND_MODE_ROUNDROBIN:
  		return NETDEV_LAG_TX_TYPE_ROUNDROBIN;
  	case BOND_MODE_ACTIVEBACKUP:
  		return NETDEV_LAG_TX_TYPE_ACTIVEBACKUP;
  	case BOND_MODE_BROADCAST:
  		return NETDEV_LAG_TX_TYPE_BROADCAST;
  	case BOND_MODE_XOR:
  	case BOND_MODE_8023AD:
  		return NETDEV_LAG_TX_TYPE_HASH;
  	default:
  		return NETDEV_LAG_TX_TYPE_UNKNOWN;
  	}
  }
  
  static int bond_master_upper_dev_link(struct bonding *bond, struct slave *slave)
  {
  	struct netdev_lag_upper_info lag_upper_info;
  	int err;
  
  	lag_upper_info.tx_type = bond_lag_tx_type(bond);
  	err = netdev_master_upper_dev_link(slave->dev, bond->dev, slave,
  					   &lag_upper_info);
  	if (err)
  		return err;
  	rtmsg_ifinfo(RTM_NEWLINK, slave->dev, IFF_SLAVE, GFP_KERNEL);
  	return 0;
  }
  
  static void bond_upper_dev_unlink(struct bonding *bond, struct slave *slave)
  {
  	netdev_upper_dev_unlink(slave->dev, bond->dev);
  	slave->dev->flags &= ~IFF_SLAVE;
  	rtmsg_ifinfo(RTM_NEWLINK, slave->dev, IFF_SLAVE, GFP_KERNEL);
  }
  
  static struct slave *bond_alloc_slave(struct bonding *bond)
  {
  	struct slave *slave = NULL;
  
  	slave = kzalloc(sizeof(struct slave), GFP_KERNEL);
  	if (!slave)
  		return NULL;
  
  	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
  		SLAVE_AD_INFO(slave) = kzalloc(sizeof(struct ad_slave_info),
  					       GFP_KERNEL);
  		if (!SLAVE_AD_INFO(slave)) {
  			kfree(slave);
  			return NULL;
  		}
  	}
  	return slave;
  }
  
  static void bond_free_slave(struct slave *slave)
  {
  	struct bonding *bond = bond_get_bond_by_slave(slave);
  
  	if (BOND_MODE(bond) == BOND_MODE_8023AD)
  		kfree(SLAVE_AD_INFO(slave));
  
  	kfree(slave);
  }
  
  static void bond_fill_ifbond(struct bonding *bond, struct ifbond *info)
  {
  	info->bond_mode = BOND_MODE(bond);
  	info->miimon = bond->params.miimon;
  	info->num_slaves = bond->slave_cnt;
  }
  
  static void bond_fill_ifslave(struct slave *slave, struct ifslave *info)
  {
  	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;
  }
  
  static void bond_netdev_notify(struct net_device *dev,
  			       struct netdev_bonding_info *info)
  {
  	rtnl_lock();
  	netdev_bonding_info_change(dev, info);
  	rtnl_unlock();
  }
  
  static void bond_netdev_notify_work(struct work_struct *_work)
  {
  	struct netdev_notify_work *w =
  		container_of(_work, struct netdev_notify_work, work.work);
  
  	bond_netdev_notify(w->dev, &w->bonding_info);
  	dev_put(w->dev);
  	kfree(w);
  }
  
  void bond_queue_slave_event(struct slave *slave)
  {
  	struct bonding *bond = slave->bond;
  	struct netdev_notify_work *nnw = kzalloc(sizeof(*nnw), GFP_ATOMIC);
  
  	if (!nnw)
  		return;
  
  	dev_hold(slave->dev);
  	nnw->dev = slave->dev;
  	bond_fill_ifslave(slave, &nnw->bonding_info.slave);
  	bond_fill_ifbond(bond, &nnw->bonding_info.master);
  	INIT_DELAYED_WORK(&nnw->work, bond_netdev_notify_work);
  
  	queue_delayed_work(slave->bond->wq, &nnw->work, 0);
  }
  
  void bond_lower_state_changed(struct slave *slave)
  {
  	struct netdev_lag_lower_state_info info;
  
  	info.link_up = slave->link == BOND_LINK_UP ||
  		       slave->link == BOND_LINK_FAIL;
  	info.tx_enabled = bond_is_active_slave(slave);
  	netdev_lower_state_changed(slave->dev, &info);
  }
  
  /* 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, *prev_slave;
  	struct sockaddr addr;
  	int link_reporting;
  	int res = 0, i;
  
  	if (!bond->params.use_carrier &&
  	    slave_dev->ethtool_ops->get_link == NULL &&
  	    slave_ops->ndo_do_ioctl == NULL) {
  		netdev_warn(bond_dev, "no link monitoring support for %s\n",
  			    slave_dev->name);
  	}
  
  	/* already enslaved */
  	if (slave_dev->flags & IFF_SLAVE) {
  		netdev_dbg(bond_dev, "Error: Device was already enslaved\n");
  		return -EBUSY;
  	}
  
  	if (bond_dev == slave_dev) {
  		netdev_err(bond_dev, "cannot enslave bond to itself.\n");
  		return -EPERM;
  	}
  
  	/* vlan challenged mutual exclusion */
  	/* no need to lock since we're protected by rtnl_lock */
  	if (slave_dev->features & NETIF_F_VLAN_CHALLENGED) {
  		netdev_dbg(bond_dev, "%s is NETIF_F_VLAN_CHALLENGED\n",
  			   slave_dev->name);
  		if (vlan_uses_dev(bond_dev)) {
  			netdev_err(bond_dev, "Error: cannot enslave VLAN challenged slave %s on VLAN enabled bond %s\n",
  				   slave_dev->name, bond_dev->name);
  			return -EPERM;
  		} else {
  			netdev_warn(bond_dev, "enslaved VLAN challenged slave %s. Adding VLANs will be blocked as long as %s is part of bond %s\n",
  				    slave_dev->name, slave_dev->name,
  				    bond_dev->name);
  		}
  	} else {
  		netdev_dbg(bond_dev, "%s is !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) {
  		netdev_err(bond_dev, "%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_has_slaves(bond)) {
  		if (bond_dev->type != slave_dev->type) {
  			netdev_dbg(bond_dev, "change device type from %d to %d\n",
  				   bond_dev->type, slave_dev->type);
  
  			res = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE,
  						       bond_dev);
  			res = notifier_to_errno(res);
  			if (res) {
  				netdev_err(bond_dev, "refused to change device type\n");
  				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) {
  		netdev_err(bond_dev, "%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) {
  		netdev_warn(bond_dev, "The slave device specified does not support setting the MAC address\n");
  		if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP &&
  		    bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
  			if (!bond_has_slaves(bond)) {
  				bond->params.fail_over_mac = BOND_FOM_ACTIVE;
  				netdev_warn(bond_dev, "Setting fail_over_mac to active for active-backup mode\n");
  			} else {
  				netdev_err(bond_dev, "The slave device specified does not support setting the MAC address, but fail_over_mac is not set to active\n");
  				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 (!bond_has_slaves(bond) &&
  	    bond->dev->addr_assign_type == NET_ADDR_RANDOM)
  		bond_set_dev_addr(bond->dev, slave_dev);
  
  	new_slave = bond_alloc_slave(bond);
  	if (!new_slave) {
  		res = -ENOMEM;
  		goto err_undo_flags;
  	}
  
  	new_slave->bond = bond;
  	new_slave->dev = slave_dev;
  	/* 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) {
  		netdev_dbg(bond_dev, "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
  	 */
  	ether_addr_copy(new_slave->perm_hwaddr, slave_dev->dev_addr);
  
  	if (!bond->params.fail_over_mac ||
  	    BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
  		/* 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) {
  			netdev_dbg(bond_dev, "Error %d calling set_mac_address\n", res);
  			goto err_restore_mtu;
  		}
  	}
  
  	/* set slave flag before open to prevent IPv6 addrconf */
  	slave_dev->flags |= IFF_SLAVE;
  
  	/* open the slave since the application closed it */
  	res = dev_open(slave_dev);
  	if (res) {
  		netdev_dbg(bond_dev, "Opening slave %s failed\n", slave_dev->name);
  		goto err_restore_mac;
  	}
  
  	slave_dev->priv_flags |= IFF_BONDING;
  	/* initialize slave stats */
  	dev_get_stats(new_slave->dev, &new_slave->slave_stats);
  
  	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 following is handled by
  	 * bond_change_active_slave().
  	 */
  	if (!bond_uses_primary(bond)) {
  		/* 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);
  
  		dev_mc_sync_multiple(slave_dev, bond_dev);
  		dev_uc_sync_multiple(slave_dev, bond_dev);
  
  		netif_addr_unlock_bh(bond_dev);
  	}
  
  	if (BOND_MODE(bond) == 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);
  	}
  
  	res = vlan_vids_add_by_dev(slave_dev, bond_dev);
  	if (res) {
  		netdev_err(bond_dev, "Couldn't add bond vlan ids to %s\n",
  			   slave_dev->name);
  		goto err_close;
  	}
  
  	prev_slave = bond_last_slave(bond);
  
  	new_slave->delay = 0;
  	new_slave->link_failure_count = 0;
  
  	bond_update_speed_duplex(new_slave);
  
  	new_slave->last_rx = jiffies -
  		(msecs_to_jiffies(bond->params.arp_interval) + 1);
  	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
  		new_slave->target_last_arp_rx[i] = new_slave->last_rx;
  
  	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.
  			 */
  			netdev_warn(bond_dev, "MII and ETHTOOL support not available for interface %s, and arp_interval/arp_ip_target module parameters not specified, thus bonding will not detect link failures! see bonding.txt for details\n",
  				    slave_dev->name);
  		} else if (link_reporting == -1) {
  			/* unable get link status using mii/ethtool */
  			netdev_warn(bond_dev, "can't get link status from interface %s; the network driver associated with this interface does not support MII or ETHTOOL link status reporting, thus miimon has no effect on this interface\n",
  				    slave_dev->name);
  		}
  	}
  
  	/* check for initial state */
  	if (bond->params.miimon) {
  		if (bond_check_dev_link(bond, slave_dev, 0) == BMSR_LSTATUS) {
  			if (bond->params.updelay) {
  				bond_set_slave_link_state(new_slave,
  							  BOND_LINK_BACK,
  							  BOND_SLAVE_NOTIFY_NOW);
  				new_slave->delay = bond->params.updelay;
  			} else {
  				bond_set_slave_link_state(new_slave,
  							  BOND_LINK_UP,
  							  BOND_SLAVE_NOTIFY_NOW);
  			}
  		} else {
  			bond_set_slave_link_state(new_slave, BOND_LINK_DOWN,
  						  BOND_SLAVE_NOTIFY_NOW);
  		}
  	} else if (bond->params.arp_interval) {
  		bond_set_slave_link_state(new_slave,
  					  (netif_carrier_ok(slave_dev) ?
  					  BOND_LINK_UP : BOND_LINK_DOWN),
  					  BOND_SLAVE_NOTIFY_NOW);
  	} else {
  		bond_set_slave_link_state(new_slave, BOND_LINK_UP,
  					  BOND_SLAVE_NOTIFY_NOW);
  	}
  
  	if (new_slave->link != BOND_LINK_DOWN)
  		new_slave->last_link_up = jiffies;
  	netdev_dbg(bond_dev, "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"));
  
  	if (bond_uses_primary(bond) && bond->params.primary[0]) {
  		/* if there is a primary slave, remember it */
  		if (strcmp(bond->params.primary, new_slave->dev->name) == 0) {
  			rcu_assign_pointer(bond->primary_slave, new_slave);
  			bond->force_primary = true;
  		}
  	}
  
  	switch (BOND_MODE(bond)) {
  	case BOND_MODE_ACTIVEBACKUP:
  		bond_set_slave_inactive_flags(new_slave,
  					      BOND_SLAVE_NOTIFY_NOW);
  		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, BOND_SLAVE_NOTIFY_NOW);
  		/* if this is the first slave */
  		if (!prev_slave) {
  			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(prev_slave)->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_SLAVE_NOTIFY_NOW);
  		break;
  	default:
  		netdev_dbg(bond_dev, "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 (!rcu_access_pointer(bond->curr_active_slave) &&
  		    new_slave->link == BOND_LINK_UP)
  			rcu_assign_pointer(bond->curr_active_slave, new_slave);
  
  		break;
  	} /* switch(bond_mode) */
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
  	slave_dev->npinfo = bond->dev->npinfo;
  	if (slave_dev->npinfo) {
  		if (slave_enable_netpoll(new_slave)) {
  			netdev_info(bond_dev, "master_dev is using netpoll, but new slave device does not support netpoll\n");
  			res = -EBUSY;
  			goto err_detach;
  		}
  	}
  #endif
  
  	if (!(bond_dev->features & NETIF_F_LRO))
  		dev_disable_lro(slave_dev);
  
  	res = netdev_rx_handler_register(slave_dev, bond_handle_frame,
  					 new_slave);
  	if (res) {
  		netdev_dbg(bond_dev, "Error %d calling netdev_rx_handler_register\n", res);
  		goto err_detach;
  	}
  
  	res = bond_master_upper_dev_link(bond, new_slave);
  	if (res) {
  		netdev_dbg(bond_dev, "Error %d calling bond_master_upper_dev_link\n", res);
  		goto err_unregister;
  	}
  
  	res = bond_sysfs_slave_add(new_slave);
  	if (res) {
  		netdev_dbg(bond_dev, "Error %d calling bond_sysfs_slave_add\n", res);
  		goto err_upper_unlink;
  	}
  
  	bond->slave_cnt++;
  	bond_compute_features(bond);
  	bond_set_carrier(bond);
  
  	if (bond_uses_primary(bond)) {
  		block_netpoll_tx();
  		bond_select_active_slave(bond);
  		unblock_netpoll_tx();
  	}
  
  	if (bond_mode_uses_xmit_hash(bond))
  		bond_update_slave_arr(bond, NULL);
  
  	netdev_info(bond_dev, "Enslaving %s as %s interface with %s link\n",
  		    slave_dev->name,
  		    bond_is_active_slave(new_slave) ? "an active" : "a backup",
  		    new_slave->link != BOND_LINK_DOWN ? "an up" : "a down");
  
  	/* enslave is successful */
  	bond_queue_slave_event(new_slave);
  	return 0;
  
  /* Undo stages on error */
  err_upper_unlink:
  	bond_upper_dev_unlink(bond, new_slave);
  
  err_unregister:
  	netdev_rx_handler_unregister(slave_dev);
  
  err_detach:
  	if (!bond_uses_primary(bond))
  		bond_hw_addr_flush(bond_dev, slave_dev);
  
  	vlan_vids_del_by_dev(slave_dev, bond_dev);
  	if (rcu_access_pointer(bond->primary_slave) == new_slave)
  		RCU_INIT_POINTER(bond->primary_slave, NULL);
  	if (rcu_access_pointer(bond->curr_active_slave) == new_slave) {
  		block_netpoll_tx();
  		bond_change_active_slave(bond, NULL);
  		bond_select_active_slave(bond);
  		unblock_netpoll_tx();
  	}
  	/* either primary_slave or curr_active_slave might've changed */
  	synchronize_rcu();
  	slave_disable_netpoll(new_slave);
  
  err_close:
  	slave_dev->priv_flags &= ~IFF_BONDING;
  	dev_close(slave_dev);
  
  err_restore_mac:
  	slave_dev->flags &= ~IFF_SLAVE;
  	if (!bond->params.fail_over_mac ||
  	    BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
  		/* 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.
  		 */
  		ether_addr_copy(addr.sa_data, new_slave->perm_hwaddr);
  		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:
  	bond_free_slave(new_slave);
  
  err_undo_flags:
  	/* Enslave of first slave has failed and we need to fix master's mac */
  	if (!bond_has_slaves(bond)) {
  		if (ether_addr_equal_64bits(bond_dev->dev_addr,
  					    slave_dev->dev_addr))
  			eth_hw_addr_random(bond_dev);
  		if (bond_dev->type != ARPHRD_ETHER) {
  			dev_close(bond_dev);
  			ether_setup(bond_dev);
  			bond_dev->flags |= IFF_MASTER;
  			bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
  		}
  	}
  
  	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 RTNL-locked. If "all" is true it means that the function is being called
   * while destroying a bond interface and all slaves are being released.
   *
   * The rules for slave state should be:
   *   for Active/Backup:
   *     Active stays on all backups go down
   *   for Bonded connections:
   *     The first up interface should be left on and all others downed.
   */
  static int __bond_release_one(struct net_device *bond_dev,
  			      struct net_device *slave_dev,
  			      bool all)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct slave *slave, *oldcurrent;
  	struct sockaddr addr;
  	int old_flags = bond_dev->flags;
  	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) ||
  	    !netdev_has_upper_dev(slave_dev, bond_dev)) {
  		netdev_dbg(bond_dev, "cannot release %s\n",
  			   slave_dev->name);
  		return -EINVAL;
  	}
  
  	block_netpoll_tx();
  
  	slave = bond_get_slave_by_dev(bond, slave_dev);
  	if (!slave) {
  		/* not a slave of this bond */
  		netdev_info(bond_dev, "%s not enslaved\n",
  			    slave_dev->name);
  		unblock_netpoll_tx();
  		return -EINVAL;
  	}
  
  	bond_set_slave_inactive_flags(slave, BOND_SLAVE_NOTIFY_NOW);
  
  	bond_sysfs_slave_del(slave);
  
  	/* recompute stats just before removing the slave */
  	bond_get_stats(bond->dev, &bond->bond_stats);
  
  	bond_upper_dev_unlink(bond, slave);
  	/* unregister rx_handler early so bond_handle_frame wouldn't be called
  	 * for this slave anymore.
  	 */
  	netdev_rx_handler_unregister(slave_dev);
  
  	if (BOND_MODE(bond) == BOND_MODE_8023AD)
  		bond_3ad_unbind_slave(slave);
  
  	if (bond_mode_uses_xmit_hash(bond))
  		bond_update_slave_arr(bond, slave);
  
  	netdev_info(bond_dev, "Releasing %s interface %s\n",
  		    bond_is_active_slave(slave) ? "active" : "backup",
  		    slave_dev->name);
  
  	oldcurrent = rcu_access_pointer(bond->curr_active_slave);
  
  	RCU_INIT_POINTER(bond->current_arp_slave, NULL);
  
  	if (!all && (!bond->params.fail_over_mac ||
  		     BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP)) {
  		if (ether_addr_equal_64bits(bond_dev->dev_addr, slave->perm_hwaddr) &&
  		    bond_has_slaves(bond))
  			netdev_warn(bond_dev, "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",
  				    slave_dev->name, slave->perm_hwaddr,
  				    bond_dev->name, slave_dev->name);
  	}
  
  	if (rtnl_dereference(bond->primary_slave) == slave)
  		RCU_INIT_POINTER(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.
  		 */
  		bond_alb_deinit_slave(bond, slave);
  	}
  
  	if (all) {
  		RCU_INIT_POINTER(bond->curr_active_slave, NULL);
  	} else if (oldcurrent == slave) {
  		/* Note that we hold RTNL over this sequence, so there
  		 * is no concern that another slave add/remove event
  		 * will interfere.
  		 */
  		bond_select_active_slave(bond);
  	}
  
  	if (!bond_has_slaves(bond)) {
  		bond_set_carrier(bond);
  		eth_hw_addr_random(bond_dev);
  	}
  
  	unblock_netpoll_tx();
  	synchronize_rcu();
  	bond->slave_cnt--;
  
  	if (!bond_has_slaves(bond)) {
  		call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
  		call_netdevice_notifiers(NETDEV_RELEASE, bond->dev);
  	}
  
  	bond_compute_features(bond);
  	if (!(bond_dev->features & NETIF_F_VLAN_CHALLENGED) &&
  	    (old_features & NETIF_F_VLAN_CHALLENGED))
  		netdev_info(bond_dev, "last VLAN challenged slave %s left bond %s - VLAN blocking is removed\n",
  			    slave_dev->name, bond_dev->name);
  
  	vlan_vids_del_by_dev(slave_dev, bond_dev);
  
  	/* If the mode uses primary, then this case was handled above by
  	 * bond_change_active_slave(..., NULL)
  	 */
  	if (!bond_uses_primary(bond)) {
  		/* unset promiscuity level from slave
  		 * NOTE: The NETDEV_CHANGEADDR call above may change the value
  		 * of the IFF_PROMISC flag in the bond_dev, but we need the
  		 * value of that flag before that change, as that was the value
  		 * when this slave was attached, so we cache at the start of the
  		 * function and use it here. Same goes for ALLMULTI below
  		 */
  		if (old_flags & IFF_PROMISC)
  			dev_set_promiscuity(slave_dev, -1);
  
  		/* unset allmulti level from slave */
  		if (old_flags & IFF_ALLMULTI)
  			dev_set_allmulti(slave_dev, -1);
  
  		bond_hw_addr_flush(bond_dev, slave_dev);
  	}
  
  	slave_disable_netpoll(slave);
  
  	/* close slave before restoring its mac address */
  	dev_close(slave_dev);
  
  	if (bond->params.fail_over_mac != BOND_FOM_ACTIVE ||
  	    BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
  		/* restore original ("permanent") mac address */
  		ether_addr_copy(addr.sa_data, slave->perm_hwaddr);
  		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;
  
  	bond_free_slave(slave);
  
  	return 0;
  }
  
  /* A wrapper used because of ndo_del_link */
  int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
  {
  	return __bond_release_one(bond_dev, slave_dev, false);
  }
  
  /* 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_has_slaves(bond)) {
  		bond_dev->priv_flags |= IFF_DISABLE_NETPOLL;
  		netdev_info(bond_dev, "Destroying bond %s\n",
  			    bond_dev->name);
  		bond_remove_proc_entry(bond);
  		unregister_netdevice(bond_dev);
  	}
  	return ret;
  }
  
  static int bond_info_query(struct net_device *bond_dev, struct ifbond *info)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	bond_fill_ifbond(bond, info);
  	return 0;
  }
  
  static int bond_slave_info_query(struct net_device *bond_dev, struct ifslave *info)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct list_head *iter;
  	int i = 0, res = -ENODEV;
  	struct slave *slave;
  
  	bond_for_each_slave(bond, slave, iter) {
  		if (i++ == (int)info->slave_id) {
  			res = 0;
  			bond_fill_ifslave(slave, info);
  			break;
  		}
  	}
  
  	return res;
  }
  
  /*-------------------------------- Monitoring -------------------------------*/
  
  /* called with rcu_read_lock() */
  static int bond_miimon_inspect(struct bonding *bond)
  {
  	int link_state, commit = 0;
  	struct list_head *iter;
  	struct slave *slave;
  	bool ignore_updelay;
  
  	ignore_updelay = !rcu_dereference(bond->curr_active_slave);
  
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		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;
  
  			bond_set_slave_link_state(slave, BOND_LINK_FAIL,
  						  BOND_SLAVE_NOTIFY_LATER);
  			slave->delay = bond->params.downdelay;
  			if (slave->delay) {
  				netdev_info(bond->dev, "link status down for %sinterface %s, disabling it in %d ms\n",
  					    (BOND_MODE(bond) ==
  					     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 */
  				bond_set_slave_link_state(slave, BOND_LINK_UP,
  							  BOND_SLAVE_NOTIFY_LATER);
  				slave->last_link_up = jiffies;
  				netdev_info(bond->dev, "link status up again after %d ms for interface %s\n",
  					    (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;
  
  			bond_set_slave_link_state(slave, BOND_LINK_BACK,
  						  BOND_SLAVE_NOTIFY_LATER);
  			slave->delay = bond->params.updelay;
  
  			if (slave->delay) {
  				netdev_info(bond->dev, "link status up for interface %s, enabling it in %d ms\n",
  					    slave->dev->name,
  					    ignore_updelay ? 0 :
  					    bond->params.updelay *
  					    bond->params.miimon);
  			}
  			/*FALLTHRU*/
  		case BOND_LINK_BACK:
  			if (!link_state) {
  				bond_set_slave_link_state(slave,
  							  BOND_LINK_DOWN,
  							  BOND_SLAVE_NOTIFY_LATER);
  				netdev_info(bond->dev, "link status down again after %d ms for interface %s\n",
  					    (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 list_head *iter;
  	struct slave *slave, *primary;
  
  	bond_for_each_slave(bond, slave, iter) {
  		switch (slave->new_link) {
  		case BOND_LINK_NOCHANGE:
  			continue;
  
  		case BOND_LINK_UP:
  			bond_update_speed_duplex(slave);
  			bond_set_slave_link_state(slave, BOND_LINK_UP,
  						  BOND_SLAVE_NOTIFY_NOW);
  			slave->last_link_up = jiffies;
  
  			primary = rtnl_dereference(bond->primary_slave);
  			if (BOND_MODE(bond) == BOND_MODE_8023AD) {
  				/* prevent it from being the active one */
  				bond_set_backup_slave(slave);
  			} else if (BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
  				/* make it immediately active */
  				bond_set_active_slave(slave);
  			} else if (slave != primary) {
  				/* prevent it from being the active one */
  				bond_set_backup_slave(slave);
  			}
  
  			netdev_info(bond->dev, "link status definitely up for interface %s, %u Mbps %s duplex\n",
  				    slave->dev->name,
  				    slave->speed == SPEED_UNKNOWN ? 0 : slave->speed,
  				    slave->duplex ? "full" : "half");
  
  			/* notify ad that the link status has changed */
  			if (BOND_MODE(bond) == 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_MODE(bond) == BOND_MODE_XOR)
  				bond_update_slave_arr(bond, NULL);
  
  			if (!bond->curr_active_slave || slave == primary)
  				goto do_failover;
  
  			continue;
  
  		case BOND_LINK_DOWN:
  			if (slave->link_failure_count < UINT_MAX)
  				slave->link_failure_count++;
  
  			bond_set_slave_link_state(slave, BOND_LINK_DOWN,
  						  BOND_SLAVE_NOTIFY_NOW);
  
  			if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP ||
  			    BOND_MODE(bond) == BOND_MODE_8023AD)
  				bond_set_slave_inactive_flags(slave,
  							      BOND_SLAVE_NOTIFY_NOW);
  
  			netdev_info(bond->dev, "link status definitely down for interface %s, disabling it\n",
  				    slave->dev->name);
  
  			if (BOND_MODE(bond) == 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 (BOND_MODE(bond) == BOND_MODE_XOR)
  				bond_update_slave_arr(bond, NULL);
  
  			if (slave == rcu_access_pointer(bond->curr_active_slave))
  				goto do_failover;
  
  			continue;
  
  		default:
  			netdev_err(bond->dev, "invalid new link %d on slave %s\n",
  				   slave->new_link, slave->dev->name);
  			slave->new_link = BOND_LINK_NOCHANGE;
  
  			continue;
  		}
  
  do_failover:
  		block_netpoll_tx();
  		bond_select_active_slave(bond);
  		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.
   */
  static 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;
  
  	delay = msecs_to_jiffies(bond->params.miimon);
  
  	if (!bond_has_slaves(bond))
  		goto re_arm;
  
  	rcu_read_lock();
  
  	should_notify_peers = bond_should_notify_peers(bond);
  
  	if (bond_miimon_inspect(bond)) {
  		rcu_read_unlock();
  
  		/* Race avoidance with bond_close cancel of workqueue */
  		if (!rtnl_trylock()) {
  			delay = 1;
  			should_notify_peers = false;
  			goto re_arm;
  		}
  
  		bond_miimon_commit(bond);
  
  		rtnl_unlock();	/* might sleep, hold no other locks */
  	} else
  		rcu_read_unlock();
  
  re_arm:
  	if (bond->params.miimon)
  		queue_delayed_work(bond->wq, &bond->mii_work, delay);
  
  	if (should_notify_peers) {
  		if (!rtnl_trylock())
  			return;
  		call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);
  		rtnl_unlock();
  	}
  }
  
  static bool bond_has_this_ip(struct bonding *bond, __be32 ip)
  {
  	struct net_device *upper;
  	struct list_head *iter;
  	bool ret = false;
  
  	if (ip == bond_confirm_addr(bond->dev, 0, ip))
  		return true;
  
  	rcu_read_lock();
  	netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
  		if (ip == bond_confirm_addr(upper, 0, ip)) {
  			ret = true;
  			break;
  		}
  	}
  	rcu_read_unlock();
  
  	return ret;
  }
  
  /* 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,
  			  struct bond_vlan_tag *tags)
  {
  	struct sk_buff *skb;
  	struct bond_vlan_tag *outer_tag = tags;
  
  	netdev_dbg(slave_dev, "arp %d on slave %s: dst %pI4 src %pI4\n",
  		   arp_op, slave_dev->name, &dest_ip, &src_ip);
  
  	skb = arp_create(arp_op, ETH_P_ARP, dest_ip, slave_dev, src_ip,
  			 NULL, slave_dev->dev_addr, NULL);
  
  	if (!skb) {
  		net_err_ratelimited("ARP packet allocation failed\n");
  		return;
  	}
  
  	if (!tags || tags->vlan_proto == VLAN_N_VID)
  		goto xmit;
  
  	tags++;
  
  	/* Go through all the tags backwards and add them to the packet */
  	while (tags->vlan_proto != VLAN_N_VID) {
  		if (!tags->vlan_id) {
  			tags++;
  			continue;
  		}
  
  		netdev_dbg(slave_dev, "inner tag: proto %X vid %X\n",
  			   ntohs(outer_tag->vlan_proto), tags->vlan_id);
  		skb = vlan_insert_tag_set_proto(skb, tags->vlan_proto,
  						tags->vlan_id);
  		if (!skb) {
  			net_err_ratelimited("failed to insert inner VLAN tag\n");
  			return;
  		}
  
  		tags++;
  	}
  	/* Set the outer tag */
  	if (outer_tag->vlan_id) {
  		netdev_dbg(slave_dev, "outer tag: proto %X vid %X\n",
  			   ntohs(outer_tag->vlan_proto), outer_tag->vlan_id);
  		__vlan_hwaccel_put_tag(skb, outer_tag->vlan_proto,
  				       outer_tag->vlan_id);
  	}
  
  xmit:
  	arp_xmit(skb);
  }
  
  /* Validate the device path between the @start_dev and the @end_dev.
   * The path is valid if the @end_dev is reachable through device
   * stacking.
   * When the path is validated, collect any vlan information in the
   * path.
   */
  struct bond_vlan_tag *bond_verify_device_path(struct net_device *start_dev,
  					      struct net_device *end_dev,
  					      int level)
  {
  	struct bond_vlan_tag *tags;
  	struct net_device *upper;
  	struct list_head  *iter;
  
  	if (start_dev == end_dev) {
  		tags = kzalloc(sizeof(*tags) * (level + 1), GFP_ATOMIC);
  		if (!tags)
  			return ERR_PTR(-ENOMEM);
  		tags[level].vlan_proto = VLAN_N_VID;
  		return tags;
  	}
  
  	netdev_for_each_upper_dev_rcu(start_dev, upper, iter) {
  		tags = bond_verify_device_path(upper, end_dev, level + 1);
  		if (IS_ERR_OR_NULL(tags)) {
  			if (IS_ERR(tags))
  				return tags;
  			continue;
  		}
  		if (is_vlan_dev(upper)) {
  			tags[level].vlan_proto = vlan_dev_vlan_proto(upper);
  			tags[level].vlan_id = vlan_dev_vlan_id(upper);
  		}
  
  		return tags;
  	}
  
  	return NULL;
  }
  
  static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
  {
  	struct rtable *rt;
  	struct bond_vlan_tag *tags;
  	__be32 *targets = bond->params.arp_targets, addr;
  	int i;
  
  	for (i = 0; i < BOND_MAX_ARP_TARGETS && targets[i]; i++) {
  		netdev_dbg(bond->dev, "basa: target %pI4\n", &targets[i]);
  		tags = NULL;
  
  		/* Find out through which dev should the packet go */
  		rt = ip_route_output(dev_net(bond->dev), targets[i], 0,
  				     RTO_ONLINK, 0);
  		if (IS_ERR(rt)) {
  			/* there's no route to target - try to send arp
  			 * probe to generate any traffic (arp_validate=0)
  			 */
  			if (bond->params.arp_validate)
  				net_warn_ratelimited("%s: no route to arp_ip_target %pI4 and arp_validate is set\n",
  						     bond->dev->name,
  						     &targets[i]);
  			bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
  				      0, tags);
  			continue;
  		}
  
  		/* bond device itself */
  		if (rt->dst.dev == bond->dev)
  			goto found;
  
  		rcu_read_lock();
  		tags = bond_verify_device_path(bond->dev, rt->dst.dev, 0);
  		rcu_read_unlock();
  
  		if (!IS_ERR_OR_NULL(tags))
  			goto found;
  
  		/* Not our device - skip */
  		netdev_dbg(bond->dev, "no path to arp_ip_target %pI4 via rt.dev %s\n",
  			   &targets[i], rt->dst.dev ? rt->dst.dev->name : "NULL");
  
  		ip_rt_put(rt);
  		continue;
  
  found:
  		addr = bond_confirm_addr(rt->dst.dev, targets[i], 0);
  		ip_rt_put(rt);
  		bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
  			      addr, tags);
  		kfree(tags);
  	}
  }
  
  static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32 sip, __be32 tip)
  {
  	int i;
  
  	if (!sip || !bond_has_this_ip(bond, tip)) {
  		netdev_dbg(bond->dev, "bva: sip %pI4 tip %pI4 not found\n",
  			   &sip, &tip);
  		return;
  	}
  
  	i = bond_get_targets_ip(bond->params.arp_targets, sip);
  	if (i == -1) {
  		netdev_dbg(bond->dev, "bva: sip %pI4 not found in targets\n",
  			   &sip);
  		return;
  	}
  	slave->last_rx = jiffies;
  	slave->target_last_arp_rx[i] = jiffies;
  }
  
  int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
  		 struct slave *slave)
  {
  	struct arphdr *arp = (struct arphdr *)skb->data;
  	struct slave *curr_active_slave, *curr_arp_slave;
  	unsigned char *arp_ptr;
  	__be32 sip, tip;
  	int alen, is_arp = skb->protocol == __cpu_to_be16(ETH_P_ARP);
  
  	if (!slave_do_arp_validate(bond, slave)) {
  		if ((slave_do_arp_validate_only(bond) && is_arp) ||
  		    !slave_do_arp_validate_only(bond))
  			slave->last_rx = jiffies;
  		return RX_HANDLER_ANOTHER;
  	} else if (!is_arp) {
  		return RX_HANDLER_ANOTHER;
  	}
  
  	alen = arp_hdr_len(bond->dev);
  
  	netdev_dbg(bond->dev, "bond_arp_rcv: skb->dev %s\n",
  		   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);
  
  	netdev_dbg(bond->dev, "bond_arp_rcv: %s/%d av %d sv %d sip %pI4 tip %pI4\n",
  		   slave->dev->name, bond_slave_state(slave),
  		     bond->params.arp_validate, slave_do_arp_validate(bond, slave),
  		     &sip, &tip);
  
  	curr_active_slave = rcu_dereference(bond->curr_active_slave);
  	curr_arp_slave = rcu_dereference(bond->current_arp_slave);
  
  	/* We 'trust' the received ARP enough to validate it if:
  	 *
  	 * (a) the slave receiving the ARP is active (which includes the
  	 * current ARP slave, if any), or
  	 *
  	 * (b) the receiving slave isn't active, but there is a currently
  	 * active slave and it received valid arp reply(s) after it became
  	 * the currently active slave, or
  	 *
  	 * (c) there is an ARP slave that sent an ARP during the prior ARP
  	 * interval, and we receive an ARP reply on any slave.  We accept
  	 * these because switch FDB update delays may deliver the ARP
  	 * reply to a slave other than the sender of the ARP request.
  	 *
  	 * Note: for (b), backup slaves are receiving the broadcast ARP
  	 * request, not a reply.  This request passes from the sending
  	 * slave through the L2 switch(es) to the receiving slave.  Since
  	 * this is checking the request, sip/tip are swapped for
  	 * validation.
  	 *
  	 * This is done to avoid endless looping when we can't reach the
  	 * arp_ip_target and fool ourselves with our own arp requests.
  	 */
  	if (bond_is_active_slave(slave))
  		bond_validate_arp(bond, slave, sip, tip);
  	else if (curr_active_slave &&
  		 time_after(slave_last_rx(bond, curr_active_slave),
  			    curr_active_slave->last_link_up))
  		bond_validate_arp(bond, slave, tip, sip);
  	else if (curr_arp_slave && (arp->ar_op == htons(ARPOP_REPLY)) &&
  		 bond_time_in_interval(bond,
  				       dev_trans_start(curr_arp_slave->dev), 1))
  		bond_validate_arp(bond, slave, sip, tip);
  
  out_unlock:
  	if (arp != (struct arphdr *)skb->data)
  		kfree(arp);
  	return RX_HANDLER_ANOTHER;
  }
  
  /* function to verify if we're in the arp_interval timeslice, returns true if
   * (last_act - arp_interval) <= jiffies <= (last_act + mod * arp_interval +
   * arp_interval/2) . the arp_interval/2 is needed for really fast networks.
   */
  static bool bond_time_in_interval(struct bonding *bond, unsigned long last_act,
  				  int mod)
  {
  	int delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
  
  	return time_in_range(jiffies,
  			     last_act - delta_in_ticks,
  			     last_act + mod * delta_in_ticks + delta_in_ticks/2);
  }
  
  /* This function is called regularly to monitor each slave's link
   * ensuring that traffic is being sent and received when arp monitoring
   * is used in load-balancing mode. if the adapter has been dormant, then an
   * arp is transmitted to generate traffic. see activebackup_arp_monitor for
   * arp monitoring in active backup mode.
   */
  static void bond_loadbalance_arp_mon(struct work_struct *work)
  {
  	struct bonding *bond = container_of(work, struct bonding,
  					    arp_work.work);
  	struct slave *slave, *oldcurrent;
  	struct list_head *iter;
  	int do_failover = 0, slave_state_changed = 0;
  
  	if (!bond_has_slaves(bond))
  		goto re_arm;
  
  	rcu_read_lock();
  
  	oldcurrent = rcu_dereference(bond->curr_active_slave);
  	/* 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->last_link_up 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_rcu(bond, slave, iter) {
  		unsigned long trans_start = dev_trans_start(slave->dev);
  
  		if (slave->link != BOND_LINK_UP) {
  			if (bond_time_in_interval(bond, trans_start, 1) &&
  			    bond_time_in_interval(bond, slave->last_rx, 1)) {
  
  				slave->link  = BOND_LINK_UP;
  				slave_state_changed = 1;
  
  				/* 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) {
  					netdev_info(bond->dev, "link status definitely up for interface %s\n",
  						    slave->dev->name);
  					do_failover = 1;
  				} else {
  					netdev_info(bond->dev, "interface %s is now up\n",
  						    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 (!bond_time_in_interval(bond, trans_start, 2) ||
  			    !bond_time_in_interval(bond, slave->last_rx, 2)) {
  
  				slave->link  = BOND_LINK_DOWN;
  				slave_state_changed = 1;
  
  				if (slave->link_failure_count < UINT_MAX)
  					slave->link_failure_count++;
  
  				netdev_info(bond->dev, "interface %s is now down\n",
  					    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 (bond_slave_is_up(slave))
  			bond_arp_send_all(bond, slave);
  	}
  
  	rcu_read_unlock();
  
  	if (do_failover || slave_state_changed) {
  		if (!rtnl_trylock())
  			goto re_arm;
  
  		if (slave_state_changed) {
  			bond_slave_state_change(bond);
  			if (BOND_MODE(bond) == BOND_MODE_XOR)
  				bond_update_slave_arr(bond, NULL);
  		}
  		if (do_failover) {
  			block_netpoll_tx();
  			bond_select_active_slave(bond);
  			unblock_netpoll_tx();
  		}
  		rtnl_unlock();
  	}
  
  re_arm:
  	if (bond->params.arp_interval)
  		queue_delayed_work(bond->wq, &bond->arp_work,
  				   msecs_to_jiffies(bond->params.arp_interval));
  }
  
  /* 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 rcu_read_lock held.
   */
  static int bond_ab_arp_inspect(struct bonding *bond)
  {
  	unsigned long trans_start, last_rx;
  	struct list_head *iter;
  	struct slave *slave;
  	int commit = 0;
  
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		slave->new_link = BOND_LINK_NOCHANGE;
  		last_rx = slave_last_rx(bond, slave);
  
  		if (slave->link != BOND_LINK_UP) {
  			if (bond_time_in_interval(bond, last_rx, 1)) {
  				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 (bond_time_in_interval(bond, slave->last_link_up, 2))
  			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) &&
  		    !rcu_access_pointer(bond->current_arp_slave) &&
  		    !bond_time_in_interval(bond, last_rx, 3)) {
  			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) &&
  		    (!bond_time_in_interval(bond, trans_start, 2) ||
  		     !bond_time_in_interval(bond, last_rx, 2))) {
  			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 hold.
   */
  static void bond_ab_arp_commit(struct bonding *bond)
  {
  	unsigned long trans_start;
  	struct list_head *iter;
  	struct slave *slave;
  
  	bond_for_each_slave(bond, slave, iter) {
  		switch (slave->new_link) {
  		case BOND_LINK_NOCHANGE:
  			continue;
  
  		case BOND_LINK_UP:
  			trans_start = dev_trans_start(slave->dev);
  			if (rtnl_dereference(bond->curr_active_slave) != slave ||
  			    (!rtnl_dereference(bond->curr_active_slave) &&
  			     bond_time_in_interval(bond, trans_start, 1))) {
  				struct slave *current_arp_slave;
  
  				current_arp_slave = rtnl_dereference(bond->current_arp_slave);
  				bond_set_slave_link_state(slave, BOND_LINK_UP,
  							  BOND_SLAVE_NOTIFY_NOW);
  				if (current_arp_slave) {
  					bond_set_slave_inactive_flags(
  						current_arp_slave,
  						BOND_SLAVE_NOTIFY_NOW);
  					RCU_INIT_POINTER(bond->current_arp_slave, NULL);
  				}
  
  				netdev_info(bond->dev, "link status definitely up for interface %s\n",
  					    slave->dev->name);
  
  				if (!rtnl_dereference(bond->curr_active_slave) ||
  				    slave == rtnl_dereference(bond->primary_slave))
  					goto do_failover;
  
  			}
  
  			continue;
  
  		case BOND_LINK_DOWN:
  			if (slave->link_failure_count < UINT_MAX)
  				slave->link_failure_count++;
  
  			bond_set_slave_link_state(slave, BOND_LINK_DOWN,
  						  BOND_SLAVE_NOTIFY_NOW);
  			bond_set_slave_inactive_flags(slave,
  						      BOND_SLAVE_NOTIFY_NOW);
  
  			netdev_info(bond->dev, "link status definitely down for interface %s, disabling it\n",
  				    slave->dev->name);
  
  			if (slave == rtnl_dereference(bond->curr_active_slave)) {
  				RCU_INIT_POINTER(bond->current_arp_slave, NULL);
  				goto do_failover;
  			}
  
  			continue;
  
  		default:
  			netdev_err(bond->dev, "impossible: new_link %d on slave %s\n",
  				   slave->new_link, slave->dev->name);
  			continue;
  		}
  
  do_failover:
  		block_netpoll_tx();
  		bond_select_active_slave(bond);
  		unblock_netpoll_tx();
  	}
  
  	bond_set_carrier(bond);
  }
  
  /* Send ARP probes for active-backup mode ARP monitor.
   *
   * Called with rcu_read_lock held.
   */
  static bool bond_ab_arp_probe(struct bonding *bond)
  {
  	struct slave *slave, *before = NULL, *new_slave = NULL,
  		     *curr_arp_slave = rcu_dereference(bond->current_arp_slave),
  		     *curr_active_slave = rcu_dereference(bond->curr_active_slave);
  	struct list_head *iter;
  	bool found = false;
  	bool should_notify_rtnl = BOND_SLAVE_NOTIFY_LATER;
  
  	if (curr_arp_slave && curr_active_slave)
  		netdev_info(bond->dev, "PROBE: c_arp %s && cas %s BAD\n",
  			    curr_arp_slave->dev->name,
  			    curr_active_slave->dev->name);
  
  	if (curr_active_slave) {
  		bond_arp_send_all(bond, curr_active_slave);
  		return should_notify_rtnl;
  	}
  
  	/* 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 (!curr_arp_slave) {
  		curr_arp_slave = bond_first_slave_rcu(bond);
  		if (!curr_arp_slave)
  			return should_notify_rtnl;
  	}
  
  	bond_set_slave_inactive_flags(curr_arp_slave, BOND_SLAVE_NOTIFY_LATER);
  
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		if (!found && !before && bond_slave_is_up(slave))
  			before = slave;
  
  		if (found && !new_slave && bond_slave_is_up(slave))
  			new_slave = slave;
  		/* 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 (!bond_slave_is_up(slave) && slave->link == BOND_LINK_UP) {
  			bond_set_slave_link_state(slave, BOND_LINK_DOWN,
  						  BOND_SLAVE_NOTIFY_LATER);
  			if (slave->link_failure_count < UINT_MAX)
  				slave->link_failure_count++;
  
  			bond_set_slave_inactive_flags(slave,
  						      BOND_SLAVE_NOTIFY_LATER);
  
  			netdev_info(bond->dev, "backup interface %s is now down\n",
  				    slave->dev->name);
  		}
  		if (slave == curr_arp_slave)
  			found = true;
  	}
  
  	if (!new_slave && before)
  		new_slave = before;
  
  	if (!new_slave)
  		goto check_state;
  
  	bond_set_slave_link_state(new_slave, BOND_LINK_BACK,
  				  BOND_SLAVE_NOTIFY_LATER);
  	bond_set_slave_active_flags(new_slave, BOND_SLAVE_NOTIFY_LATER);
  	bond_arp_send_all(bond, new_slave);
  	new_slave->last_link_up = jiffies;
  	rcu_assign_pointer(bond->current_arp_slave, new_slave);
  
  check_state:
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		if (slave->should_notify || slave->should_notify_link) {
  			should_notify_rtnl = BOND_SLAVE_NOTIFY_NOW;
  			break;
  		}
  	}
  	return should_notify_rtnl;
  }
  
  static 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;
  	bool should_notify_rtnl = false;
  	int delta_in_ticks;
  
  	delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
  
  	if (!bond_has_slaves(bond))
  		goto re_arm;
  
  	rcu_read_lock();
  
  	should_notify_peers = bond_should_notify_peers(bond);
  
  	if (bond_ab_arp_inspect(bond)) {
  		rcu_read_unlock();
  
  		/* Race avoidance with bond_close flush of workqueue */
  		if (!rtnl_trylock()) {
  			delta_in_ticks = 1;
  			should_notify_peers = false;
  			goto re_arm;
  		}
  
  		bond_ab_arp_commit(bond);
  
  		rtnl_unlock();
  		rcu_read_lock();
  	}
  
  	should_notify_rtnl = bond_ab_arp_probe(bond);
  	rcu_read_unlock();
  
  re_arm:
  	if (bond->params.arp_interval)
  		queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
  
  	if (should_notify_peers || should_notify_rtnl) {
  		if (!rtnl_trylock())
  			return;
  
  		if (should_notify_peers)
  			call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
  						 bond->dev);
  		if (should_notify_rtnl) {
  			bond_slave_state_notify(bond);
  			bond_slave_link_notify(bond);
  		}
  
  		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;
  	case NETDEV_NOTIFY_PEERS:
  		if (event_bond->send_peer_notif)
  			event_bond->send_peer_notif--;
  		break;
  	default:
  		break;
  	}
  
  	return NOTIFY_DONE;
  }
  
  static int bond_slave_netdev_event(unsigned long event,
  				   struct net_device *slave_dev)
  {
  	struct slave *slave = bond_slave_get_rtnl(slave_dev), *primary;
  	struct bonding *bond;
  	struct net_device *bond_dev;
  
  	/* A netdev event can be generated while enslaving a device
  	 * before netdev_rx_handler_register is called in which case
  	 * slave will be NULL
  	 */
  	if (!slave)
  		return NOTIFY_DONE;
  	bond_dev = slave->bond->dev;
  	bond = slave->bond;
  	primary = rtnl_dereference(bond->primary_slave);
  
  	switch (event) {
  	case NETDEV_UNREGISTER:
  		if (bond_dev->type != ARPHRD_ETHER)
  			bond_release_and_destroy(bond_dev, slave_dev);
  		else
  			bond_release(bond_dev, slave_dev);
  		break;
  	case NETDEV_UP:
  	case NETDEV_CHANGE:
  		bond_update_speed_duplex(slave);
  		if (BOND_MODE(bond) == BOND_MODE_8023AD)
  			bond_3ad_adapter_speed_duplex_changed(slave);
  		/* Fallthrough */
  	case NETDEV_DOWN:
  		/* Refresh slave-array if applicable!
  		 * If the setup does not use miimon or arpmon (mode-specific!),
  		 * then these events will not cause the slave-array to be
  		 * refreshed. This will cause xmit to use a slave that is not
  		 * usable. Avoid such situation by refeshing the array at these
  		 * events. If these (miimon/arpmon) parameters are configured
  		 * then array gets refreshed twice and that should be fine!
  		 */
  		if (bond_mode_uses_xmit_hash(bond))
  			bond_update_slave_arr(bond, NULL);
  		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:
  		/* we don't care if we don't have primary set */
  		if (!bond_uses_primary(bond) ||
  		    !bond->params.primary[0])
  			break;
  
  		if (slave == primary) {
  			/* slave's name changed - he's no longer primary */
  			RCU_INIT_POINTER(bond->primary_slave, NULL);
  		} else if (!strcmp(slave_dev->name, bond->params.primary)) {
  			/* we have a new primary slave */
  			rcu_assign_pointer(bond->primary_slave, slave);
  		} else { /* we didn't change primary - exit */
  			break;
  		}
  
  		netdev_info(bond->dev, "Primary slave changed to %s, reselecting active slave\n",
  			    primary ? slave_dev->name : "none");
  
  		block_netpoll_tx();
  		bond_select_active_slave(bond);
  		unblock_netpoll_tx();
  		break;
  	case NETDEV_FEAT_CHANGE:
  		bond_compute_features(bond);
  		break;
  	case NETDEV_RESEND_IGMP:
  		/* Propagate to master device */
  		call_netdevice_notifiers(event, slave->bond->dev);
  		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 = netdev_notifier_info_to_dev(ptr);
  
  	netdev_dbg(event_dev, "event: %lx\n", event);
  
  	if (!(event_dev->priv_flags & IFF_BONDING))
  		return NOTIFY_DONE;
  
  	if (event_dev->flags & IFF_MASTER) {
  		netdev_dbg(event_dev, "IFF_MASTER\n");
  		return bond_master_netdev_event(event, event_dev);
  	}
  
  	if (event_dev->flags & IFF_SLAVE) {
  		netdev_dbg(event_dev, "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 -----------------------------*/
  
  /* L2 hash helper */
  static inline u32 bond_eth_hash(struct sk_buff *skb)
  {
  	struct ethhdr *ep, hdr_tmp;
  
  	ep = skb_header_pointer(skb, 0, sizeof(hdr_tmp), &hdr_tmp);
  	if (ep)
  		return ep->h_dest[5] ^ ep->h_source[5] ^ ep->h_proto;
  	return 0;
  }
  
  /* Extract the appropriate headers based on bond's xmit policy */
  static bool bond_flow_dissect(struct bonding *bond, struct sk_buff *skb,
  			      struct flow_keys *fk)
  {
  	const struct ipv6hdr *iph6;
  	const struct iphdr *iph;
  	int noff, proto = -1;
  
  	if (bond->params.xmit_policy > BOND_XMIT_POLICY_LAYER23)
  		return skb_flow_dissect_flow_keys(skb, fk, 0);
  
  	fk->ports.ports = 0;
  	noff = skb_network_offset(skb);
  	if (skb->protocol == htons(ETH_P_IP)) {
  		if (unlikely(!pskb_may_pull(skb, noff + sizeof(*iph))))
  			return false;
  		iph = ip_hdr(skb);
  		iph_to_flow_copy_v4addrs(fk, iph);
  		noff += iph->ihl << 2;
  		if (!ip_is_fragment(iph))
  			proto = iph->protocol;
  	} else if (skb->protocol == htons(ETH_P_IPV6)) {
  		if (unlikely(!pskb_may_pull(skb, noff + sizeof(*iph6))))
  			return false;
  		iph6 = ipv6_hdr(skb);
  		iph_to_flow_copy_v6addrs(fk, iph6);
  		noff += sizeof(*iph6);
  		proto = iph6->nexthdr;
  	} else {
  		return false;
  	}
  	if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER34 && proto >= 0)
  		fk->ports.ports = skb_flow_get_ports(skb, noff, proto);
  
  	return true;
  }
  
  /**
   * bond_xmit_hash - generate a hash value based on the xmit policy
   * @bond: bonding device
   * @skb: buffer to use for headers
   *
   * This function will extract the necessary headers from the skb buffer and use
   * them to generate a hash based on the xmit_policy set in the bonding device
   */
  u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb)
  {
  	struct flow_keys flow;
  	u32 hash;
  
  	if (bond->params.xmit_policy == BOND_XMIT_POLICY_ENCAP34 &&
  	    skb->l4_hash)
  		return skb->hash;
  
  	if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER2 ||
  	    !bond_flow_dissect(bond, skb, &flow))
  		return bond_eth_hash(skb);
  
  	if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER23 ||
  	    bond->params.xmit_policy == BOND_XMIT_POLICY_ENCAP23)
  		hash = bond_eth_hash(skb);
  	else
  		hash = (__force u32)flow.ports.ports;
  	hash ^= (__force u32)flow_get_u32_dst(&flow) ^
  		(__force u32)flow_get_u32_src(&flow);
  	hash ^= (hash >> 16);
  	hash ^= (hash >> 8);
  
  	return hash;
  }
  
  /*-------------------------- 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_MODE(bond) == 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);
  	INIT_DELAYED_WORK(&bond->slave_arr_work, bond_slave_arr_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);
  	cancel_delayed_work_sync(&bond->slave_arr_work);
  }
  
  static int bond_open(struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct list_head *iter;
  	struct slave *slave;
  
  	/* reset slave->backup and slave->inactive */
  	if (bond_has_slaves(bond)) {
  		bond_for_each_slave(bond, slave, iter) {
  			if (bond_uses_primary(bond) &&
  			    slave != rcu_access_pointer(bond->curr_active_slave)) {
  				bond_set_slave_inactive_flags(slave,
  							      BOND_SLAVE_NOTIFY_NOW);
  			} else if (BOND_MODE(bond) != BOND_MODE_8023AD) {
  				bond_set_slave_active_flags(slave,
  							    BOND_SLAVE_NOTIFY_NOW);
  			}
  		}
  	}
  
  	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_MODE(bond) == BOND_MODE_ALB)))
  			return -ENOMEM;
  		if (bond->params.tlb_dynamic_lb)
  			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);
  		bond->recv_probe = bond_arp_rcv;
  	}
  
  	if (BOND_MODE(bond) == 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);
  	}
  
  	if (bond_mode_uses_xmit_hash(bond))
  		bond_update_slave_arr(bond, NULL);
  
  	return 0;
  }
  
  static int bond_close(struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  
  	bond_work_cancel_all(bond);
  	bond->send_peer_notif = 0;
  	if (bond_is_lb(bond))
  		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 list_head *iter;
  	struct slave *slave;
  
  	memcpy(stats, &bond->bond_stats, sizeof(*stats));
  
  	bond_for_each_slave(bond, slave, iter) {
  		const struct rtnl_link_stats64 *sstats =
  			dev_get_stats(slave->dev, &temp);
  		struct rtnl_link_stats64 *pstats = &slave->slave_stats;
  
  		stats->rx_packets +=  sstats->rx_packets - pstats->rx_packets;
  		stats->rx_bytes += sstats->rx_bytes - pstats->rx_bytes;
  		stats->rx_errors += sstats->rx_errors - pstats->rx_errors;
  		stats->rx_dropped += sstats->rx_dropped - pstats->rx_dropped;
  
  		stats->tx_packets += sstats->tx_packets - pstats->tx_packets;;
  		stats->tx_bytes += sstats->tx_bytes - pstats->tx_bytes;
  		stats->tx_errors += sstats->tx_errors - pstats->tx_errors;
  		stats->tx_dropped += sstats->tx_dropped - pstats->tx_dropped;
  
  		stats->multicast += sstats->multicast - pstats->multicast;
  		stats->collisions += sstats->collisions - pstats->collisions;
  
  		stats->rx_length_errors += sstats->rx_length_errors - pstats->rx_length_errors;
  		stats->rx_over_errors += sstats->rx_over_errors - pstats->rx_over_errors;
  		stats->rx_crc_errors += sstats->rx_crc_errors - pstats->rx_crc_errors;
  		stats->rx_frame_errors += sstats->rx_frame_errors - pstats->rx_frame_errors;
  		stats->rx_fifo_errors += sstats->rx_fifo_errors - pstats->rx_fifo_errors;
  		stats->rx_missed_errors += sstats->rx_missed_errors - pstats->rx_missed_errors;
  
  		stats->tx_aborted_errors += sstats->tx_aborted_errors - pstats->tx_aborted_errors;
  		stats->tx_carrier_errors += sstats->tx_carrier_errors - pstats->tx_carrier_errors;
  		stats->tx_fifo_errors += sstats->tx_fifo_errors - pstats->tx_fifo_errors;
  		stats->tx_heartbeat_errors += sstats->tx_heartbeat_errors - pstats->tx_heartbeat_errors;
  		stats->tx_window_errors += sstats->tx_window_errors - pstats->tx_window_errors;
  
  		/* save off the slave stats for the next run */
  		memcpy(pstats, sstats, sizeof(*sstats));
  	}
  	memcpy(&bond->bond_stats, stats, sizeof(*stats));
  
  	return stats;
  }
  
  static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	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;
  	struct bond_opt_value newval;
  	struct net *net;
  	int res = 0;
  
  	netdev_dbg(bond_dev, "bond_ioctl: cmd=%d\n", 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) {
  			mii->val_out = 0;
  			if (netif_carrier_ok(bond->dev))
  				mii->val_out = BMSR_LSTATUS;
  		}
  
  		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:
  		break;
  	}
  
  	net = dev_net(bond_dev);
  
  	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
  		return -EPERM;
  
  	slave_dev = __dev_get_by_name(net, ifr->ifr_slave);
  
  	netdev_dbg(bond_dev, "slave_dev=%p:\n", slave_dev);
  
  	if (!slave_dev)
  		return -ENODEV;
  
  	netdev_dbg(bond_dev, "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:
  		bond_set_dev_addr(bond_dev, slave_dev);
  		res = 0;
  		break;
  	case BOND_CHANGE_ACTIVE_OLD:
  	case SIOCBONDCHANGEACTIVE:
  		bond_opt_initstr(&newval, slave_dev->name);
  		res = __bond_opt_set(bond, BOND_OPT_ACTIVE_SLAVE, &newval);
  		break;
  	default:
  		res = -EOPNOTSUPP;
  	}
  
  	return res;
  }
  
  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_rx_mode(struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct list_head *iter;
  	struct slave *slave;
  
  	rcu_read_lock();
  	if (bond_uses_primary(bond)) {
  		slave = rcu_dereference(bond->curr_active_slave);
  		if (slave) {
  			dev_uc_sync(slave->dev, bond_dev);
  			dev_mc_sync(slave->dev, bond_dev);
  		}
  	} else {
  		bond_for_each_slave_rcu(bond, slave, iter) {
  			dev_uc_sync_multiple(slave->dev, bond_dev);
  			dev_mc_sync_multiple(slave->dev, bond_dev);
  		}
  	}
  	rcu_read_unlock();
  }
  
  static int bond_neigh_init(struct neighbour *n)
  {
  	struct bonding *bond = netdev_priv(n->dev);
  	const struct net_device_ops *slave_ops;
  	struct neigh_parms parms;
  	struct slave *slave;
  	int ret;
  
  	slave = bond_first_slave(bond);
  	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.
   *
   * It's also called by master devices (such as vlans) to setup their
   * underlying devices. In that case - do nothing, we're already set up from
   * our init.
   */
  static int bond_neigh_setup(struct net_device *dev,
  			    struct neigh_parms *parms)
  {
  	/* modify only our neigh_parms */
  	if (parms->dev == dev)
  		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, *rollback_slave;
  	struct list_head *iter;
  	int res = 0;
  
  	netdev_dbg(bond_dev, "bond=%p, new_mtu=%d\n", bond, new_mtu);
  
  	bond_for_each_slave(bond, slave, iter) {
  		netdev_dbg(bond_dev, "s %p c_m %p\n",
  			   slave, 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.
  			 */
  			netdev_dbg(bond_dev, "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 */
  	bond_for_each_slave(bond, rollback_slave, iter) {
  		int tmp_res;
  
  		if (rollback_slave == slave)
  			break;
  
  		tmp_res = dev_set_mtu(rollback_slave->dev, bond_dev->mtu);
  		if (tmp_res) {
  			netdev_dbg(bond_dev, "unwind err %d dev %s\n",
  				   tmp_res, rollback_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 slave *slave, *rollback_slave;
  	struct sockaddr *sa = addr, tmp_sa;
  	struct list_head *iter;
  	int res = 0;
  
  	if (BOND_MODE(bond) == BOND_MODE_ALB)
  		return bond_alb_set_mac_address(bond_dev, addr);
  
  
  	netdev_dbg(bond_dev, "bond=%p\n", bond);
  
  	/* If fail_over_mac is enabled, do nothing and return success.
  	 * Returning an error causes ifenslave to fail.
  	 */
  	if (bond->params.fail_over_mac &&
  	    BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP)
  		return 0;
  
  	if (!is_valid_ether_addr(sa->sa_data))
  		return -EADDRNOTAVAIL;
  
  	bond_for_each_slave(bond, slave, iter) {
  		netdev_dbg(bond_dev, "slave %p %s\n", slave, slave->dev->name);
  		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...
  			 */
  			netdev_dbg(bond_dev, "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 */
  	bond_for_each_slave(bond, rollback_slave, iter) {
  		int tmp_res;
  
  		if (rollback_slave == slave)
  			break;
  
  		tmp_res = dev_set_mac_address(rollback_slave->dev, &tmp_sa);
  		if (tmp_res) {
  			netdev_dbg(bond_dev, "unwind err %d dev %s\n",
  				   tmp_res, rollback_slave->dev->name);
  		}
  	}
  
  	return res;
  }
  
  /**
   * bond_xmit_slave_id - transmit skb through slave with slave_id
   * @bond: bonding device that is transmitting
   * @skb: buffer to transmit
   * @slave_id: slave id up to slave_cnt-1 through which to transmit
   *
   * This function tries to transmit through slave with slave_id but in case
   * it fails, it tries to find the first available slave for transmission.
   * The skb is consumed in all cases, thus the function is void.
   */
  static void bond_xmit_slave_id(struct bonding *bond, struct sk_buff *skb, int slave_id)
  {
  	struct list_head *iter;
  	struct slave *slave;
  	int i = slave_id;
  
  	/* Here we start from the slave with slave_id */
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		if (--i < 0) {
  			if (bond_slave_can_tx(slave)) {
  				bond_dev_queue_xmit(bond, skb, slave->dev);
  				return;
  			}
  		}
  	}
  
  	/* Here we start from the first slave up to slave_id */
  	i = slave_id;
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		if (--i < 0)
  			break;
  		if (bond_slave_can_tx(slave)) {
  			bond_dev_queue_xmit(bond, skb, slave->dev);
  			return;
  		}
  	}
  	/* no slave that can tx has been found */
  	bond_tx_drop(bond->dev, skb);
  }
  
  /**
   * bond_rr_gen_slave_id - generate slave id based on packets_per_slave
   * @bond: bonding device to use
   *
   * Based on the value of the bonding device's packets_per_slave parameter
   * this function generates a slave id, which is usually used as the next
   * slave to transmit through.
   */
  static u32 bond_rr_gen_slave_id(struct bonding *bond)
  {
  	u32 slave_id;
  	struct reciprocal_value reciprocal_packets_per_slave;
  	int packets_per_slave = bond->params.packets_per_slave;
  
  	switch (packets_per_slave) {
  	case 0:
  		slave_id = prandom_u32();
  		break;
  	case 1:
  		slave_id = bond->rr_tx_counter;
  		break;
  	default:
  		reciprocal_packets_per_slave =
  			bond->params.reciprocal_packets_per_slave;
  		slave_id = reciprocal_divide(bond->rr_tx_counter,
  					     reciprocal_packets_per_slave);
  		break;
  	}
  	bond->rr_tx_counter++;
  
  	return slave_id;
  }
  
  static int bond_xmit_roundrobin(struct sk_buff *skb, struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	struct iphdr *iph = ip_hdr(skb);
  	struct slave *slave;
  	u32 slave_id;
  
  	/* 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)) {
  		slave = rcu_dereference(bond->curr_active_slave);
  		if (slave)
  			bond_dev_queue_xmit(bond, skb, slave->dev);
  		else
  			bond_xmit_slave_id(bond, skb, 0);
  	} else {
  		int slave_cnt = ACCESS_ONCE(bond->slave_cnt);
  
  		if (likely(slave_cnt)) {
  			slave_id = bond_rr_gen_slave_id(bond);
  			bond_xmit_slave_id(bond, skb, slave_id % slave_cnt);
  		} else {
  			bond_tx_drop(bond_dev, 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);
  	struct slave *slave;
  
  	slave = rcu_dereference(bond->curr_active_slave);
  	if (slave)
  		bond_dev_queue_xmit(bond, skb, slave->dev);
  	else
  		bond_tx_drop(bond_dev, skb);
  
  	return NETDEV_TX_OK;
  }
  
  /* Use this to update slave_array when (a) it's not appropriate to update
   * slave_array right away (note that update_slave_array() may sleep)
   * and / or (b) RTNL is not held.
   */
  void bond_slave_arr_work_rearm(struct bonding *bond, unsigned long delay)
  {
  	queue_delayed_work(bond->wq, &bond->slave_arr_work, delay);
  }
  
  /* Slave array work handler. Holds only RTNL */
  static void bond_slave_arr_handler(struct work_struct *work)
  {
  	struct bonding *bond = container_of(work, struct bonding,
  					    slave_arr_work.work);
  	int ret;
  
  	if (!rtnl_trylock())
  		goto err;
  
  	ret = bond_update_slave_arr(bond, NULL);
  	rtnl_unlock();
  	if (ret) {
  		pr_warn_ratelimited("Failed to update slave array from WT\n");
  		goto err;
  	}
  	return;
  
  err:
  	bond_slave_arr_work_rearm(bond, 1);
  }
  
  /* Build the usable slaves array in control path for modes that use xmit-hash
   * to determine the slave interface -
   * (a) BOND_MODE_8023AD
   * (b) BOND_MODE_XOR
   * (c) BOND_MODE_TLB && tlb_dynamic_lb == 0
   *
   * The caller is expected to hold RTNL only and NO other lock!
   */
  int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave)
  {
  	struct slave *slave;
  	struct list_head *iter;
  	struct bond_up_slave *new_arr, *old_arr;
  	int agg_id = 0;
  	int ret = 0;
  
  #ifdef CONFIG_LOCKDEP
  	WARN_ON(lockdep_is_held(&bond->mode_lock));
  #endif
  
  	new_arr = kzalloc(offsetof(struct bond_up_slave, arr[bond->slave_cnt]),
  			  GFP_KERNEL);
  	if (!new_arr) {
  		ret = -ENOMEM;
  		pr_err("Failed to build slave-array.\n");
  		goto out;
  	}
  	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
  		struct ad_info ad_info;
  
  		if (bond_3ad_get_active_agg_info(bond, &ad_info)) {
  			pr_debug("bond_3ad_get_active_agg_info failed\n");
  			kfree_rcu(new_arr, rcu);
  			/* No active aggragator means it's not safe to use
  			 * the previous array.
  			 */
  			old_arr = rtnl_dereference(bond->slave_arr);
  			if (old_arr) {
  				RCU_INIT_POINTER(bond->slave_arr, NULL);
  				kfree_rcu(old_arr, rcu);
  			}
  			goto out;
  		}
  		agg_id = ad_info.aggregator_id;
  	}
  	bond_for_each_slave(bond, slave, iter) {
  		if (BOND_MODE(bond) == BOND_MODE_8023AD) {
  			struct aggregator *agg;
  
  			agg = SLAVE_AD_INFO(slave)->port.aggregator;
  			if (!agg || agg->aggregator_identifier != agg_id)
  				continue;
  		}
  		if (!bond_slave_can_tx(slave))
  			continue;
  		if (skipslave == slave)
  			continue;
  		new_arr->arr[new_arr->count++] = slave;
  	}
  
  	old_arr = rtnl_dereference(bond->slave_arr);
  	rcu_assign_pointer(bond->slave_arr, new_arr);
  	if (old_arr)
  		kfree_rcu(old_arr, rcu);
  out:
  	if (ret != 0 && skipslave) {
  		int idx;
  
  		/* Rare situation where caller has asked to skip a specific
  		 * slave but allocation failed (most likely!). BTW this is
  		 * only possible when the call is initiated from
  		 * __bond_release_one(). In this situation; overwrite the
  		 * skipslave entry in the array with the last entry from the
  		 * array to avoid a situation where the xmit path may choose
  		 * this to-be-skipped slave to send a packet out.
  		 */
  		old_arr = rtnl_dereference(bond->slave_arr);
  		for (idx = 0; idx < old_arr->count; idx++) {
  			if (skipslave == old_arr->arr[idx]) {
  				old_arr->arr[idx] =
  				    old_arr->arr[old_arr->count-1];
  				old_arr->count--;
  				break;
  			}
  		}
  	}
  	return ret;
  }
  
  /* Use this Xmit function for 3AD as well as XOR modes. The current
   * usable slave array is formed in the control path. The xmit function
   * just calculates hash and sends the packet out.
   */
  static int bond_3ad_xor_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	struct bonding *bond = netdev_priv(dev);
  	struct slave *slave;
  	struct bond_up_slave *slaves;
  	unsigned int count;
  
  	slaves = rcu_dereference(bond->slave_arr);
  	count = slaves ? ACCESS_ONCE(slaves->count) : 0;
  	if (likely(count)) {
  		slave = slaves->arr[bond_xmit_hash(bond, skb) % count];
  		bond_dev_queue_xmit(bond, skb, slave->dev);
  	} else {
  		bond_tx_drop(dev, 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 = NULL;
  	struct list_head *iter;
  
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		if (bond_is_last_slave(bond, slave))
  			break;
  		if (bond_slave_is_up(slave) && slave->link == BOND_LINK_UP) {
  			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
  
  			if (!skb2) {
  				net_err_ratelimited("%s: Error: %s: skb_clone() failed\n",
  						    bond_dev->name, __func__);
  				continue;
  			}
  			bond_dev_queue_xmit(bond, skb2, slave->dev);
  		}
  	}
  	if (slave && bond_slave_is_up(slave) && slave->link == BOND_LINK_UP)
  		bond_dev_queue_xmit(bond, skb, slave->dev);
  	else
  		bond_tx_drop(bond_dev, skb);
  
  	return NETDEV_TX_OK;
  }
  
  /*------------------------- Device initialization ---------------------------*/
  
  /* Lookup the slave that corresponds to a qid */
  static inline int bond_slave_override(struct bonding *bond,
  				      struct sk_buff *skb)
  {
  	struct slave *slave = NULL;
  	struct list_head *iter;
  
  	if (!skb->queue_mapping)
  		return 1;
  
  	/* Find out if any slaves have the same mapping as this skb. */
  	bond_for_each_slave_rcu(bond, slave, iter) {
  		if (slave->queue_id == skb->queue_mapping) {
  			if (bond_slave_is_up(slave) &&
  			    slave->link == BOND_LINK_UP) {
  				bond_dev_queue_xmit(bond, skb, slave->dev);
  				return 0;
  			}
  			/* If the slave isn't UP, use default transmit policy. */
  			break;
  		}
  	}
  
  	return 1;
  }
  
  
  static u16 bond_select_queue(struct net_device *dev, struct sk_buff *skb,
  			     void *accel_priv, select_queue_fallback_t fallback)
  {
  	/* 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 (bond_should_override_tx_queue(bond) &&
  	    !bond_slave_override(bond, skb))
  		return NETDEV_TX_OK;
  
  	switch (BOND_MODE(bond)) {
  	case BOND_MODE_ROUNDROBIN:
  		return bond_xmit_roundrobin(skb, dev);
  	case BOND_MODE_ACTIVEBACKUP:
  		return bond_xmit_activebackup(skb, dev);
  	case BOND_MODE_8023AD:
  	case BOND_MODE_XOR:
  		return bond_3ad_xor_xmit(skb, dev);
  	case BOND_MODE_BROADCAST:
  		return bond_xmit_broadcast(skb, dev);
  	case BOND_MODE_ALB:
  		return bond_alb_xmit(skb, dev);
  	case BOND_MODE_TLB:
  		return bond_tlb_xmit(skb, dev);
  	default:
  		/* Should never happen, mode already checked */
  		netdev_err(dev, "Unknown bonding mode %d\n", BOND_MODE(bond));
  		WARN_ON_ONCE(1);
  		bond_tx_drop(dev, 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 (unlikely(is_netpoll_tx_blocked(dev)))
  		return NETDEV_TX_BUSY;
  
  	rcu_read_lock();
  	if (bond_has_slaves(bond))
  		ret = __bond_start_xmit(skb, dev);
  	else
  		bond_tx_drop(dev, skb);
  	rcu_read_unlock();
  
  	return ret;
  }
  
  static int bond_ethtool_get_settings(struct net_device *bond_dev,
  				     struct ethtool_cmd *ecmd)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  	unsigned long speed = 0;
  	struct list_head *iter;
  	struct slave *slave;
  
  	ecmd->duplex = DUPLEX_UNKNOWN;
  	ecmd->port = PORT_OTHER;
  
  	/* Since bond_slave_can_tx returns false for all inactive or down slaves, we
  	 * do not need to check mode.  Though link speed might not represent
  	 * the true receive or transmit bandwidth (not all modes are symmetric)
  	 * this is an accurate maximum.
  	 */
  	bond_for_each_slave(bond, slave, iter) {
  		if (bond_slave_can_tx(slave)) {
  			if (slave->speed != SPEED_UNKNOWN)
  				speed += slave->speed;
  			if (ecmd->duplex == DUPLEX_UNKNOWN &&
  			    slave->duplex != DUPLEX_UNKNOWN)
  				ecmd->duplex = slave->duplex;
  		}
  	}
  	ethtool_cmd_speed_set(ecmd, speed ? : SPEED_UNKNOWN);
  
  	return 0;
  }
  
  static void bond_ethtool_get_drvinfo(struct net_device *bond_dev,
  				     struct ethtool_drvinfo *drvinfo)
  {
  	strlcpy(drvinfo->driver, DRV_NAME, sizeof(drvinfo->driver));
  	strlcpy(drvinfo->version, DRV_VERSION, sizeof(drvinfo->version));
  	snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version), "%d",
  		 BOND_ABI_VERSION);
  }
  
  static const struct ethtool_ops bond_ethtool_ops = {
  	.get_drvinfo		= bond_ethtool_get_drvinfo,
  	.get_settings		= bond_ethtool_get_settings,
  	.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_rx_mode,
  	.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,
  	.ndo_bridge_setlink	= switchdev_port_bridge_setlink,
  	.ndo_bridge_getlink	= switchdev_port_bridge_getlink,
  	.ndo_bridge_dellink	= switchdev_port_bridge_dellink,
  	.ndo_fdb_add		= switchdev_port_fdb_add,
  	.ndo_fdb_del		= switchdev_port_fdb_del,
  	.ndo_fdb_dump		= switchdev_port_fdb_dump,
  	.ndo_features_check	= passthru_features_check,
  };
  
  static const struct device_type bond_type = {
  	.name = "bond",
  };
  
  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);
  }
  
  void bond_setup(struct net_device *bond_dev)
  {
  	struct bonding *bond = netdev_priv(bond_dev);
  
  	spin_lock_init(&bond->mode_lock);
  	bond->params = bonding_defaults;
  
  	/* Initialize pointers */
  	bond->dev = bond_dev;
  
  	/* Initialize the device entry points */
  	ether_setup(bond_dev);
  	bond_dev->netdev_ops = &bond_netdev_ops;
  	bond_dev->ethtool_ops = &bond_ethtool_ops;
  
  	bond_dev->destructor = bond_destructor;
  
  	SET_NETDEV_DEVTYPE(bond_dev, &bond_type);
  
  	/* Initialize the device options */
  	bond_dev->flags |= IFF_MASTER|IFF_MULTICAST;
  	bond_dev->priv_flags |= IFF_BONDING | IFF_UNICAST_FLT | IFF_NO_QUEUE;
  	bond_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
  
  	/* 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
  	 */
  
  	/* Don't allow bond devices to change network namespaces. */
  	bond_dev->features |= NETIF_F_NETNS_LOCAL;
  
  	bond_dev->hw_features = BOND_VLAN_FEATURES |
  				NETIF_F_HW_VLAN_CTAG_TX |
  				NETIF_F_HW_VLAN_CTAG_RX |
  				NETIF_F_HW_VLAN_CTAG_FILTER;
  
  	bond_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL;
  	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 list_head *iter;
  	struct slave *slave;
  	struct bond_up_slave *arr;
  
  	bond_netpoll_cleanup(bond_dev);
  
  	/* Release the bonded slaves */
  	bond_for_each_slave(bond, slave, iter)
  		__bond_release_one(bond_dev, slave->dev, true);
  	netdev_info(bond_dev, "Released all slaves\n");
  
  	arr = rtnl_dereference(bond->slave_arr);
  	if (arr) {
  		RCU_INIT_POINTER(bond->slave_arr, NULL);
  		kfree_rcu(arr, rcu);
  	}
  
  	list_del(&bond->bond_list);
  
  	bond_debug_unregister(bond);
  }
  
  /*------------------------- Module initialization ---------------------------*/
  
  static int bond_check_params(struct bond_params *params)
  {
  	int arp_validate_value, fail_over_mac_value, primary_reselect_value, i;
  	struct bond_opt_value newval;
  	const struct bond_opt_value *valptr;
  	int arp_all_targets_value;
  	u16 ad_actor_sys_prio = 0;
  	u16 ad_user_port_key = 0;
  
  	/* Convert string parameters. */
  	if (mode) {
  		bond_opt_initstr(&newval, mode);
  		valptr = bond_opt_parse(bond_opt_get(BOND_OPT_MODE), &newval);
  		if (!valptr) {
  			pr_err("Error: Invalid bonding mode \"%s\"\n", mode);
  			return -EINVAL;
  		}
  		bond_mode = valptr->value;
  	}
  
  	if (xmit_hash_policy) {
  		if ((bond_mode != BOND_MODE_XOR) &&
  		    (bond_mode != BOND_MODE_8023AD) &&
  		    (bond_mode != BOND_MODE_TLB)) {
  			pr_info("xmit_hash_policy param is irrelevant in mode %s\n",
  				bond_mode_name(bond_mode));
  		} else {
  			bond_opt_initstr(&newval, xmit_hash_policy);
  			valptr = bond_opt_parse(bond_opt_get(BOND_OPT_XMIT_HASH),
  						&newval);
  			if (!valptr) {
  				pr_err("Error: Invalid xmit_hash_policy \"%s\"\n",
  				       xmit_hash_policy);
  				return -EINVAL;
  			}
  			xmit_hashtype = valptr->value;
  		}
  	}
  
  	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 {
  			bond_opt_initstr(&newval, lacp_rate);
  			valptr = bond_opt_parse(bond_opt_get(BOND_OPT_LACP_RATE),
  						&newval);
  			if (!valptr) {
  				pr_err("Error: Invalid lacp rate \"%s\"\n",
  				       lacp_rate);
  				return -EINVAL;
  			}
  			lacp_fast = valptr->value;
  		}
  	}
  
  	if (ad_select) {
  		bond_opt_initstr(&newval, ad_select);
  		valptr = bond_opt_parse(bond_opt_get(BOND_OPT_AD_SELECT),
  					&newval);
  		if (!valptr) {
  			pr_err("Error: Invalid ad_select \"%s\"\n", ad_select);
  			return -EINVAL;
  		}
  		params->ad_select = valptr->value;
  		if (bond_mode != BOND_MODE_8023AD)
  			pr_warn("ad_select param only affects 802.3ad mode\n");
  	} else {
  		params->ad_select = BOND_AD_STABLE;
  	}
  
  	if (max_bonds < 0) {
  		pr_warn("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_warn("Warning: miimon module parameter (%d), not in range 0-%d, so it was reset to 0\n",
  			miimon, INT_MAX);
  		miimon = 0;
  	}
  
  	if (updelay < 0) {
  		pr_warn("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_warn("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_warn("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_warn("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/TLB/ALB */
  	if (!bond_mode_uses_arp(bond_mode)) {
  		if (!miimon) {
  			pr_warn("Warning: miimon must be specified, otherwise bonding will not detect link failure, speed and duplex which are essential for 802.3ad operation\n");
  			pr_warn("Forcing miimon to 100msec\n");
  			miimon = BOND_DEFAULT_MIIMON;
  		}
  	}
  
  	if (tx_queues < 1 || tx_queues > 255) {
  		pr_warn("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_warn("Warning: all_slaves_active module parameter (%d), not of valid value (0/1), so it was set to 0\n",
  			all_slaves_active);
  		all_slaves_active = 0;
  	}
  
  	if (resend_igmp < 0 || resend_igmp > 255) {
  		pr_warn("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;
  	}
  
  	bond_opt_initval(&newval, packets_per_slave);
  	if (!bond_opt_parse(bond_opt_get(BOND_OPT_PACKETS_PER_SLAVE), &newval)) {
  		pr_warn("Warning: packets_per_slave (%d) should be between 0 and %u resetting to 1\n",
  			packets_per_slave, USHRT_MAX);
  		packets_per_slave = 1;
  	}
  
  	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_warn("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_warn("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_warn("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_warn("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_warn("Warning: arp_interval module parameter (%d), not in range 0-%d, so it was reset to 0\n",
  			arp_interval, INT_MAX);
  		arp_interval = 0;
  	}
  
  	for (arp_ip_count = 0, i = 0;
  	     (arp_ip_count < BOND_MAX_ARP_TARGETS) && arp_ip_target[i]; i++) {
  		__be32 ip;
  
  		/* not a complete check, but good enough to catch mistakes */
  		if (!in4_pton(arp_ip_target[i], -1, (u8 *)&ip, -1, NULL) ||
  		    !bond_is_ip_target_ok(ip)) {
  			pr_warn("Warning: bad arp_ip_target module parameter (%s), ARP monitoring will not be performed\n",
  				arp_ip_target[i]);
  			arp_interval = 0;
  		} else {
  			if (bond_get_targets_ip(arp_target, ip) == -1)
  				arp_target[arp_ip_count++] = ip;
  			else
  				pr_warn("Warning: duplicate address %pI4 in arp_ip_target, skipping\n",
  					&ip);
  		}
  	}
  
  	if (arp_interval && !arp_ip_count) {
  		/* don't allow arping if no arp_ip_target given... */
  		pr_warn("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 (!arp_interval) {
  			pr_err("arp_validate requires arp_interval\n");
  			return -EINVAL;
  		}
  
  		bond_opt_initstr(&newval, arp_validate);
  		valptr = bond_opt_parse(bond_opt_get(BOND_OPT_ARP_VALIDATE),
  					&newval);
  		if (!valptr) {
  			pr_err("Error: invalid arp_validate \"%s\"\n",
  			       arp_validate);
  			return -EINVAL;
  		}
  		arp_validate_value = valptr->value;
  	} else {
  		arp_validate_value = 0;
  	}
  
  	arp_all_targets_value = 0;
  	if (arp_all_targets) {
  		bond_opt_initstr(&newval, arp_all_targets);
  		valptr = bond_opt_parse(bond_opt_get(BOND_OPT_ARP_ALL_TARGETS),
  					&newval);
  		if (!valptr) {
  			pr_err("Error: invalid arp_all_targets_value \"%s\"\n",
  			       arp_all_targets);
  			arp_all_targets_value = 0;
  		} else {
  			arp_all_targets_value = valptr->value;
  		}
  	}
  
  	if (miimon) {
  		pr_info("MII link monitoring set to %d ms\n", miimon);
  	} else if (arp_interval) {
  		valptr = bond_opt_get_val(BOND_OPT_ARP_VALIDATE,
  					  arp_validate_value);
  		pr_info("ARP monitoring set to %d ms, validate %s, with %d target(s):",
  			arp_interval, valptr->string, arp_ip_count);
  
  		for (i = 0; i < arp_ip_count; i++)
  			pr_cont(" %s", arp_ip_target[i]);
  
  		pr_cont("\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 && !bond_mode_uses_primary(bond_mode)) {
  		/* currently, using a primary only makes sense
  		 * in active backup, TLB or ALB modes
  		 */
  		pr_warn("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) {
  		bond_opt_initstr(&newval, primary_reselect);
  		valptr = bond_opt_parse(bond_opt_get(BOND_OPT_PRIMARY_RESELECT),
  					&newval);
  		if (!valptr) {
  			pr_err("Error: Invalid primary_reselect \"%s\"\n",
  			       primary_reselect);
  			return -EINVAL;
  		}
  		primary_reselect_value = valptr->value;
  	} else {
  		primary_reselect_value = BOND_PRI_RESELECT_ALWAYS;
  	}
  
  	if (fail_over_mac) {
  		bond_opt_initstr(&newval, fail_over_mac);
  		valptr = bond_opt_parse(bond_opt_get(BOND_OPT_FAIL_OVER_MAC),
  					&newval);
  		if (!valptr) {
  			pr_err("Error: invalid fail_over_mac \"%s\"\n",
  			       fail_over_mac);
  			return -EINVAL;
  		}
  		fail_over_mac_value = valptr->value;
  		if (bond_mode != BOND_MODE_ACTIVEBACKUP)
  			pr_warn("Warning: fail_over_mac only affects active-backup mode\n");
  	} else {
  		fail_over_mac_value = BOND_FOM_NONE;
  	}
  
  	bond_opt_initstr(&newval, "default");
  	valptr = bond_opt_parse(
  			bond_opt_get(BOND_OPT_AD_ACTOR_SYS_PRIO),
  				     &newval);
  	if (!valptr) {
  		pr_err("Error: No ad_actor_sys_prio default value");
  		return -EINVAL;
  	}
  	ad_actor_sys_prio = valptr->value;
  
  	valptr = bond_opt_parse(bond_opt_get(BOND_OPT_AD_USER_PORT_KEY),
  				&newval);
  	if (!valptr) {
  		pr_err("Error: No ad_user_port_key default value");
  		return -EINVAL;
  	}
  	ad_user_port_key = valptr->value;
  
  	if (lp_interval == 0) {
  		pr_warn("Warning: ip_interval must be between 1 and %d, so it was reset to %d\n",
  			INT_MAX, BOND_ALB_DEFAULT_LP_INTERVAL);
  		lp_interval = BOND_ALB_DEFAULT_LP_INTERVAL;
  	}
  
  	/* 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->arp_all_targets = arp_all_targets_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;
  	params->lp_interval = lp_interval;
  	params->packets_per_slave = packets_per_slave;
  	params->tlb_dynamic_lb = 1; /* Default value */
  	params->ad_actor_sys_prio = ad_actor_sys_prio;
  	eth_zero_addr(params->ad_actor_system);
  	params->ad_user_port_key = ad_user_port_key;
  	if (packets_per_slave > 0) {
  		params->reciprocal_packets_per_slave =
  			reciprocal_value(packets_per_slave);
  	} else {
  		/* reciprocal_packets_per_slave is unused if
  		 * packets_per_slave is 0 or 1, just initialize it
  		 */
  		params->reciprocal_packets_per_slave =
  			(struct reciprocal_value) { 0 };
  	}
  
  	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);
  
  	netdev_dbg(bond_dev, "Begin bond_init\n");
  
  	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);
  
  	/* Ensure valid dev_addr */
  	if (is_zero_ether_addr(bond_dev->dev_addr) &&
  	    bond_dev->addr_assign_type == NET_ADDR_PERM)
  		eth_hw_addr_random(bond_dev);
  
  	return 0;
  }
  
  unsigned int bond_get_num_tx_queues(void)
  {
  	return 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;
  	struct bonding *bond;
  	struct alb_bond_info *bond_info;
  	int res;
  
  	rtnl_lock();
  
  	bond_dev = alloc_netdev_mq(sizeof(struct bonding),
  				   name ? name : "bond%d", NET_NAME_UNKNOWN,
  				   bond_setup, tx_queues);
  	if (!bond_dev) {
  		pr_err("%s: eek! can't alloc netdev!\n", name);
  		rtnl_unlock();
  		return -ENOMEM;
  	}
  
  	/*
  	 * Initialize rx_hashtbl_used_head to RLB_NULL_INDEX.
  	 * It is set to 0 by default which is wrong.
  	 */
  	bond = netdev_priv(bond_dev);
  	bond_info = &(BOND_ALB_INFO(bond));
  	bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
  
  	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);
  	struct bonding *bond, *tmp_bond;
  	LIST_HEAD(list);
  
  	bond_destroy_sysfs(bn);
  
  	/* Kill off any bonds created after unregistering bond rtnl ops */
  	rtnl_lock();
  	list_for_each_entry_safe(bond, tmp_bond, &bn->dev_list, bond_list)
  		unregister_netdevice_queue(bond->dev, &list);
  	unregister_netdevice_many(&list);
  	rtnl_unlock();
  
  	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 = bond_netlink_init();
  	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:
  	bond_destroy_debugfs();
  	bond_netlink_fini();
  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();
  
  	bond_netlink_fini();
  	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");
  