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bond_alb.c

/*
 * Copyright(c) 1999 - 2004 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 */

//#define BONDING_DEBUG 1

#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/pkt_sched.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_bonding.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <net/ipx.h>
#include <net/arp.h>
#include <asm/byteorder.h>
#include "bonding.h"
#include "bond_alb.h"


#define ALB_TIMER_TICKS_PER_SEC         10      /* should be a divisor of HZ */
#define BOND_TLB_REBALANCE_INTERVAL 10    /* In seconds, periodic re-balancing.
                               * Used for division - never set
                               * to zero !!!
                               */
#define BOND_ALB_LP_INTERVAL      1 /* In seconds, periodic send of
                               * learning packets to the switch
                               */

#define BOND_TLB_REBALANCE_TICKS (BOND_TLB_REBALANCE_INTERVAL \
                          * ALB_TIMER_TICKS_PER_SEC)

#define BOND_ALB_LP_TICKS (BOND_ALB_LP_INTERVAL \
                     * ALB_TIMER_TICKS_PER_SEC)

#define TLB_HASH_TABLE_SIZE 256     /* The size of the clients hash table.
                         * Note that this value MUST NOT be smaller
                         * because the key hash table is BYTE wide !
                         */


#define TLB_NULL_INDEX        0xffffffff
#define MAX_LP_BURST          3

/* rlb defs */
#define RLB_HASH_TABLE_SIZE   256
#define RLB_NULL_INDEX        0xffffffff
#define RLB_UPDATE_DELAY      2*ALB_TIMER_TICKS_PER_SEC /* 2 seconds */
#define RLB_ARP_BURST_SIZE    2
#define RLB_UPDATE_RETRY      3     /* 3-ticks - must be smaller than the rlb
                               * rebalance interval (5 min).
                               */
/* RLB_PROMISC_TIMEOUT = 10 sec equals the time that the current slave is
 * promiscuous after failover
 */
#define RLB_PROMISC_TIMEOUT   10*ALB_TIMER_TICKS_PER_SEC

static const u8 mac_bcast[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};
static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;

#pragma pack(1)
struct learning_pkt {
      u8 mac_dst[ETH_ALEN];
      u8 mac_src[ETH_ALEN];
      __be16 type;
      u8 padding[ETH_ZLEN - ETH_HLEN];
};

struct arp_pkt {
      __be16  hw_addr_space;
      __be16  prot_addr_space;
      u8      hw_addr_len;
      u8      prot_addr_len;
      __be16  op_code;
      u8      mac_src[ETH_ALEN];    /* sender hardware address */
      __be32  ip_src;               /* sender IP address */
      u8      mac_dst[ETH_ALEN];    /* target hardware address */
      __be32  ip_dst;               /* target IP address */
};
#pragma pack()

static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
{
      return (struct arp_pkt *)skb_network_header(skb);
}

/* Forward declaration */
static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[]);

static inline u8 _simple_hash(const u8 *hash_start, int hash_size)
{
      int i;
      u8 hash = 0;

      for (i = 0; i < hash_size; i++) {
            hash ^= hash_start[i];
      }

      return hash;
}

/*********************** tlb specific functions ***************************/

static inline void _lock_tx_hashtbl(struct bonding *bond)
{
      spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

static inline void _unlock_tx_hashtbl(struct bonding *bond)
{
      spin_unlock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

/* Caller must hold tx_hashtbl lock */
static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
{
      if (save_load) {
            entry->load_history = 1 + entry->tx_bytes /
                              BOND_TLB_REBALANCE_INTERVAL;
            entry->tx_bytes = 0;
      }

      entry->tx_slave = NULL;
      entry->next = TLB_NULL_INDEX;
      entry->prev = TLB_NULL_INDEX;
}

static inline void tlb_init_slave(struct slave *slave)
{
      SLAVE_TLB_INFO(slave).load = 0;
      SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
}

/* Caller must hold bond lock for read */
static void tlb_clear_slave(struct bonding *bond, struct slave *slave, int save_load)
{
      struct tlb_client_info *tx_hash_table;
      u32 index;

      _lock_tx_hashtbl(bond);

      /* clear slave from tx_hashtbl */
      tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;

      index = SLAVE_TLB_INFO(slave).head;
      while (index != TLB_NULL_INDEX) {
            u32 next_index = tx_hash_table[index].next;
            tlb_init_table_entry(&tx_hash_table[index], save_load);
            index = next_index;
      }

      tlb_init_slave(slave);

      _unlock_tx_hashtbl(bond);
}

/* Must be called before starting the monitor timer */
static int tlb_initialize(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
      struct tlb_client_info *new_hashtbl;
      int i;

      spin_lock_init(&(bond_info->tx_hashtbl_lock));

      new_hashtbl = kzalloc(size, GFP_KERNEL);
      if (!new_hashtbl) {
            printk(KERN_ERR DRV_NAME
                   ": %s: Error: Failed to allocate TLB hash table\n",
                   bond->dev->name);
            return -1;
      }
      _lock_tx_hashtbl(bond);

      bond_info->tx_hashtbl = new_hashtbl;

      for (i = 0; i < TLB_HASH_TABLE_SIZE; i++) {
            tlb_init_table_entry(&bond_info->tx_hashtbl[i], 1);
      }

      _unlock_tx_hashtbl(bond);

      return 0;
}

/* Must be called only after all slaves have been released */
static void tlb_deinitialize(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

      _lock_tx_hashtbl(bond);

      kfree(bond_info->tx_hashtbl);
      bond_info->tx_hashtbl = NULL;

      _unlock_tx_hashtbl(bond);
}

/* Caller must hold bond lock for read */
static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
{
      struct slave *slave, *least_loaded;
      s64 max_gap;
      int i, found = 0;

      /* Find the first enabled slave */
      bond_for_each_slave(bond, slave, i) {
            if (SLAVE_IS_OK(slave)) {
                  found = 1;
                  break;
            }
      }

      if (!found) {
            return NULL;
      }

      least_loaded = slave;
      max_gap = (s64)(slave->speed << 20) - /* Convert to Megabit per sec */
                  (s64)(SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */

      /* Find the slave with the largest gap */
      bond_for_each_slave_from(bond, slave, i, least_loaded) {
            if (SLAVE_IS_OK(slave)) {
                  s64 gap = (s64)(slave->speed << 20) -
                              (s64)(SLAVE_TLB_INFO(slave).load << 3);
                  if (max_gap < gap) {
                        least_loaded = slave;
                        max_gap = gap;
                  }
            }
      }

      return least_loaded;
}

/* Caller must hold bond lock for read */
static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index, u32 skb_len)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct tlb_client_info *hash_table;
      struct slave *assigned_slave;

      _lock_tx_hashtbl(bond);

      hash_table = bond_info->tx_hashtbl;
      assigned_slave = hash_table[hash_index].tx_slave;
      if (!assigned_slave) {
            assigned_slave = tlb_get_least_loaded_slave(bond);

            if (assigned_slave) {
                  struct tlb_slave_info *slave_info =
                        &(SLAVE_TLB_INFO(assigned_slave));
                  u32 next_index = slave_info->head;

                  hash_table[hash_index].tx_slave = assigned_slave;
                  hash_table[hash_index].next = next_index;
                  hash_table[hash_index].prev = TLB_NULL_INDEX;

                  if (next_index != TLB_NULL_INDEX) {
                        hash_table[next_index].prev = hash_index;
                  }

                  slave_info->head = hash_index;
                  slave_info->load +=
                        hash_table[hash_index].load_history;
            }
      }

      if (assigned_slave) {
            hash_table[hash_index].tx_bytes += skb_len;
      }

      _unlock_tx_hashtbl(bond);

      return assigned_slave;
}

/*********************** rlb specific functions ***************************/
static inline void _lock_rx_hashtbl(struct bonding *bond)
{
      spin_lock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
}

static inline void _unlock_rx_hashtbl(struct bonding *bond)
{
      spin_unlock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
}

/* when an ARP REPLY is received from a client update its info
 * in the rx_hashtbl
 */
static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct rlb_client_info *client_info;
      u32 hash_index;

      _lock_rx_hashtbl(bond);

      hash_index = _simple_hash((u8*)&(arp->ip_src), sizeof(arp->ip_src));
      client_info = &(bond_info->rx_hashtbl[hash_index]);

      if ((client_info->assigned) &&
          (client_info->ip_src == arp->ip_dst) &&
          (client_info->ip_dst == arp->ip_src)) {
            /* update the clients MAC address */
            memcpy(client_info->mac_dst, arp->mac_src, ETH_ALEN);
            client_info->ntt = 1;
            bond_info->rx_ntt = 1;
      }

      _unlock_rx_hashtbl(bond);
}

static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct packet_type *ptype, struct net_device *orig_dev)
{
      struct bonding *bond = bond_dev->priv;
      struct arp_pkt *arp = (struct arp_pkt *)skb->data;
      int res = NET_RX_DROP;

      if (bond_dev->nd_net != &init_net)
            goto out;

      if (!(bond_dev->flags & IFF_MASTER))
            goto out;

      if (!arp) {
            dprintk("Packet has no ARP data\n");
            goto out;
      }

      if (skb->len < sizeof(struct arp_pkt)) {
            dprintk("Packet is too small to be an ARP\n");
            goto out;
      }

      if (arp->op_code == htons(ARPOP_REPLY)) {
            /* update rx hash table for this ARP */
            rlb_update_entry_from_arp(bond, arp);
            dprintk("Server received an ARP Reply from client\n");
      }

      res = NET_RX_SUCCESS;

out:
      dev_kfree_skb(skb);

      return res;
}

/* Caller must hold bond lock for read */
static struct slave *rlb_next_rx_slave(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct slave *rx_slave, *slave, *start_at;
      int i = 0;

      if (bond_info->next_rx_slave) {
            start_at = bond_info->next_rx_slave;
      } else {
            start_at = bond->first_slave;
      }

      rx_slave = NULL;

      bond_for_each_slave_from(bond, slave, i, start_at) {
            if (SLAVE_IS_OK(slave)) {
                  if (!rx_slave) {
                        rx_slave = slave;
                  } else if (slave->speed > rx_slave->speed) {
                        rx_slave = slave;
                  }
            }
      }

      if (rx_slave) {
            bond_info->next_rx_slave = rx_slave->next;
      }

      return rx_slave;
}

/* teach the switch the mac of a disabled slave
 * on the primary for fault tolerance
 *
 * Caller must hold bond->curr_slave_lock for write or bond lock for write
 */
static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
{
      if (!bond->curr_active_slave) {
            return;
      }

      if (!bond->alb_info.primary_is_promisc) {
            bond->alb_info.primary_is_promisc = 1;
            dev_set_promiscuity(bond->curr_active_slave->dev, 1);
      }

      bond->alb_info.rlb_promisc_timeout_counter = 0;

      alb_send_learning_packets(bond->curr_active_slave, addr);
}

/* slave being removed should not be active at this point
 *
 * Caller must hold bond lock for read
 */
static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct rlb_client_info *rx_hash_table;
      u32 index, next_index;

      /* clear slave from rx_hashtbl */
      _lock_rx_hashtbl(bond);

      rx_hash_table = bond_info->rx_hashtbl;
      index = bond_info->rx_hashtbl_head;
      for (; index != RLB_NULL_INDEX; index = next_index) {
            next_index = rx_hash_table[index].next;
            if (rx_hash_table[index].slave == slave) {
                  struct slave *assigned_slave = rlb_next_rx_slave(bond);

                  if (assigned_slave) {
                        rx_hash_table[index].slave = assigned_slave;
                        if (memcmp(rx_hash_table[index].mac_dst,
                                 mac_bcast, ETH_ALEN)) {
                              bond_info->rx_hashtbl[index].ntt = 1;
                              bond_info->rx_ntt = 1;
                              /* A slave has been removed from the
                               * table because it is either disabled
                               * or being released. We must retry the
                               * update to avoid clients from not
                               * being updated & disconnecting when
                               * there is stress
                               */
                              bond_info->rlb_update_retry_counter =
                                    RLB_UPDATE_RETRY;
                        }
                  } else {  /* there is no active slave */
                        rx_hash_table[index].slave = NULL;
                  }
            }
      }

      _unlock_rx_hashtbl(bond);

      write_lock_bh(&bond->curr_slave_lock);

      if (slave != bond->curr_active_slave) {
            rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
      }

      write_unlock_bh(&bond->curr_slave_lock);
}

static void rlb_update_client(struct rlb_client_info *client_info)
{
      int i;

      if (!client_info->slave) {
            return;
      }

      for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
            struct sk_buff *skb;

            skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
                         client_info->ip_dst,
                         client_info->slave->dev,
                         client_info->ip_src,
                         client_info->mac_dst,
                         client_info->slave->dev->dev_addr,
                         client_info->mac_dst);
            if (!skb) {
                  printk(KERN_ERR DRV_NAME
                         ": %s: Error: failed to create an ARP packet\n",
                         client_info->slave->dev->master->name);
                  continue;
            }

            skb->dev = client_info->slave->dev;

            if (client_info->tag) {
                  skb = vlan_put_tag(skb, client_info->vlan_id);
                  if (!skb) {
                        printk(KERN_ERR DRV_NAME
                               ": %s: Error: failed to insert VLAN tag\n",
                               client_info->slave->dev->master->name);
                        continue;
                  }
            }

            arp_xmit(skb);
      }
}

/* sends ARP REPLIES that update the clients that need updating */
static void rlb_update_rx_clients(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct rlb_client_info *client_info;
      u32 hash_index;

      _lock_rx_hashtbl(bond);

      hash_index = bond_info->rx_hashtbl_head;
      for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
            client_info = &(bond_info->rx_hashtbl[hash_index]);
            if (client_info->ntt) {
                  rlb_update_client(client_info);
                  if (bond_info->rlb_update_retry_counter == 0) {
                        client_info->ntt = 0;
                  }
            }
      }

      /* do not update the entries again untill this counter is zero so that
       * not to confuse the clients.
       */
      bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;

      _unlock_rx_hashtbl(bond);
}

/* The slave was assigned a new mac address - update the clients */
static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct rlb_client_info *client_info;
      int ntt = 0;
      u32 hash_index;

      _lock_rx_hashtbl(bond);

      hash_index = bond_info->rx_hashtbl_head;
      for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
            client_info = &(bond_info->rx_hashtbl[hash_index]);

            if ((client_info->slave == slave) &&
                memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
                  client_info->ntt = 1;
                  ntt = 1;
            }
      }

      // update the team's flag only after the whole iteration
      if (ntt) {
            bond_info->rx_ntt = 1;
            //fasten the change
            bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
      }

      _unlock_rx_hashtbl(bond);
}

/* mark all clients using src_ip to be updated */
static void rlb_req_update_subnet_clients(struct bonding *bond, __be32 src_ip)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct rlb_client_info *client_info;
      u32 hash_index;

      _lock_rx_hashtbl(bond);

      hash_index = bond_info->rx_hashtbl_head;
      for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
            client_info = &(bond_info->rx_hashtbl[hash_index]);

            if (!client_info->slave) {
                  printk(KERN_ERR DRV_NAME
                         ": %s: Error: found a client with no channel in "
                         "the client's hash table\n",
                         bond->dev->name);
                  continue;
            }
            /*update all clients using this src_ip, that are not assigned
             * to the team's address (curr_active_slave) and have a known
             * unicast mac address.
             */
            if ((client_info->ip_src == src_ip) &&
                memcmp(client_info->slave->dev->dev_addr,
                     bond->dev->dev_addr, ETH_ALEN) &&
                memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
                  client_info->ntt = 1;
                  bond_info->rx_ntt = 1;
            }
      }

      _unlock_rx_hashtbl(bond);
}

/* Caller must hold both bond and ptr locks for read */
static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct arp_pkt *arp = arp_pkt(skb);
      struct slave *assigned_slave;
      struct rlb_client_info *client_info;
      u32 hash_index = 0;

      _lock_rx_hashtbl(bond);

      hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_src));
      client_info = &(bond_info->rx_hashtbl[hash_index]);

      if (client_info->assigned) {
            if ((client_info->ip_src == arp->ip_src) &&
                (client_info->ip_dst == arp->ip_dst)) {
                  /* the entry is already assigned to this client */
                  if (memcmp(arp->mac_dst, mac_bcast, ETH_ALEN)) {
                        /* update mac address from arp */
                        memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
                  }

                  assigned_slave = client_info->slave;
                  if (assigned_slave) {
                        _unlock_rx_hashtbl(bond);
                        return assigned_slave;
                  }
            } else {
                  /* the entry is already assigned to some other client,
                   * move the old client to primary (curr_active_slave) so
                   * that the new client can be assigned to this entry.
                   */
                  if (bond->curr_active_slave &&
                      client_info->slave != bond->curr_active_slave) {
                        client_info->slave = bond->curr_active_slave;
                        rlb_update_client(client_info);
                  }
            }
      }
      /* assign a new slave */
      assigned_slave = rlb_next_rx_slave(bond);

      if (assigned_slave) {
            client_info->ip_src = arp->ip_src;
            client_info->ip_dst = arp->ip_dst;
            /* arp->mac_dst is broadcast for arp reqeusts.
             * will be updated with clients actual unicast mac address
             * upon receiving an arp reply.
             */
            memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
            client_info->slave = assigned_slave;

            if (memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
                  client_info->ntt = 1;
                  bond->alb_info.rx_ntt = 1;
            } else {
                  client_info->ntt = 0;
            }

            if (!list_empty(&bond->vlan_list)) {
                  unsigned short vlan_id;
                  int res = vlan_get_tag(skb, &vlan_id);
                  if (!res) {
                        client_info->tag = 1;
                        client_info->vlan_id = vlan_id;
                  }
            }

            if (!client_info->assigned) {
                  u32 prev_tbl_head = bond_info->rx_hashtbl_head;
                  bond_info->rx_hashtbl_head = hash_index;
                  client_info->next = prev_tbl_head;
                  if (prev_tbl_head != RLB_NULL_INDEX) {
                        bond_info->rx_hashtbl[prev_tbl_head].prev =
                              hash_index;
                  }
                  client_info->assigned = 1;
            }
      }

      _unlock_rx_hashtbl(bond);

      return assigned_slave;
}

/* chooses (and returns) transmit channel for arp reply
 * does not choose channel for other arp types since they are
 * sent on the curr_active_slave
 */
static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
{
      struct arp_pkt *arp = arp_pkt(skb);
      struct slave *tx_slave = NULL;

      if (arp->op_code == __constant_htons(ARPOP_REPLY)) {
            /* the arp must be sent on the selected
            * rx channel
            */
            tx_slave = rlb_choose_channel(skb, bond);
            if (tx_slave) {
                  memcpy(arp->mac_src,tx_slave->dev->dev_addr, ETH_ALEN);
            }
            dprintk("Server sent ARP Reply packet\n");
      } else if (arp->op_code == __constant_htons(ARPOP_REQUEST)) {
            /* Create an entry in the rx_hashtbl for this client as a
             * place holder.
             * When the arp reply is received the entry will be updated
             * with the correct unicast address of the client.
             */
            rlb_choose_channel(skb, bond);

            /* The ARP relpy packets must be delayed so that
             * they can cancel out the influence of the ARP request.
             */
            bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;

            /* arp requests are broadcast and are sent on the primary
             * the arp request will collapse all clients on the subnet to
             * the primary slave. We must register these clients to be
             * updated with their assigned mac.
             */
            rlb_req_update_subnet_clients(bond, arp->ip_src);
            dprintk("Server sent ARP Request packet\n");
      }

      return tx_slave;
}

/* Caller must hold bond lock for read */
static void rlb_rebalance(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct slave *assigned_slave;
      struct rlb_client_info *client_info;
      int ntt;
      u32 hash_index;

      _lock_rx_hashtbl(bond);

      ntt = 0;
      hash_index = bond_info->rx_hashtbl_head;
      for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
            client_info = &(bond_info->rx_hashtbl[hash_index]);
            assigned_slave = rlb_next_rx_slave(bond);
            if (assigned_slave && (client_info->slave != assigned_slave)) {
                  client_info->slave = assigned_slave;
                  client_info->ntt = 1;
                  ntt = 1;
            }
      }

      /* update the team's flag only after the whole iteration */
      if (ntt) {
            bond_info->rx_ntt = 1;
      }
      _unlock_rx_hashtbl(bond);
}

/* Caller must hold rx_hashtbl lock */
static void rlb_init_table_entry(struct rlb_client_info *entry)
{
      memset(entry, 0, sizeof(struct rlb_client_info));
      entry->next = RLB_NULL_INDEX;
      entry->prev = RLB_NULL_INDEX;
}

static int rlb_initialize(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct packet_type *pk_type = &(BOND_ALB_INFO(bond).rlb_pkt_type);
      struct rlb_client_info  *new_hashtbl;
      int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
      int i;

      spin_lock_init(&(bond_info->rx_hashtbl_lock));

      new_hashtbl = kmalloc(size, GFP_KERNEL);
      if (!new_hashtbl) {
            printk(KERN_ERR DRV_NAME
                   ": %s: Error: Failed to allocate RLB hash table\n",
                   bond->dev->name);
            return -1;
      }
      _lock_rx_hashtbl(bond);

      bond_info->rx_hashtbl = new_hashtbl;

      bond_info->rx_hashtbl_head = RLB_NULL_INDEX;

      for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
            rlb_init_table_entry(bond_info->rx_hashtbl + i);
      }

      _unlock_rx_hashtbl(bond);

      /*initialize packet type*/
      pk_type->type = __constant_htons(ETH_P_ARP);
      pk_type->dev = bond->dev;
      pk_type->func = rlb_arp_recv;

      /* register to receive ARPs */
      dev_add_pack(pk_type);

      return 0;
}

static void rlb_deinitialize(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

      dev_remove_pack(&(bond_info->rlb_pkt_type));

      _lock_rx_hashtbl(bond);

      kfree(bond_info->rx_hashtbl);
      bond_info->rx_hashtbl = NULL;
      bond_info->rx_hashtbl_head = RLB_NULL_INDEX;

      _unlock_rx_hashtbl(bond);
}

static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      u32 curr_index;

      _lock_rx_hashtbl(bond);

      curr_index = bond_info->rx_hashtbl_head;
      while (curr_index != RLB_NULL_INDEX) {
            struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
            u32 next_index = bond_info->rx_hashtbl[curr_index].next;
            u32 prev_index = bond_info->rx_hashtbl[curr_index].prev;

            if (curr->tag && (curr->vlan_id == vlan_id)) {
                  if (curr_index == bond_info->rx_hashtbl_head) {
                        bond_info->rx_hashtbl_head = next_index;
                  }
                  if (prev_index != RLB_NULL_INDEX) {
                        bond_info->rx_hashtbl[prev_index].next = next_index;
                  }
                  if (next_index != RLB_NULL_INDEX) {
                        bond_info->rx_hashtbl[next_index].prev = prev_index;
                  }

                  rlb_init_table_entry(curr);
            }

            curr_index = next_index;
      }

      _unlock_rx_hashtbl(bond);
}

/*********************** tlb/rlb shared functions *********************/

static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
{
      struct bonding *bond = bond_get_bond_by_slave(slave);
      struct learning_pkt pkt;
      int size = sizeof(struct learning_pkt);
      int i;

      memset(&pkt, 0, size);
      memcpy(pkt.mac_dst, mac_addr, ETH_ALEN);
      memcpy(pkt.mac_src, mac_addr, ETH_ALEN);
      pkt.type = __constant_htons(ETH_P_LOOP);

      for (i = 0; i < MAX_LP_BURST; i++) {
            struct sk_buff *skb;
            char *data;

            skb = dev_alloc_skb(size);
            if (!skb) {
                  return;
            }

            data = skb_put(skb, size);
            memcpy(data, &pkt, size);

            skb_reset_mac_header(skb);
            skb->network_header = skb->mac_header + ETH_HLEN;
            skb->protocol = pkt.type;
            skb->priority = TC_PRIO_CONTROL;
            skb->dev = slave->dev;

            if (!list_empty(&bond->vlan_list)) {
                  struct vlan_entry *vlan;

                  vlan = bond_next_vlan(bond,
                                    bond->alb_info.current_alb_vlan);

                  bond->alb_info.current_alb_vlan = vlan;
                  if (!vlan) {
                        kfree_skb(skb);
                        continue;
                  }

                  skb = vlan_put_tag(skb, vlan->vlan_id);
                  if (!skb) {
                        printk(KERN_ERR DRV_NAME
                               ": %s: Error: failed to insert VLAN tag\n",
                               bond->dev->name);
                        continue;
                  }
            }

            dev_queue_xmit(skb);
      }
}

/* hw is a boolean parameter that determines whether we should try and
 * set the hw address of the device as well as the hw address of the
 * net_device
 */
static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw)
{
      struct net_device *dev = slave->dev;
      struct sockaddr s_addr;

      if (!hw) {
            memcpy(dev->dev_addr, addr, dev->addr_len);
            return 0;
      }

      /* for rlb each slave must have a unique hw mac addresses so that */
      /* each slave will receive packets destined to a different mac */
      memcpy(s_addr.sa_data, addr, dev->addr_len);
      s_addr.sa_family = dev->type;
      if (dev_set_mac_address(dev, &s_addr)) {
            printk(KERN_ERR DRV_NAME
                   ": %s: Error: dev_set_mac_address of dev %s failed! ALB "
                   "mode requires that the base driver support setting "
                   "the hw address also when the network device's "
                   "interface is open\n",
                   dev->master->name, dev->name);
            return -EOPNOTSUPP;
      }
      return 0;
}

/*
 * Swap MAC addresses between two slaves.
 *
 * Called with RTNL held, and no other locks.
 *
 */

static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
{
      u8 tmp_mac_addr[ETH_ALEN];

      memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
      alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled);
      alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled);

}

/*
 * Send learning packets after MAC address swap.
 *
 * Called with RTNL and no other locks
 */
static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
                        struct slave *slave2)
{
      int slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
      struct slave *disabled_slave = NULL;

      ASSERT_RTNL();

      /* fasten the change in the switch */
      if (SLAVE_IS_OK(slave1)) {
            alb_send_learning_packets(slave1, slave1->dev->dev_addr);
            if (bond->alb_info.rlb_enabled) {
                  /* inform the clients that the mac address
                   * has changed
                   */
                  rlb_req_update_slave_clients(bond, slave1);
            }
      } else {
            disabled_slave = slave1;
      }

      if (SLAVE_IS_OK(slave2)) {
            alb_send_learning_packets(slave2, slave2->dev->dev_addr);
            if (bond->alb_info.rlb_enabled) {
                  /* inform the clients that the mac address
                   * has changed
                   */
                  rlb_req_update_slave_clients(bond, slave2);
            }
      } else {
            disabled_slave = slave2;
      }

      if (bond->alb_info.rlb_enabled && slaves_state_differ) {
            /* A disabled slave was assigned an active mac addr */
            rlb_teach_disabled_mac_on_primary(bond,
                                      disabled_slave->dev->dev_addr);
      }
}

/**
 * alb_change_hw_addr_on_detach
 * @bond: bonding we're working on
 * @slave: the slave that was just detached
 *
 * We assume that @slave was already detached from the slave list.
 *
 * If @slave's permanent hw address is different both from its current
 * address and from @bond's address, then somewhere in the bond there's
 * a slave that has @slave's permanet address as its current address.
 * We'll make sure that that slave no longer uses @slave's permanent address.
 *
 * Caller must hold RTNL and no other locks
 */
static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
{
      int perm_curr_diff;
      int perm_bond_diff;

      perm_curr_diff = memcmp(slave->perm_hwaddr,
                        slave->dev->dev_addr,
                        ETH_ALEN);
      perm_bond_diff = memcmp(slave->perm_hwaddr,
                        bond->dev->dev_addr,
                        ETH_ALEN);

      if (perm_curr_diff && perm_bond_diff) {
            struct slave *tmp_slave;
            int i, found = 0;

            bond_for_each_slave(bond, tmp_slave, i) {
                  if (!memcmp(slave->perm_hwaddr,
                            tmp_slave->dev->dev_addr,
                            ETH_ALEN)) {
                        found = 1;
                        break;
                  }
            }

            if (found) {
                  /* locking: needs RTNL and nothing else */
                  alb_swap_mac_addr(bond, slave, tmp_slave);
                  alb_fasten_mac_swap(bond, slave, tmp_slave);
            }
      }
}

/**
 * alb_handle_addr_collision_on_attach
 * @bond: bonding we're working on
 * @slave: the slave that was just attached
 *
 * checks uniqueness of slave's mac address and handles the case the
 * new slave uses the bonds mac address.
 *
 * If the permanent hw address of @slave is @bond's hw address, we need to
 * find a different hw address to give @slave, that isn't in use by any other
 * slave in the bond. This address must be, of course, one of the premanent
 * addresses of the other slaves.
 *
 * We go over the slave list, and for each slave there we compare its
 * permanent hw address with the current address of all the other slaves.
 * If no match was found, then we've found a slave with a permanent address
 * that isn't used by any other slave in the bond, so we can assign it to
 * @slave.
 *
 * assumption: this function is called before @slave is attached to the
 *           bond slave list.
 *
 * caller must hold the bond lock for write since the mac addresses are compared
 * and may be swapped.
 */
static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
{
      struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave;
      struct slave *has_bond_addr = bond->curr_active_slave;
      int i, j, found = 0;

      if (bond->slave_cnt == 0) {
            /* this is the first slave */
            return 0;
      }

      /* if slave's mac address differs from bond's mac address
       * check uniqueness of slave's mac address against the other
       * slaves in the bond.
       */
      if (memcmp(slave->perm_hwaddr, bond->dev->dev_addr, ETH_ALEN)) {
            bond_for_each_slave(bond, tmp_slave1, i) {
                  if (!memcmp(tmp_slave1->dev->dev_addr, slave->dev->dev_addr,
                            ETH_ALEN)) {
                        found = 1;
                        break;
                  }
            }

            if (!found)
                  return 0;

            /* Try setting slave mac to bond address and fall-through
               to code handling that situation below... */
            alb_set_slave_mac_addr(slave, bond->dev->dev_addr,
                               bond->alb_info.rlb_enabled);
      }

      /* The slave's address is equal to the address of the bond.
       * Search for a spare address in the bond for this slave.
       */
      free_mac_slave = NULL;

      bond_for_each_slave(bond, tmp_slave1, i) {
            found = 0;
            bond_for_each_slave(bond, tmp_slave2, j) {
                  if (!memcmp(tmp_slave1->perm_hwaddr,
                            tmp_slave2->dev->dev_addr,
                            ETH_ALEN)) {
                        found = 1;
                        break;
                  }
            }

            if (!found) {
                  /* no slave has tmp_slave1's perm addr
                   * as its curr addr
                   */
                  free_mac_slave = tmp_slave1;
                  break;
            }

            if (!has_bond_addr) {
                  if (!memcmp(tmp_slave1->dev->dev_addr,
                            bond->dev->dev_addr,
                            ETH_ALEN)) {

                        has_bond_addr = tmp_slave1;
                  }
            }
      }

      if (free_mac_slave) {
            alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr,
                               bond->alb_info.rlb_enabled);

            printk(KERN_WARNING DRV_NAME
                   ": %s: Warning: the hw address of slave %s is in use by "
                   "the bond; giving it the hw address of %s\n",
                   bond->dev->name, slave->dev->name, free_mac_slave->dev->name);

      } else if (has_bond_addr) {
            printk(KERN_ERR DRV_NAME
                   ": %s: Error: the hw address of slave %s is in use by the "
                   "bond; couldn't find a slave with a free hw address to "
                   "give it (this should not have happened)\n",
                   bond->dev->name, slave->dev->name);
            return -EFAULT;
      }

      return 0;
}

/**
 * alb_set_mac_address
 * @bond:
 * @addr:
 *
 * In TLB mode all slaves are configured to the bond's hw address, but set
 * their dev_addr field to different addresses (based on their permanent hw
 * addresses).
 *
 * For each slave, this function sets the interface to the new address and then
 * changes its dev_addr field to its previous value.
 *
 * Unwinding assumes bond's mac address has not yet changed.
 */
static int alb_set_mac_address(struct bonding *bond, void *addr)
{
      struct sockaddr sa;
      struct slave *slave, *stop_at;
      char tmp_addr[ETH_ALEN];
      int res;
      int i;

      if (bond->alb_info.rlb_enabled) {
            return 0;
      }

      bond_for_each_slave(bond, slave, i) {
            if (slave->dev->set_mac_address == NULL) {
                  res = -EOPNOTSUPP;
                  goto unwind;
            }

            /* save net_device's current hw address */
            memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);

            res = dev_set_mac_address(slave->dev, addr);

            /* restore net_device's hw address */
            memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);

            if (res) {
                  goto unwind;
            }
      }

      return 0;

unwind:
      memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
      sa.sa_family = bond->dev->type;

      /* unwind from head to the slave that failed */
      stop_at = slave;
      bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
            memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
            dev_set_mac_address(slave->dev, &sa);
            memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
      }

      return res;
}

/************************ exported alb funcions ************************/

int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
{
      int res;

      res = tlb_initialize(bond);
      if (res) {
            return res;
      }

      if (rlb_enabled) {
            bond->alb_info.rlb_enabled = 1;
            /* initialize rlb */
            res = rlb_initialize(bond);
            if (res) {
                  tlb_deinitialize(bond);
                  return res;
            }
      } else {
            bond->alb_info.rlb_enabled = 0;
      }

      return 0;
}

void bond_alb_deinitialize(struct bonding *bond)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

      tlb_deinitialize(bond);

      if (bond_info->rlb_enabled) {
            rlb_deinitialize(bond);
      }
}

int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
{
      struct bonding *bond = bond_dev->priv;
      struct ethhdr *eth_data;
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct slave *tx_slave = NULL;
      static const __be32 ip_bcast = htonl(0xffffffff);
      int hash_size = 0;
      int do_tx_balance = 1;
      u32 hash_index = 0;
      const u8 *hash_start = NULL;
      int res = 1;

      skb_reset_mac_header(skb);
      eth_data = eth_hdr(skb);

      /* make sure that the curr_active_slave and the slaves list do
       * not change during tx
       */
      read_lock(&bond->lock);
      read_lock(&bond->curr_slave_lock);

      if (!BOND_IS_OK(bond)) {
            goto out;
      }

      switch (ntohs(skb->protocol)) {
      case ETH_P_IP: {
            const struct iphdr *iph = ip_hdr(skb);

            if ((memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) ||
                (iph->daddr == ip_bcast) ||
                (iph->protocol == IPPROTO_IGMP)) {
                  do_tx_balance = 0;
                  break;
            }
            hash_start = (char *)&(iph->daddr);
            hash_size = sizeof(iph->daddr);
      }
            break;
      case ETH_P_IPV6:
            if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
                  do_tx_balance = 0;
                  break;
            }

            hash_start = (char *)&(ipv6_hdr(skb)->daddr);
            hash_size = sizeof(ipv6_hdr(skb)->daddr);
            break;
      case ETH_P_IPX:
            if (ipx_hdr(skb)->ipx_checksum != IPX_NO_CHECKSUM) {
                  /* something is wrong with this packet */
                  do_tx_balance = 0;
                  break;
            }

            if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
                  /* The only protocol worth balancing in
                   * this family since it has an "ARP" like
                   * mechanism
                   */
                  do_tx_balance = 0;
                  break;
            }

            hash_start = (char*)eth_data->h_dest;
            hash_size = ETH_ALEN;
            break;
      case ETH_P_ARP:
            do_tx_balance = 0;
            if (bond_info->rlb_enabled) {
                  tx_slave = rlb_arp_xmit(skb, bond);
            }
            break;
      default:
            do_tx_balance = 0;
            break;
      }

      if (do_tx_balance) {
            hash_index = _simple_hash(hash_start, hash_size);
            tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
      }

      if (!tx_slave) {
            /* unbalanced or unassigned, send through primary */
            tx_slave = bond->curr_active_slave;
            bond_info->unbalanced_load += skb->len;
      }

      if (tx_slave && SLAVE_IS_OK(tx_slave)) {
            if (tx_slave != bond->curr_active_slave) {
                  memcpy(eth_data->h_source,
                         tx_slave->dev->dev_addr,
                         ETH_ALEN);
            }

            res = bond_dev_queue_xmit(bond, skb, tx_slave->dev);
      } else {
            if (tx_slave) {
                  tlb_clear_slave(bond, tx_slave, 0);
            }
      }

out:
      if (res) {
            /* no suitable interface, frame not sent */
            dev_kfree_skb(skb);
      }
      read_unlock(&bond->curr_slave_lock);
      read_unlock(&bond->lock);
      return 0;
}

void bond_alb_monitor(struct work_struct *work)
{
      struct bonding *bond = container_of(work, struct bonding,
                                  alb_work.work);
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
      struct slave *slave;
      int i;

      read_lock(&bond->lock);

      if (bond->kill_timers) {
            goto out;
      }

      if (bond->slave_cnt == 0) {
            bond_info->tx_rebalance_counter = 0;
            bond_info->lp_counter = 0;
            goto re_arm;
      }

      bond_info->tx_rebalance_counter++;
      bond_info->lp_counter++;

      /* send learning packets */
      if (bond_info->lp_counter >= BOND_ALB_LP_TICKS) {
            /* change of curr_active_slave involves swapping of mac addresses.
             * in order to avoid this swapping from happening while
             * sending the learning packets, the curr_slave_lock must be held for
             * read.
             */
            read_lock(&bond->curr_slave_lock);

            bond_for_each_slave(bond, slave, i) {
                  alb_send_learning_packets(slave, slave->dev->dev_addr);
            }

            read_unlock(&bond->curr_slave_lock);

            bond_info->lp_counter = 0;
      }

      /* rebalance tx traffic */
      if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {

            read_lock(&bond->curr_slave_lock);

            bond_for_each_slave(bond, slave, i) {
                  tlb_clear_slave(bond, slave, 1);
                  if (slave == bond->curr_active_slave) {
                        SLAVE_TLB_INFO(slave).load =
                              bond_info->unbalanced_load /
                                    BOND_TLB_REBALANCE_INTERVAL;
                        bond_info->unbalanced_load = 0;
                  }
            }

            read_unlock(&bond->curr_slave_lock);

            bond_info->tx_rebalance_counter = 0;
      }

      /* handle rlb stuff */
      if (bond_info->rlb_enabled) {
            if (bond_info->primary_is_promisc &&
                (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {

                  /*
                   * dev_set_promiscuity requires rtnl and
                   * nothing else.
                   */
                  read_unlock(&bond->lock);
                  rtnl_lock();

                  bond_info->rlb_promisc_timeout_counter = 0;

                  /* If the primary was set to promiscuous mode
                   * because a slave was disabled then
                   * it can now leave promiscuous mode.
                   */
                  dev_set_promiscuity(bond->curr_active_slave->dev, -1);
                  bond_info->primary_is_promisc = 0;

                  rtnl_unlock();
                  read_lock(&bond->lock);
            }

            if (bond_info->rlb_rebalance) {
                  bond_info->rlb_rebalance = 0;
                  rlb_rebalance(bond);
            }

            /* check if clients need updating */
            if (bond_info->rx_ntt) {
                  if (bond_info->rlb_update_delay_counter) {
                        --bond_info->rlb_update_delay_counter;
                  } else {
                        rlb_update_rx_clients(bond);
                        if (bond_info->rlb_update_retry_counter) {
                              --bond_info->rlb_update_retry_counter;
                        } else {
                              bond_info->rx_ntt = 0;
                        }
                  }
            }
      }

re_arm:
      queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);
out:
      read_unlock(&bond->lock);
}

/* assumption: called before the slave is attached to the bond
 * and not locked by the bond lock
 */
int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
{
      int res;

      res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr,
                             bond->alb_info.rlb_enabled);
      if (res) {
            return res;
      }

      /* caller must hold the bond lock for write since the mac addresses
       * are compared and may be swapped.
       */
      read_lock(&bond->lock);

      res = alb_handle_addr_collision_on_attach(bond, slave);

      read_unlock(&bond->lock);

      if (res) {
            return res;
      }

      tlb_init_slave(slave);

      /* order a rebalance ASAP */
      bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;

      if (bond->alb_info.rlb_enabled) {
            bond->alb_info.rlb_rebalance = 1;
      }

      return 0;
}

/*
 * Remove slave from tlb and rlb hash tables, and fix up MAC addresses
 * if necessary.
 *
 * Caller must hold RTNL and no other locks
 */
void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
{
      if (bond->slave_cnt > 1) {
            alb_change_hw_addr_on_detach(bond, slave);
      }

      tlb_clear_slave(bond, slave, 0);

      if (bond->alb_info.rlb_enabled) {
            bond->alb_info.next_rx_slave = NULL;
            rlb_clear_slave(bond, slave);
      }
}

/* Caller must hold bond lock for read */
void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
{
      struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

      if (link == BOND_LINK_DOWN) {
            tlb_clear_slave(bond, slave, 0);
            if (bond->alb_info.rlb_enabled) {
                  rlb_clear_slave(bond, slave);
            }
      } else if (link == BOND_LINK_UP) {
            /* order a rebalance ASAP */
            bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
            if (bond->alb_info.rlb_enabled) {
                  bond->alb_info.rlb_rebalance = 1;
                  /* If the updelay module parameter is smaller than the
                   * forwarding delay of the switch the rebalance will
                   * not work because the rebalance arp replies will
                   * not be forwarded to the clients..
                   */
            }
      }
}

/**
 * bond_alb_handle_active_change - assign new curr_active_slave
 * @bond: our bonding struct
 * @new_slave: new slave to assign
 *
 * Set the bond->curr_active_slave to @new_slave and handle
 * mac address swapping and promiscuity changes as needed.
 *
 * If new_slave is NULL, caller must hold curr_slave_lock or
 * bond->lock for write.
 *
 * If new_slave is not NULL, caller must hold RTNL, bond->lock for
 * read and curr_slave_lock for write.  Processing here may sleep, so
 * no other locks may be held.
 */
void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
{
      struct slave *swap_slave;
      int i;

      if (bond->curr_active_slave == new_slave) {
            return;
      }

      if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
            dev_set_promiscuity(bond->curr_active_slave->dev, -1);
            bond->alb_info.primary_is_promisc = 0;
            bond->alb_info.rlb_promisc_timeout_counter = 0;
      }

      swap_slave = bond->curr_active_slave;
      bond->curr_active_slave = new_slave;

      if (!new_slave || (bond->slave_cnt == 0)) {
            return;
      }

      /* set the new curr_active_slave to the bonds mac address
       * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
       */
      if (!swap_slave) {
            struct slave *tmp_slave;
            /* find slave that is holding the bond's mac address */
            bond_for_each_slave(bond, tmp_slave, i) {
                  if (!memcmp(tmp_slave->dev->dev_addr,
                            bond->dev->dev_addr, ETH_ALEN)) {
                        swap_slave = tmp_slave;
                        break;
                  }
            }
      }

      /*
       * Arrange for swap_slave and new_slave to temporarily be
       * ignored so we can mess with their MAC addresses without
       * fear of interference from transmit activity.
       */
      if (swap_slave) {
            tlb_clear_slave(bond, swap_slave, 1);
      }
      tlb_clear_slave(bond, new_slave, 1);

      write_unlock_bh(&bond->curr_slave_lock);
      read_unlock(&bond->lock);

      ASSERT_RTNL();

      /* curr_active_slave must be set before calling alb_swap_mac_addr */
      if (swap_slave) {
            /* swap mac address */
            alb_swap_mac_addr(bond, swap_slave, new_slave);
      } else {
            /* set the new_slave to the bond mac address */
            alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr,
                               bond->alb_info.rlb_enabled);
      }

      if (swap_slave) {
            alb_fasten_mac_swap(bond, swap_slave, new_slave);
            read_lock(&bond->lock);
      } else {
            read_lock(&bond->lock);
            alb_send_learning_packets(new_slave, bond->dev->dev_addr);
      }

      write_lock_bh(&bond->curr_slave_lock);
}

/*
 * Called with RTNL
 */
int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
{
      struct bonding *bond = bond_dev->priv;
      struct sockaddr *sa = addr;
      struct slave *slave, *swap_slave;
      int res;
      int i;

      if (!is_valid_ether_addr(sa->sa_data)) {
            return -EADDRNOTAVAIL;
      }

      res = alb_set_mac_address(bond, addr);
      if (res) {
            return res;
      }

      memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);

      /* If there is no curr_active_slave there is nothing else to do.
       * Otherwise we'll need to pass the new address to it and handle
       * duplications.
       */
      if (!bond->curr_active_slave) {
            return 0;
      }

      swap_slave = NULL;

      bond_for_each_slave(bond, slave, i) {
            if (!memcmp(slave->dev->dev_addr, bond_dev->dev_addr, ETH_ALEN)) {
                  swap_slave = slave;
                  break;
            }
      }

      write_unlock_bh(&bond->curr_slave_lock);
      read_unlock(&bond->lock);

      if (swap_slave) {
            alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
            alb_fasten_mac_swap(bond, swap_slave, bond->curr_active_slave);
      } else {
            alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
                               bond->alb_info.rlb_enabled);

            alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
            if (bond->alb_info.rlb_enabled) {
                  /* inform clients mac address has changed */
                  rlb_req_update_slave_clients(bond, bond->curr_active_slave);
            }
      }

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

      return 0;
}

void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
{
      if (bond->alb_info.current_alb_vlan &&
          (bond->alb_info.current_alb_vlan->vlan_id == vlan_id)) {
            bond->alb_info.current_alb_vlan = NULL;
      }

      if (bond->alb_info.rlb_enabled) {
            rlb_clear_vlan(bond, vlan_id);
      }
}


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