Merge tag 'batman-adv-for-davem' of git://git.open-mesh.org/linux-merge

[~andy/linux] / drivers / net / bonding / bond_3ad.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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/skbuff.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
#include <linux/if_bonding.h>
#include <linux/pkt_sched.h>
#include <net/net_namespace.h>
#include "bonding.h"
#include "bond_3ad.h"

/* General definitions */
#define AD_SHORT_TIMEOUT           1
#define AD_LONG_TIMEOUT            0
#define AD_STANDBY                 0x2
#define AD_MAX_TX_IN_SECOND        3
#define AD_COLLECTOR_MAX_DELAY     0

/* Timer definitions (43.4.4 in the 802.3ad standard) */
#define AD_FAST_PERIODIC_TIME      1
#define AD_SLOW_PERIODIC_TIME      30
#define AD_SHORT_TIMEOUT_TIME      (3*AD_FAST_PERIODIC_TIME)
#define AD_LONG_TIMEOUT_TIME       (3*AD_SLOW_PERIODIC_TIME)
#define AD_CHURN_DETECTION_TIME    60
#define AD_AGGREGATE_WAIT_TIME     2

/* Port state definitions (43.4.2.2 in the 802.3ad standard) */
#define AD_STATE_LACP_ACTIVITY   0x1
#define AD_STATE_LACP_TIMEOUT    0x2
#define AD_STATE_AGGREGATION     0x4
#define AD_STATE_SYNCHRONIZATION 0x8
#define AD_STATE_COLLECTING      0x10
#define AD_STATE_DISTRIBUTING    0x20
#define AD_STATE_DEFAULTED       0x40
#define AD_STATE_EXPIRED         0x80

/* Port Variables definitions used by the State Machines (43.4.7 in the
 * 802.3ad standard)
 */
#define AD_PORT_BEGIN           0x1
#define AD_PORT_LACP_ENABLED    0x2
#define AD_PORT_ACTOR_CHURN     0x4
#define AD_PORT_PARTNER_CHURN   0x8
#define AD_PORT_READY           0x10
#define AD_PORT_READY_N         0x20
#define AD_PORT_MATCHED         0x40
#define AD_PORT_STANDBY         0x80
#define AD_PORT_SELECTED        0x100
#define AD_PORT_MOVED           0x200

/* Port Key definitions
 * key is determined according to the link speed, duplex and
 * user key (which is yet not supported)
 * --------------------------------------------------------------
 * Port key :   | User key      | Speed         | Duplex        |
 * --------------------------------------------------------------
 * 16             6               1               0
 */
#define  AD_DUPLEX_KEY_BITS    0x1
#define  AD_SPEED_KEY_BITS     0x3E
#define  AD_USER_KEY_BITS      0xFFC0

#define     AD_LINK_SPEED_BITMASK_1MBPS       0x1
#define     AD_LINK_SPEED_BITMASK_10MBPS      0x2
#define     AD_LINK_SPEED_BITMASK_100MBPS     0x4
#define     AD_LINK_SPEED_BITMASK_1000MBPS    0x8
#define     AD_LINK_SPEED_BITMASK_10000MBPS   0x10

/* compare MAC addresses */
#define MAC_ADDRESS_EQUAL(A, B) \
        ether_addr_equal_64bits((const u8 *)A, (const u8 *)B)

static struct mac_addr null_mac_addr = { { 0, 0, 0, 0, 0, 0 } };
static u16 ad_ticks_per_sec;
static const int ad_delta_in_ticks = (AD_TIMER_INTERVAL * HZ) / 1000;

static const u8 lacpdu_mcast_addr[ETH_ALEN] = MULTICAST_LACPDU_ADDR;

/* ================= main 802.3ad protocol functions ================== */
static int ad_lacpdu_send(struct port *port);
static int ad_marker_send(struct port *port, struct bond_marker *marker);
static void ad_mux_machine(struct port *port);
static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port);
static void ad_tx_machine(struct port *port);
static void ad_periodic_machine(struct port *port);
static void ad_port_selection_logic(struct port *port);
static void ad_agg_selection_logic(struct aggregator *aggregator);
static void ad_clear_agg(struct aggregator *aggregator);
static void ad_initialize_agg(struct aggregator *aggregator);
static void ad_initialize_port(struct port *port, int lacp_fast);
static void ad_enable_collecting_distributing(struct port *port);
static void ad_disable_collecting_distributing(struct port *port);
static void ad_marker_info_received(struct bond_marker *marker_info,
                                    struct port *port);
static void ad_marker_response_received(struct bond_marker *marker,
                                        struct port *port);


/* ================= api to bonding and kernel code ================== */

/**
 * __get_bond_by_port - get the port's bonding struct
 * @port: the port we're looking at
 *
 * Return @port's bonding struct, or %NULL if it can't be found.
 */
static inline struct bonding *__get_bond_by_port(struct port *port)
{
        if (port->slave == NULL)
                return NULL;

        return bond_get_bond_by_slave(port->slave);
}

/**
 * __get_first_agg - get the first aggregator in the bond
 * @bond: the bond we're looking at
 *
 * Return the aggregator of the first slave in @bond, or %NULL if it can't be
 * found.
 */
static inline struct aggregator *__get_first_agg(struct port *port)
{
        struct bonding *bond = __get_bond_by_port(port);
        struct slave *first_slave;

        /* If there's no bond for this port, or bond has no slaves */
        if (bond == NULL)
                return NULL;

        rcu_read_lock();
        first_slave = bond_first_slave_rcu(bond);
        rcu_read_unlock();

        return first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL;
}

/**
 * __agg_has_partner - see if we have a partner
 * @agg: the agregator we're looking at
 *
 * Return nonzero if aggregator has a partner (denoted by a non-zero ether
 * address for the partner). Return 0 if not.
 */
static inline int __agg_has_partner(struct aggregator *agg)
{
        return !is_zero_ether_addr(agg->partner_system.mac_addr_value);
}

/**
 * __disable_port - disable the port's slave
 * @port: the port we're looking at
 */
static inline void __disable_port(struct port *port)
{
        bond_set_slave_inactive_flags(port->slave);
}

/**
 * __enable_port - enable the port's slave, if it's up
 * @port: the port we're looking at
 */
static inline void __enable_port(struct port *port)
{
        struct slave *slave = port->slave;

        if ((slave->link == BOND_LINK_UP) && IS_UP(slave->dev))
                bond_set_slave_active_flags(slave);
}

/**
 * __port_is_enabled - check if the port's slave is in active state
 * @port: the port we're looking at
 */
static inline int __port_is_enabled(struct port *port)
{
        return bond_is_active_slave(port->slave);
}

/**
 * __get_agg_selection_mode - get the aggregator selection mode
 * @port: the port we're looking at
 *
 * Get the aggregator selection mode. Can be %STABLE, %BANDWIDTH or %COUNT.
 */
static inline u32 __get_agg_selection_mode(struct port *port)
{
        struct bonding *bond = __get_bond_by_port(port);

        if (bond == NULL)
                return BOND_AD_STABLE;

        return bond->params.ad_select;
}

/**
 * __check_agg_selection_timer - check if the selection timer has expired
 * @port: the port we're looking at
 */
static inline int __check_agg_selection_timer(struct port *port)
{
        struct bonding *bond = __get_bond_by_port(port);

        if (bond == NULL)
                return 0;

        return BOND_AD_INFO(bond).agg_select_timer ? 1 : 0;
}

/**
 * __get_state_machine_lock - lock the port's state machines
 * @port: the port we're looking at
 */
static inline void __get_state_machine_lock(struct port *port)
{
        spin_lock_bh(&(SLAVE_AD_INFO(port->slave).state_machine_lock));
}

/**
 * __release_state_machine_lock - unlock the port's state machines
 * @port: the port we're looking at
 */
static inline void __release_state_machine_lock(struct port *port)
{
        spin_unlock_bh(&(SLAVE_AD_INFO(port->slave).state_machine_lock));
}

/**
 * __get_link_speed - get a port's speed
 * @port: the port we're looking at
 *
 * Return @port's speed in 802.3ad bitmask format. i.e. one of:
 *     0,
 *     %AD_LINK_SPEED_BITMASK_10MBPS,
 *     %AD_LINK_SPEED_BITMASK_100MBPS,
 *     %AD_LINK_SPEED_BITMASK_1000MBPS,
 *     %AD_LINK_SPEED_BITMASK_10000MBPS
 */
static u16 __get_link_speed(struct port *port)
{
        struct slave *slave = port->slave;
        u16 speed;

        /* this if covers only a special case: when the configuration starts
         * with link down, it sets the speed to 0.
         * This is done in spite of the fact that the e100 driver reports 0
         * to be compatible with MVT in the future.
         */
        if (slave->link != BOND_LINK_UP)
                speed = 0;
        else {
                switch (slave->speed) {
                case SPEED_10:
                        speed = AD_LINK_SPEED_BITMASK_10MBPS;
                        break;

                case SPEED_100:
                        speed = AD_LINK_SPEED_BITMASK_100MBPS;
                        break;

                case SPEED_1000:
                        speed = AD_LINK_SPEED_BITMASK_1000MBPS;
                        break;

                case SPEED_10000:
                        speed = AD_LINK_SPEED_BITMASK_10000MBPS;
                        break;

                default:
                        /* unknown speed value from ethtool. shouldn't happen */
                        speed = 0;
                        break;
                }
        }

        pr_debug("Port %d Received link speed %d update from adapter\n",
                 port->actor_port_number, speed);
        return speed;
}

/**
 * __get_duplex - get a port's duplex
 * @port: the port we're looking at
 *
 * Return @port's duplex in 802.3ad bitmask format. i.e.:
 *     0x01 if in full duplex
 *     0x00 otherwise
 */
static u8 __get_duplex(struct port *port)
{
        struct slave *slave = port->slave;

        u8 retval;

        /* handling a special case: when the configuration starts with
         * link down, it sets the duplex to 0.
         */
        if (slave->link != BOND_LINK_UP)
                retval = 0x0;
        else {
                switch (slave->duplex) {
                case DUPLEX_FULL:
                        retval = 0x1;
                        pr_debug("Port %d Received status full duplex update from adapter\n",
                                 port->actor_port_number);
                        break;
                case DUPLEX_HALF:
                default:
                        retval = 0x0;
                        pr_debug("Port %d Received status NOT full duplex update from adapter\n",
                                 port->actor_port_number);
                        break;
                }
        }
        return retval;
}

/**
 * __initialize_port_locks - initialize a port's STATE machine spinlock
 * @port: the slave of the port we're looking at
 */
static inline void __initialize_port_locks(struct slave *slave)
{
        /* make sure it isn't called twice */
        spin_lock_init(&(SLAVE_AD_INFO(slave).state_machine_lock));
}

/* Conversions */

/**
 * __ad_timer_to_ticks - convert a given timer type to AD module ticks
 * @timer_type: which timer to operate
 * @par: timer parameter. see below
 *
 * If @timer_type is %current_while_timer, @par indicates long/short timer.
 * If @timer_type is %periodic_timer, @par is one of %FAST_PERIODIC_TIME,
 *                                                   %SLOW_PERIODIC_TIME.
 */
static u16 __ad_timer_to_ticks(u16 timer_type, u16 par)
{
        u16 retval = 0; /* to silence the compiler */

        switch (timer_type) {
        case AD_CURRENT_WHILE_TIMER:    /* for rx machine usage */
                if (par)
                        retval = (AD_SHORT_TIMEOUT_TIME*ad_ticks_per_sec);
                else
                        retval = (AD_LONG_TIMEOUT_TIME*ad_ticks_per_sec);
                break;
        case AD_ACTOR_CHURN_TIMER:      /* for local churn machine */
                retval = (AD_CHURN_DETECTION_TIME*ad_ticks_per_sec);
                break;
        case AD_PERIODIC_TIMER:         /* for periodic machine */
                retval = (par*ad_ticks_per_sec); /* long timeout */
                break;
        case AD_PARTNER_CHURN_TIMER:    /* for remote churn machine */
                retval = (AD_CHURN_DETECTION_TIME*ad_ticks_per_sec);
                break;
        case AD_WAIT_WHILE_TIMER:       /* for selection machine */
                retval = (AD_AGGREGATE_WAIT_TIME*ad_ticks_per_sec);
                break;
        }

        return retval;
}


/* ================= ad_rx_machine helper functions ================== */

/**
 * __choose_matched - update a port's matched variable from a received lacpdu
 * @lacpdu: the lacpdu we've received
 * @port: the port we're looking at
 *
 * Update the value of the matched variable, using parameter values from a
 * newly received lacpdu. Parameter values for the partner carried in the
 * received PDU are compared with the corresponding operational parameter
 * values for the actor. Matched is set to TRUE if all of these parameters
 * match and the PDU parameter partner_state.aggregation has the same value as
 * actor_oper_port_state.aggregation and lacp will actively maintain the link
 * in the aggregation. Matched is also set to TRUE if the value of
 * actor_state.aggregation in the received PDU is set to FALSE, i.e., indicates
 * an individual link and lacp will actively maintain the link. Otherwise,
 * matched is set to FALSE. LACP is considered to be actively maintaining the
 * link if either the PDU's actor_state.lacp_activity variable is TRUE or both
 * the actor's actor_oper_port_state.lacp_activity and the PDU's
 * partner_state.lacp_activity variables are TRUE.
 *
 * Note: the AD_PORT_MATCHED "variable" is not specified by 802.3ad; it is
 * used here to implement the language from 802.3ad 43.4.9 that requires
 * recordPDU to "match" the LACPDU parameters to the stored values.
 */
static void __choose_matched(struct lacpdu *lacpdu, struct port *port)
{
        /* check if all parameters are alike
         * or this is individual link(aggregation == FALSE)
         * then update the state machine Matched variable.
         */
        if (((ntohs(lacpdu->partner_port) == port->actor_port_number) &&
             (ntohs(lacpdu->partner_port_priority) == port->actor_port_priority) &&
             MAC_ADDRESS_EQUAL(&(lacpdu->partner_system), &(port->actor_system)) &&
             (ntohs(lacpdu->partner_system_priority) == port->actor_system_priority) &&
             (ntohs(lacpdu->partner_key) == port->actor_oper_port_key) &&
             ((lacpdu->partner_state & AD_STATE_AGGREGATION) == (port->actor_oper_port_state & AD_STATE_AGGREGATION))) ||
            ((lacpdu->actor_state & AD_STATE_AGGREGATION) == 0)
                ) {
                port->sm_vars |= AD_PORT_MATCHED;
        } else {
                port->sm_vars &= ~AD_PORT_MATCHED;
        }
}

/**
 * __record_pdu - record parameters from a received lacpdu
 * @lacpdu: the lacpdu we've received
 * @port: the port we're looking at
 *
 * Record the parameter values for the Actor carried in a received lacpdu as
 * the current partner operational parameter values and sets
 * actor_oper_port_state.defaulted to FALSE.
 */
static void __record_pdu(struct lacpdu *lacpdu, struct port *port)
{
        if (lacpdu && port) {
                struct port_params *partner = &port->partner_oper;

                __choose_matched(lacpdu, port);
                /* record the new parameter values for the partner
                 * operational
                 */
                partner->port_number = ntohs(lacpdu->actor_port);
                partner->port_priority = ntohs(lacpdu->actor_port_priority);
                partner->system = lacpdu->actor_system;
                partner->system_priority = ntohs(lacpdu->actor_system_priority);
                partner->key = ntohs(lacpdu->actor_key);
                partner->port_state = lacpdu->actor_state;

                /* set actor_oper_port_state.defaulted to FALSE */
                port->actor_oper_port_state &= ~AD_STATE_DEFAULTED;

                /* set the partner sync. to on if the partner is sync,
                 * and the port is matched
                 */
                if ((port->sm_vars & AD_PORT_MATCHED)
                    && (lacpdu->actor_state & AD_STATE_SYNCHRONIZATION))
                        partner->port_state |= AD_STATE_SYNCHRONIZATION;
                else
                        partner->port_state &= ~AD_STATE_SYNCHRONIZATION;
        }
}

/**
 * __record_default - record default parameters
 * @port: the port we're looking at
 *
 * This function records the default parameter values for the partner carried
 * in the Partner Admin parameters as the current partner operational parameter
 * values and sets actor_oper_port_state.defaulted to TRUE.
 */
static void __record_default(struct port *port)
{
        if (port) {
                /* record the partner admin parameters */
                memcpy(&port->partner_oper, &port->partner_admin,
                       sizeof(struct port_params));

                /* set actor_oper_port_state.defaulted to true */
                port->actor_oper_port_state |= AD_STATE_DEFAULTED;
        }
}

/**
 * __update_selected - update a port's Selected variable from a received lacpdu
 * @lacpdu: the lacpdu we've received
 * @port: the port we're looking at
 *
 * Update the value of the selected variable, using parameter values from a
 * newly received lacpdu. The parameter values for the Actor carried in the
 * received PDU are compared with the corresponding operational parameter
 * values for the ports partner. If one or more of the comparisons shows that
 * the value(s) received in the PDU differ from the current operational values,
 * then selected is set to FALSE and actor_oper_port_state.synchronization is
 * set to out_of_sync. Otherwise, selected remains unchanged.
 */
static void __update_selected(struct lacpdu *lacpdu, struct port *port)
{
        if (lacpdu && port) {
                const struct port_params *partner = &port->partner_oper;

                /* check if any parameter is different then
                 * update the state machine selected variable.
                 */
                if (ntohs(lacpdu->actor_port) != partner->port_number ||
                    ntohs(lacpdu->actor_port_priority) != partner->port_priority ||
                    !MAC_ADDRESS_EQUAL(&lacpdu->actor_system, &partner->system) ||
                    ntohs(lacpdu->actor_system_priority) != partner->system_priority ||
                    ntohs(lacpdu->actor_key) != partner->key ||
                    (lacpdu->actor_state & AD_STATE_AGGREGATION) != (partner->port_state & AD_STATE_AGGREGATION)) {
                        port->sm_vars &= ~AD_PORT_SELECTED;
                }
        }
}

/**
 * __update_default_selected - update a port's Selected variable from Partner
 * @port: the port we're looking at
 *
 * This function updates the value of the selected variable, using the partner
 * administrative parameter values. The administrative values are compared with
 * the corresponding operational parameter values for the partner. If one or
 * more of the comparisons shows that the administrative value(s) differ from
 * the current operational values, then Selected is set to FALSE and
 * actor_oper_port_state.synchronization is set to OUT_OF_SYNC. Otherwise,
 * Selected remains unchanged.
 */
static void __update_default_selected(struct port *port)
{
        if (port) {
                const struct port_params *admin = &port->partner_admin;
                const struct port_params *oper = &port->partner_oper;

                /* check if any parameter is different then
                 * update the state machine selected variable.
                 */
                if (admin->port_number != oper->port_number ||
                    admin->port_priority != oper->port_priority ||
                    !MAC_ADDRESS_EQUAL(&admin->system, &oper->system) ||
                    admin->system_priority != oper->system_priority ||
                    admin->key != oper->key ||
                    (admin->port_state & AD_STATE_AGGREGATION)
                        != (oper->port_state & AD_STATE_AGGREGATION)) {
                        port->sm_vars &= ~AD_PORT_SELECTED;
                }
        }
}

/**
 * __update_ntt - update a port's ntt variable from a received lacpdu
 * @lacpdu: the lacpdu we've received
 * @port: the port we're looking at
 *
 * Updates the value of the ntt variable, using parameter values from a newly
 * received lacpdu. The parameter values for the partner carried in the
 * received PDU are compared with the corresponding operational parameter
 * values for the Actor. If one or more of the comparisons shows that the
 * value(s) received in the PDU differ from the current operational values,
 * then ntt is set to TRUE. Otherwise, ntt remains unchanged.
 */
static void __update_ntt(struct lacpdu *lacpdu, struct port *port)
{
        /* validate lacpdu and port */
        if (lacpdu && port) {
                /* check if any parameter is different then
                 * update the port->ntt.
                 */
                if ((ntohs(lacpdu->partner_port) != port->actor_port_number) ||
                    (ntohs(lacpdu->partner_port_priority) != port->actor_port_priority) ||
                    !MAC_ADDRESS_EQUAL(&(lacpdu->partner_system), &(port->actor_system)) ||
                    (ntohs(lacpdu->partner_system_priority) != port->actor_system_priority) ||
                    (ntohs(lacpdu->partner_key) != port->actor_oper_port_key) ||
                    ((lacpdu->partner_state & AD_STATE_LACP_ACTIVITY) != (port->actor_oper_port_state & AD_STATE_LACP_ACTIVITY)) ||
                    ((lacpdu->partner_state & AD_STATE_LACP_TIMEOUT) != (port->actor_oper_port_state & AD_STATE_LACP_TIMEOUT)) ||
                    ((lacpdu->partner_state & AD_STATE_SYNCHRONIZATION) != (port->actor_oper_port_state & AD_STATE_SYNCHRONIZATION)) ||
                    ((lacpdu->partner_state & AD_STATE_AGGREGATION) != (port->actor_oper_port_state & AD_STATE_AGGREGATION))
                   ) {
                        port->ntt = true;
                }
        }
}

/**
 * __agg_ports_are_ready - check if all ports in an aggregator are ready
 * @aggregator: the aggregator we're looking at
 *
 */
static int __agg_ports_are_ready(struct aggregator *aggregator)
{
        struct port *port;
        int retval = 1;

        if (aggregator) {
                /* scan all ports in this aggregator to verfy if they are
                 * all ready.
                 */
                for (port = aggregator->lag_ports;
                     port;
                     port = port->next_port_in_aggregator) {
                        if (!(port->sm_vars & AD_PORT_READY_N)) {
                                retval = 0;
                                break;
                        }
                }
        }

        return retval;
}

/**
 * __set_agg_ports_ready - set value of Ready bit in all ports of an aggregator
 * @aggregator: the aggregator we're looking at
 * @val: Should the ports' ready bit be set on or off
 *
 */
static void __set_agg_ports_ready(struct aggregator *aggregator, int val)
{
        struct port *port;

        for (port = aggregator->lag_ports; port;
             port = port->next_port_in_aggregator) {
                if (val)
                        port->sm_vars |= AD_PORT_READY;
                else
                        port->sm_vars &= ~AD_PORT_READY;
        }
}

/**
 * __get_agg_bandwidth - get the total bandwidth of an aggregator
 * @aggregator: the aggregator we're looking at
 *
 */
static u32 __get_agg_bandwidth(struct aggregator *aggregator)
{
        u32 bandwidth = 0;

        if (aggregator->num_of_ports) {
                switch (__get_link_speed(aggregator->lag_ports)) {
                case AD_LINK_SPEED_BITMASK_1MBPS:
                        bandwidth = aggregator->num_of_ports;
                        break;
                case AD_LINK_SPEED_BITMASK_10MBPS:
                        bandwidth = aggregator->num_of_ports * 10;
                        break;
                case AD_LINK_SPEED_BITMASK_100MBPS:
                        bandwidth = aggregator->num_of_ports * 100;
                        break;
                case AD_LINK_SPEED_BITMASK_1000MBPS:
                        bandwidth = aggregator->num_of_ports * 1000;
                        break;
                case AD_LINK_SPEED_BITMASK_10000MBPS:
                        bandwidth = aggregator->num_of_ports * 10000;
                        break;
                default:
                        bandwidth = 0; /* to silence the compiler */
                }
        }
        return bandwidth;
}

/**
 * __get_active_agg - get the current active aggregator
 * @aggregator: the aggregator we're looking at
 */
static struct aggregator *__get_active_agg(struct aggregator *aggregator)
{
        struct bonding *bond = aggregator->slave->bond;
        struct list_head *iter;
        struct slave *slave;

        rcu_read_lock();
        bond_for_each_slave_rcu(bond, slave, iter)
                if (SLAVE_AD_INFO(slave).aggregator.is_active) {
                        rcu_read_unlock();
                        return &(SLAVE_AD_INFO(slave).aggregator);
                }
        rcu_read_unlock();

        return NULL;
}

/**
 * __update_lacpdu_from_port - update a port's lacpdu fields
 * @port: the port we're looking at
 */
static inline void __update_lacpdu_from_port(struct port *port)
{
        struct lacpdu *lacpdu = &port->lacpdu;
        const struct port_params *partner = &port->partner_oper;

        /* update current actual Actor parameters
         * lacpdu->subtype                   initialized
         * lacpdu->version_number            initialized
         * lacpdu->tlv_type_actor_info       initialized
         * lacpdu->actor_information_length  initialized
         */

        lacpdu->actor_system_priority = htons(port->actor_system_priority);
        lacpdu->actor_system = port->actor_system;
        lacpdu->actor_key = htons(port->actor_oper_port_key);
        lacpdu->actor_port_priority = htons(port->actor_port_priority);
        lacpdu->actor_port = htons(port->actor_port_number);
        lacpdu->actor_state = port->actor_oper_port_state;

        /* lacpdu->reserved_3_1              initialized
         * lacpdu->tlv_type_partner_info     initialized
         * lacpdu->partner_information_length initialized
         */

        lacpdu->partner_system_priority = htons(partner->system_priority);
        lacpdu->partner_system = partner->system;
        lacpdu->partner_key = htons(partner->key);
        lacpdu->partner_port_priority = htons(partner->port_priority);
        lacpdu->partner_port = htons(partner->port_number);
        lacpdu->partner_state = partner->port_state;

        /* lacpdu->reserved_3_2              initialized
         * lacpdu->tlv_type_collector_info   initialized
         * lacpdu->collector_information_length initialized
         * collector_max_delay                initialized
         * reserved_12[12]                   initialized
         * tlv_type_terminator               initialized
         * terminator_length                 initialized
         * reserved_50[50]                   initialized
         */
}

/* ================= main 802.3ad protocol code ========================= */

/**
 * ad_lacpdu_send - send out a lacpdu packet on a given port
 * @port: the port we're looking at
 *
 * Returns:   0 on success
 *          < 0 on error
 */
static int ad_lacpdu_send(struct port *port)
{
        struct slave *slave = port->slave;
        struct sk_buff *skb;
        struct lacpdu_header *lacpdu_header;
        int length = sizeof(struct lacpdu_header);

        skb = dev_alloc_skb(length);
        if (!skb)
                return -ENOMEM;

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

        lacpdu_header = (struct lacpdu_header *)skb_put(skb, length);

        memcpy(lacpdu_header->hdr.h_dest, lacpdu_mcast_addr, ETH_ALEN);
        /* Note: source address is set to be the member's PERMANENT address,
         * because we use it to identify loopback lacpdus in receive.
         */
        memcpy(lacpdu_header->hdr.h_source, slave->perm_hwaddr, ETH_ALEN);
        lacpdu_header->hdr.h_proto = PKT_TYPE_LACPDU;

        lacpdu_header->lacpdu = port->lacpdu;

        dev_queue_xmit(skb);

        return 0;
}

/**
 * ad_marker_send - send marker information/response on a given port
 * @port: the port we're looking at
 * @marker: marker data to send
 *
 * Returns:   0 on success
 *          < 0 on error
 */
static int ad_marker_send(struct port *port, struct bond_marker *marker)
{
        struct slave *slave = port->slave;
        struct sk_buff *skb;
        struct bond_marker_header *marker_header;
        int length = sizeof(struct bond_marker_header);

        skb = dev_alloc_skb(length + 16);
        if (!skb)
                return -ENOMEM;

        skb_reserve(skb, 16);

        skb->dev = slave->dev;
        skb_reset_mac_header(skb);
        skb->network_header = skb->mac_header + ETH_HLEN;
        skb->protocol = PKT_TYPE_LACPDU;

        marker_header = (struct bond_marker_header *)skb_put(skb, length);

        memcpy(marker_header->hdr.h_dest, lacpdu_mcast_addr, ETH_ALEN);
        /* Note: source address is set to be the member's PERMANENT address,
         * because we use it to identify loopback MARKERs in receive.
         */
        memcpy(marker_header->hdr.h_source, slave->perm_hwaddr, ETH_ALEN);
        marker_header->hdr.h_proto = PKT_TYPE_LACPDU;

        marker_header->marker = *marker;

        dev_queue_xmit(skb);

        return 0;
}

/**
 * ad_mux_machine - handle a port's mux state machine
 * @port: the port we're looking at
 */
static void ad_mux_machine(struct port *port)
{
        mux_states_t last_state;

        /* keep current State Machine state to compare later if it was
         * changed
         */
        last_state = port->sm_mux_state;

        if (port->sm_vars & AD_PORT_BEGIN) {
                port->sm_mux_state = AD_MUX_DETACHED;
        } else {
                switch (port->sm_mux_state) {
                case AD_MUX_DETACHED:
                        if ((port->sm_vars & AD_PORT_SELECTED)
                            || (port->sm_vars & AD_PORT_STANDBY))
                                /* if SELECTED or STANDBY */
                                port->sm_mux_state = AD_MUX_WAITING;
                        break;
                case AD_MUX_WAITING:
                        /* if SELECTED == FALSE return to DETACH state */
                        if (!(port->sm_vars & AD_PORT_SELECTED)) {
                                port->sm_vars &= ~AD_PORT_READY_N;
                                /* in order to withhold the Selection Logic to
                                 * check all ports READY_N value every callback
                                 * cycle to update ready variable, we check
                                 * READY_N and update READY here
                                 */
                                __set_agg_ports_ready(port->aggregator, __agg_ports_are_ready(port->aggregator));
                                port->sm_mux_state = AD_MUX_DETACHED;
                                break;
                        }

                        /* check if the wait_while_timer expired */
                        if (port->sm_mux_timer_counter
                            && !(--port->sm_mux_timer_counter))
                                port->sm_vars |= AD_PORT_READY_N;

                        /* in order to withhold the selection logic to check
                         * all ports READY_N value every callback cycle to
                         * update ready variable, we check READY_N and update
                         * READY here
                         */
                        __set_agg_ports_ready(port->aggregator, __agg_ports_are_ready(port->aggregator));

                        /* if the wait_while_timer expired, and the port is
                         * in READY state, move to ATTACHED state
                         */
                        if ((port->sm_vars & AD_PORT_READY)
                            && !port->sm_mux_timer_counter)
                                port->sm_mux_state = AD_MUX_ATTACHED;
                        break;
                case AD_MUX_ATTACHED:
                        /* check also if agg_select_timer expired (so the
                         * edable port will take place only after this timer)
                         */
                        if ((port->sm_vars & AD_PORT_SELECTED) &&
                            (port->partner_oper.port_state & AD_STATE_SYNCHRONIZATION) &&
                            !__check_agg_selection_timer(port)) {
                                port->sm_mux_state = AD_MUX_COLLECTING_DISTRIBUTING;
                        } else if (!(port->sm_vars & AD_PORT_SELECTED) ||
                                   (port->sm_vars & AD_PORT_STANDBY)) {
                                /* if UNSELECTED or STANDBY */
                                port->sm_vars &= ~AD_PORT_READY_N;
                                /* in order to withhold the selection logic to
                                 * check all ports READY_N value every callback
                                 * cycle to update ready variable, we check
                                 * READY_N and update READY here
                                 */
                                __set_agg_ports_ready(port->aggregator, __agg_ports_are_ready(port->aggregator));
                                port->sm_mux_state = AD_MUX_DETACHED;
                        }
                        break;
                case AD_MUX_COLLECTING_DISTRIBUTING:
                        if (!(port->sm_vars & AD_PORT_SELECTED) ||
                            (port->sm_vars & AD_PORT_STANDBY) ||
                            !(port->partner_oper.port_state & AD_STATE_SYNCHRONIZATION)) {
                                port->sm_mux_state = AD_MUX_ATTACHED;
                        } else {
                                /* if port state hasn't changed make
                                 * sure that a collecting distributing
                                 * port in an active aggregator is enabled
                                 */
                                if (port->aggregator &&
                                    port->aggregator->is_active &&
                                    !__port_is_enabled(port)) {

                                        __enable_port(port);
                                }
                        }
                        break;
                default:
                        break;
                }
        }

        /* check if the state machine was changed */
        if (port->sm_mux_state != last_state) {
                pr_debug("Mux Machine: Port=%d, Last State=%d, Curr State=%d\n",
                         port->actor_port_number, last_state,
                         port->sm_mux_state);
                switch (port->sm_mux_state) {
                case AD_MUX_DETACHED:
                        port->actor_oper_port_state &= ~AD_STATE_SYNCHRONIZATION;
                        ad_disable_collecting_distributing(port);
                        port->actor_oper_port_state &= ~AD_STATE_COLLECTING;
                        port->actor_oper_port_state &= ~AD_STATE_DISTRIBUTING;
                        port->ntt = true;
                        break;
                case AD_MUX_WAITING:
                        port->sm_mux_timer_counter = __ad_timer_to_ticks(AD_WAIT_WHILE_TIMER, 0);
                        break;
                case AD_MUX_ATTACHED:
                        port->actor_oper_port_state |= AD_STATE_SYNCHRONIZATION;
                        port->actor_oper_port_state &= ~AD_STATE_COLLECTING;
                        port->actor_oper_port_state &= ~AD_STATE_DISTRIBUTING;
                        ad_disable_collecting_distributing(port);
                        port->ntt = true;
                        break;
                case AD_MUX_COLLECTING_DISTRIBUTING:
                        port->actor_oper_port_state |= AD_STATE_COLLECTING;
                        port->actor_oper_port_state |= AD_STATE_DISTRIBUTING;
                        ad_enable_collecting_distributing(port);
                        port->ntt = true;
                        break;
                default:
                        break;
                }
        }
}

/**
 * ad_rx_machine - handle a port's rx State Machine
 * @lacpdu: the lacpdu we've received
 * @port: the port we're looking at
 *
 * If lacpdu arrived, stop previous timer (if exists) and set the next state as
 * CURRENT. If timer expired set the state machine in the proper state.
 * In other cases, this function checks if we need to switch to other state.
 */
static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port)
{
        rx_states_t last_state;

        /* keep current State Machine state to compare later if it was
         * changed
         */
        last_state = port->sm_rx_state;

        /* check if state machine should change state */

        /* first, check if port was reinitialized */
        if (port->sm_vars & AD_PORT_BEGIN)
                port->sm_rx_state = AD_RX_INITIALIZE;
        /* check if port is not enabled */
        else if (!(port->sm_vars & AD_PORT_BEGIN)
                 && !port->is_enabled && !(port->sm_vars & AD_PORT_MOVED))
                port->sm_rx_state = AD_RX_PORT_DISABLED;
        /* check if new lacpdu arrived */
        else if (lacpdu && ((port->sm_rx_state == AD_RX_EXPIRED) ||
                 (port->sm_rx_state == AD_RX_DEFAULTED) ||
                 (port->sm_rx_state == AD_RX_CURRENT))) {
                port->sm_rx_timer_counter = 0;
                port->sm_rx_state = AD_RX_CURRENT;
        } else {
                /* if timer is on, and if it is expired */
                if (port->sm_rx_timer_counter &&
                    !(--port->sm_rx_timer_counter)) {
                        switch (port->sm_rx_state) {
                        case AD_RX_EXPIRED:
                                port->sm_rx_state = AD_RX_DEFAULTED;
                                break;
                        case AD_RX_CURRENT:
                                port->sm_rx_state = AD_RX_EXPIRED;
                                break;
                        default:
                                break;
                        }
                } else {
                        /* if no lacpdu arrived and no timer is on */
                        switch (port->sm_rx_state) {
                        case AD_RX_PORT_DISABLED:
                                if (port->sm_vars & AD_PORT_MOVED)
                                        port->sm_rx_state = AD_RX_INITIALIZE;
                                else if (port->is_enabled
                                         && (port->sm_vars
                                             & AD_PORT_LACP_ENABLED))
                                        port->sm_rx_state = AD_RX_EXPIRED;
                                else if (port->is_enabled
                                         && ((port->sm_vars
                                              & AD_PORT_LACP_ENABLED) == 0))
                                        port->sm_rx_state = AD_RX_LACP_DISABLED;
                                break;
                        default:
                                break;

                        }
                }
        }

        /* check if the State machine was changed or new lacpdu arrived */
        if ((port->sm_rx_state != last_state) || (lacpdu)) {
                pr_debug("Rx Machine: Port=%d, Last State=%d, Curr State=%d\n",
                         port->actor_port_number, last_state,
                         port->sm_rx_state);
                switch (port->sm_rx_state) {
                case AD_RX_INITIALIZE:
                        if (!(port->actor_oper_port_key & AD_DUPLEX_KEY_BITS))
                                port->sm_vars &= ~AD_PORT_LACP_ENABLED;
                        else
                                port->sm_vars |= AD_PORT_LACP_ENABLED;
                        port->sm_vars &= ~AD_PORT_SELECTED;
                        __record_default(port);
                        port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
                        port->sm_vars &= ~AD_PORT_MOVED;
                        port->sm_rx_state = AD_RX_PORT_DISABLED;

                        /* Fall Through */
                case AD_RX_PORT_DISABLED:
                        port->sm_vars &= ~AD_PORT_MATCHED;
                        break;
                case AD_RX_LACP_DISABLED:
                        port->sm_vars &= ~AD_PORT_SELECTED;
                        __record_default(port);
                        port->partner_oper.port_state &= ~AD_STATE_AGGREGATION;
                        port->sm_vars |= AD_PORT_MATCHED;
                        port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
                        break;
                case AD_RX_EXPIRED:
                        /* Reset of the Synchronization flag (Standard 43.4.12)
                         * This reset cause to disable this port in the
                         * COLLECTING_DISTRIBUTING state of the mux machine in
                         * case of EXPIRED even if LINK_DOWN didn't arrive for
                         * the port.
                         */
                        port->partner_oper.port_state &= ~AD_STATE_SYNCHRONIZATION;
                        port->sm_vars &= ~AD_PORT_MATCHED;
                        port->partner_oper.port_state |= AD_STATE_LACP_ACTIVITY;
                        port->sm_rx_timer_counter = __ad_timer_to_ticks(AD_CURRENT_WHILE_TIMER, (u16)(AD_SHORT_TIMEOUT));
                        port->actor_oper_port_state |= AD_STATE_EXPIRED;
                        break;
                case AD_RX_DEFAULTED:
                        __update_default_selected(port);
                        __record_default(port);
                        port->sm_vars |= AD_PORT_MATCHED;
                        port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
                        break;
                case AD_RX_CURRENT:
                        /* detect loopback situation */
                        if (MAC_ADDRESS_EQUAL(&(lacpdu->actor_system),
                                              &(port->actor_system))) {
                                pr_err("%s: An illegal loopback occurred on adapter (%s).\nCheck the configuration to verify that all adapters are connected to 802.3ad compliant switch ports\n",
                                       port->slave->bond->dev->name,
                                       port->slave->dev->name);
                                return;
                        }
                        __update_selected(lacpdu, port);
                        __update_ntt(lacpdu, port);
                        __record_pdu(lacpdu, port);
                        port->sm_rx_timer_counter = __ad_timer_to_ticks(AD_CURRENT_WHILE_TIMER, (u16)(port->actor_oper_port_state & AD_STATE_LACP_TIMEOUT));
                        port->actor_oper_port_state &= ~AD_STATE_EXPIRED;
                        break;
                default:
                        break;
                }
        }
}

/**
 * ad_tx_machine - handle a port's tx state machine
 * @port: the port we're looking at
 */
static void ad_tx_machine(struct port *port)
{
        /* check if tx timer expired, to verify that we do not send more than
         * 3 packets per second
         */
        if (port->sm_tx_timer_counter && !(--port->sm_tx_timer_counter)) {
                /* check if there is something to send */
                if (port->ntt && (port->sm_vars & AD_PORT_LACP_ENABLED)) {
                        __update_lacpdu_from_port(port);

                        if (ad_lacpdu_send(port) >= 0) {
                                pr_debug("Sent LACPDU on port %d\n",
                                         port->actor_port_number);

                                /* mark ntt as false, so it will not be sent
                                 * again until demanded
                                 */
                                port->ntt = false;
                        }
                }
                /* restart tx timer(to verify that we will not exceed
                 * AD_MAX_TX_IN_SECOND
                 */
                port->sm_tx_timer_counter = ad_ticks_per_sec/AD_MAX_TX_IN_SECOND;
        }
}

/**
 * ad_periodic_machine - handle a port's periodic state machine
 * @port: the port we're looking at
 *
 * Turn ntt flag on priodically to perform periodic transmission of lacpdu's.
 */
static void ad_periodic_machine(struct port *port)
{
        periodic_states_t last_state;

        /* keep current state machine state to compare later if it was changed */
        last_state = port->sm_periodic_state;

        /* check if port was reinitialized */
        if (((port->sm_vars & AD_PORT_BEGIN) || !(port->sm_vars & AD_PORT_LACP_ENABLED) || !port->is_enabled) ||
            (!(port->actor_oper_port_state & AD_STATE_LACP_ACTIVITY) && !(port->partner_oper.port_state & AD_STATE_LACP_ACTIVITY))
           ) {
                port->sm_periodic_state = AD_NO_PERIODIC;
        }
        /* check if state machine should change state */
        else if (port->sm_periodic_timer_counter) {
                /* check if periodic state machine expired */
                if (!(--port->sm_periodic_timer_counter)) {
                        /* if expired then do tx */
                        port->sm_periodic_state = AD_PERIODIC_TX;
                } else {
                        /* If not expired, check if there is some new timeout
                         * parameter from the partner state
                         */
                        switch (port->sm_periodic_state) {
                        case AD_FAST_PERIODIC:
                                if (!(port->partner_oper.port_state
                                      & AD_STATE_LACP_TIMEOUT))
                                        port->sm_periodic_state = AD_SLOW_PERIODIC;
                                break;
                        case AD_SLOW_PERIODIC:
                                if ((port->partner_oper.port_state & AD_STATE_LACP_TIMEOUT)) {
                                        port->sm_periodic_timer_counter = 0;
                                        port->sm_periodic_state = AD_PERIODIC_TX;
                                }
                                break;
                        default:
                                break;
                        }
                }
        } else {
                switch (port->sm_periodic_state) {
                case AD_NO_PERIODIC:
                        port->sm_periodic_state = AD_FAST_PERIODIC;
                        break;
                case AD_PERIODIC_TX:
                        if (!(port->partner_oper.port_state &
                            AD_STATE_LACP_TIMEOUT))
                                port->sm_periodic_state = AD_SLOW_PERIODIC;
                        else
                                port->sm_periodic_state = AD_FAST_PERIODIC;
                        break;
                default:
                        break;
                }
        }

        /* check if the state machine was changed */
        if (port->sm_periodic_state != last_state) {
                pr_debug("Periodic Machine: Port=%d, Last State=%d, Curr State=%d\n",
                         port->actor_port_number, last_state,
                         port->sm_periodic_state);
                switch (port->sm_periodic_state) {
                case AD_NO_PERIODIC:
                        port->sm_periodic_timer_counter = 0;
                        break;
                case AD_FAST_PERIODIC:
                        /* decrement 1 tick we lost in the PERIODIC_TX cycle */
                        port->sm_periodic_timer_counter = __ad_timer_to_ticks(AD_PERIODIC_TIMER, (u16)(AD_FAST_PERIODIC_TIME))-1;
                        break;
                case AD_SLOW_PERIODIC:
                        /* decrement 1 tick we lost in the PERIODIC_TX cycle */
                        port->sm_periodic_timer_counter = __ad_timer_to_ticks(AD_PERIODIC_TIMER, (u16)(AD_SLOW_PERIODIC_TIME))-1;
                        break;
                case AD_PERIODIC_TX:
                        port->ntt = true;
                        break;
                default:
                        break;
                }
        }
}

/**
 * ad_port_selection_logic - select aggregation groups
 * @port: the port we're looking at
 *
 * Select aggregation groups, and assign each port for it's aggregetor. The
 * selection logic is called in the inititalization (after all the handshkes),
 * and after every lacpdu receive (if selected is off).
 */
static void ad_port_selection_logic(struct port *port)
{
        struct aggregator *aggregator, *free_aggregator = NULL, *temp_aggregator;
        struct port *last_port = NULL, *curr_port;
        struct list_head *iter;
        struct bonding *bond;
        struct slave *slave;
        int found = 0;

        /* if the port is already Selected, do nothing */
        if (port->sm_vars & AD_PORT_SELECTED)
                return;

        bond = __get_bond_by_port(port);

        /* if the port is connected to other aggregator, detach it */
        if (port->aggregator) {
                /* detach the port from its former aggregator */
                temp_aggregator = port->aggregator;
                for (curr_port = temp_aggregator->lag_ports; curr_port;
                     last_port = curr_port,
                     curr_port = curr_port->next_port_in_aggregator) {
                        if (curr_port == port) {
                                temp_aggregator->num_of_ports--;
                                /* if it is the first port attached to the
                                 * aggregator
                                 */
                                if (!last_port) {
                                        temp_aggregator->lag_ports =
                                                port->next_port_in_aggregator;
                                } else {
                                        /* not the first port attached to the
                                         * aggregator
                                         */
                                        last_port->next_port_in_aggregator =
                                                port->next_port_in_aggregator;
                                }

                                /* clear the port's relations to this
                                 * aggregator
                                 */
                                port->aggregator = NULL;
                                port->next_port_in_aggregator = NULL;
                                port->actor_port_aggregator_identifier = 0;

                                pr_debug("Port %d left LAG %d\n",
                                         port->actor_port_number,
                                         temp_aggregator->aggregator_identifier);
                                /* if the aggregator is empty, clear its
                                 * parameters, and set it ready to be attached
                                 */
                                if (!temp_aggregator->lag_ports)
                                        ad_clear_agg(temp_aggregator);
                                break;
                        }
                }
                if (!curr_port) {
                        /* meaning: the port was related to an aggregator
                         * but was not on the aggregator port list
                         */
                        pr_warn("%s: Warning: Port %d (on %s) was related to aggregator %d but was not on its port list\n",
                                port->slave->bond->dev->name,
                                port->actor_port_number,
                                port->slave->dev->name,
                                port->aggregator->aggregator_identifier);
                }
        }
        /* search on all aggregators for a suitable aggregator for this port */
        bond_for_each_slave(bond, slave, iter) {
                aggregator = &(SLAVE_AD_INFO(slave).aggregator);

                /* keep a free aggregator for later use(if needed) */
                if (!aggregator->lag_ports) {
                        if (!free_aggregator)
                                free_aggregator = aggregator;
                        continue;
                }
                /* check if current aggregator suits us */
                if (((aggregator->actor_oper_aggregator_key == port->actor_oper_port_key) && /* if all parameters match AND */
                     MAC_ADDRESS_EQUAL(&(aggregator->partner_system), &(port->partner_oper.system)) &&
                     (aggregator->partner_system_priority == port->partner_oper.system_priority) &&
                     (aggregator->partner_oper_aggregator_key == port->partner_oper.key)
                    ) &&
                    ((!MAC_ADDRESS_EQUAL(&(port->partner_oper.system), &(null_mac_addr)) && /* partner answers */
                      !aggregator->is_individual)  /* but is not individual OR */
                    )
                   ) {
                        /* attach to the founded aggregator */
                        port->aggregator = aggregator;
                        port->actor_port_aggregator_identifier =
                                port->aggregator->aggregator_identifier;
                        port->next_port_in_aggregator = aggregator->lag_ports;
                        port->aggregator->num_of_ports++;
                        aggregator->lag_ports = port;
                        pr_debug("Port %d joined LAG %d(existing LAG)\n",
                                 port->actor_port_number,
                                 port->aggregator->aggregator_identifier);

                        /* mark this port as selected */
                        port->sm_vars |= AD_PORT_SELECTED;
                        found = 1;
                        break;
                }
        }

        /* the port couldn't find an aggregator - attach it to a new
         * aggregator
         */
        if (!found) {
                if (free_aggregator) {
                        /* assign port a new aggregator */
                        port->aggregator = free_aggregator;
                        port->actor_port_aggregator_identifier =
                                port->aggregator->aggregator_identifier;

                        /* update the new aggregator's parameters
                         * if port was responsed from the end-user
                         */
                        if (port->actor_oper_port_key & AD_DUPLEX_KEY_BITS)
                                /* if port is full duplex */
                                port->aggregator->is_individual = false;
                        else
                                port->aggregator->is_individual = true;

                        port->aggregator->actor_admin_aggregator_key = port->actor_admin_port_key;
                        port->aggregator->actor_oper_aggregator_key = port->actor_oper_port_key;
                        port->aggregator->partner_system =
                                port->partner_oper.system;
                        port->aggregator->partner_system_priority =
                                port->partner_oper.system_priority;
                        port->aggregator->partner_oper_aggregator_key = port->partner_oper.key;
                        port->aggregator->receive_state = 1;
                        port->aggregator->transmit_state = 1;
                        port->aggregator->lag_ports = port;
                        port->aggregator->num_of_ports++;

                        /* mark this port as selected */
                        port->sm_vars |= AD_PORT_SELECTED;

                        pr_debug("Port %d joined LAG %d(new LAG)\n",
                                 port->actor_port_number,
                                 port->aggregator->aggregator_identifier);
                } else {
                        pr_err("%s: Port %d (on %s) did not find a suitable aggregator\n",
                               port->slave->bond->dev->name,
                               port->actor_port_number, port->slave->dev->name);
                }
        }
        /* if all aggregator's ports are READY_N == TRUE, set ready=TRUE
         * in all aggregator's ports, else set ready=FALSE in all
         * aggregator's ports
         */
        __set_agg_ports_ready(port->aggregator,
                              __agg_ports_are_ready(port->aggregator));

        aggregator = __get_first_agg(port);
        ad_agg_selection_logic(aggregator);
}

/* Decide if "agg" is a better choice for the new active aggregator that
 * the current best, according to the ad_select policy.
 */
static struct aggregator *ad_agg_selection_test(struct aggregator *best,
                                                struct aggregator *curr)
{
        /* 0. If no best, select current.
         *
         * 1. If the current agg is not individual, and the best is
         *    individual, select current.
         *
         * 2. If current agg is individual and the best is not, keep best.
         *
         * 3. Therefore, current and best are both individual or both not
         *    individual, so:
         *
         * 3a. If current agg partner replied, and best agg partner did not,
         *     select current.
         *
         * 3b. If current agg partner did not reply and best agg partner
         *     did reply, keep best.
         *
         * 4.  Therefore, current and best both have partner replies or
         *     both do not, so perform selection policy:
         *
         * BOND_AD_COUNT: Select by count of ports.  If count is equal,
         *     select by bandwidth.
         *
         * BOND_AD_STABLE, BOND_AD_BANDWIDTH: Select by bandwidth.
         */
        if (!best)
                return curr;

        if (!curr->is_individual && best->is_individual)
                return curr;

        if (curr->is_individual && !best->is_individual)
                return best;

        if (__agg_has_partner(curr) && !__agg_has_partner(best))
                return curr;

        if (!__agg_has_partner(curr) && __agg_has_partner(best))
                return best;

        switch (__get_agg_selection_mode(curr->lag_ports)) {
        case BOND_AD_COUNT:
                if (curr->num_of_ports > best->num_of_ports)
                        return curr;

                if (curr->num_of_ports < best->num_of_ports)
                        return best;

                /*FALLTHROUGH*/
        case BOND_AD_STABLE:
        case BOND_AD_BANDWIDTH:
                if (__get_agg_bandwidth(curr) > __get_agg_bandwidth(best))
                        return curr;

                break;

        default:
                pr_warn("%s: Impossible agg select mode %d\n",
                        curr->slave->bond->dev->name,
                        __get_agg_selection_mode(curr->lag_ports));
                break;
        }

        return best;
}

static int agg_device_up(const struct aggregator *agg)
{
        struct port *port = agg->lag_ports;

        if (!port)
                return 0;

        return netif_running(port->slave->dev) &&
               netif_carrier_ok(port->slave->dev);
}

/**
 * ad_agg_selection_logic - select an aggregation group for a team
 * @aggregator: the aggregator we're looking at
 *
 * It is assumed that only one aggregator may be selected for a team.
 *
 * The logic of this function is to select the aggregator according to
 * the ad_select policy:
 *
 * BOND_AD_STABLE: select the aggregator with the most ports attached to
 * it, and to reselect the active aggregator only if the previous
 * aggregator has no more ports related to it.
 *
 * BOND_AD_BANDWIDTH: select the aggregator with the highest total
 * bandwidth, and reselect whenever a link state change takes place or the
 * set of slaves in the bond changes.
 *
 * BOND_AD_COUNT: select the aggregator with largest number of ports
 * (slaves), and reselect whenever a link state change takes place or the
 * set of slaves in the bond changes.
 *
 * FIXME: this function MUST be called with the first agg in the bond, or
 * __get_active_agg() won't work correctly. This function should be better
 * called with the bond itself, and retrieve the first agg from it.
 */
static void ad_agg_selection_logic(struct aggregator *agg)
{
        struct aggregator *best, *active, *origin;
        struct bonding *bond = agg->slave->bond;
        struct list_head *iter;
        struct slave *slave;
        struct port *port;

        origin = agg;
        active = __get_active_agg(agg);
        best = (active && agg_device_up(active)) ? active : NULL;

        rcu_read_lock();
        bond_for_each_slave_rcu(bond, slave, iter) {
                agg = &(SLAVE_AD_INFO(slave).aggregator);

                agg->is_active = 0;

                if (agg->num_of_ports && agg_device_up(agg))
                        best = ad_agg_selection_test(best, agg);
        }

        if (best &&
            __get_agg_selection_mode(best->lag_ports) == BOND_AD_STABLE) {
                /* For the STABLE policy, don't replace the old active
                 * aggregator if it's still active (it has an answering
                 * partner) or if both the best and active don't have an
                 * answering partner.
                 */
                if (active && active->lag_ports &&
                    active->lag_ports->is_enabled &&
                    (__agg_has_partner(active) ||
                     (!__agg_has_partner(active) &&
                     !__agg_has_partner(best)))) {
                        if (!(!active->actor_oper_aggregator_key &&
                              best->actor_oper_aggregator_key)) {
                                best = NULL;
                                active->is_active = 1;
                        }
                }
        }

        if (best && (best == active)) {
                best = NULL;
                active->is_active = 1;
        }

        /* if there is new best aggregator, activate it */
        if (best) {
                pr_debug("best Agg=%d; P=%d; a k=%d; p k=%d; Ind=%d; Act=%d\n",
                         best->aggregator_identifier, best->num_of_ports,
                         best->actor_oper_aggregator_key,
                         best->partner_oper_aggregator_key,
                         best->is_individual, best->is_active);
                pr_debug("best ports %p slave %p %s\n",
                         best->lag_ports, best->slave,
                         best->slave ? best->slave->dev->name : "NULL");

                bond_for_each_slave_rcu(bond, slave, iter) {
                        agg = &(SLAVE_AD_INFO(slave).aggregator);

                        pr_debug("Agg=%d; P=%d; a k=%d; p k=%d; Ind=%d; Act=%d\n",
                                 agg->aggregator_identifier, agg->num_of_ports,
                                 agg->actor_oper_aggregator_key,
                                 agg->partner_oper_aggregator_key,
                                 agg->is_individual, agg->is_active);
                }

                /* check if any partner replys */
                if (best->is_individual) {
                        pr_warn("%s: Warning: No 802.3ad response from the link partner for any adapters in the bond\n",
                                best->slave ?
                                best->slave->bond->dev->name : "NULL");
                }

                best->is_active = 1;
                pr_debug("LAG %d chosen as the active LAG\n",
                         best->aggregator_identifier);
                pr_debug("Agg=%d; P=%d; a k=%d; p k=%d; Ind=%d; Act=%d\n",
                         best->aggregator_identifier, best->num_of_ports,
                         best->actor_oper_aggregator_key,
                         best->partner_oper_aggregator_key,
                         best->is_individual, best->is_active);

                /* disable the ports that were related to the former
                 * active_aggregator
                 */
                if (active) {
                        for (port = active->lag_ports; port;
                             port = port->next_port_in_aggregator) {
                                __disable_port(port);
                        }
                }
        }

        /* if the selected aggregator is of join individuals
         * (partner_system is NULL), enable their ports
         */
        active = __get_active_agg(origin);

        if (active) {
                if (!__agg_has_partner(active)) {
                        for (port = active->lag_ports; port;
                             port = port->next_port_in_aggregator) {
                                __enable_port(port);
                        }
                }
        }

        rcu_read_unlock();

        bond_3ad_set_carrier(bond);
}

/**
 * ad_clear_agg - clear a given aggregator's parameters
 * @aggregator: the aggregator we're looking at
 */
static void ad_clear_agg(struct aggregator *aggregator)
{
        if (aggregator) {
                aggregator->is_individual = false;
                aggregator->actor_admin_aggregator_key = 0;
                aggregator->actor_oper_aggregator_key = 0;
                aggregator->partner_system = null_mac_addr;
                aggregator->partner_system_priority = 0;
                aggregator->partner_oper_aggregator_key = 0;
                aggregator->receive_state = 0;
                aggregator->transmit_state = 0;
                aggregator->lag_ports = NULL;
                aggregator->is_active = 0;
                aggregator->num_of_ports = 0;
                pr_debug("LAG %d was cleared\n",
                         aggregator->aggregator_identifier);
        }
}

/**
 * ad_initialize_agg - initialize a given aggregator's parameters
 * @aggregator: the aggregator we're looking at
 */
static void ad_initialize_agg(struct aggregator *aggregator)
{
        if (aggregator) {
                ad_clear_agg(aggregator);

                aggregator->aggregator_mac_address = null_mac_addr;
                aggregator->aggregator_identifier = 0;
                aggregator->slave = NULL;
        }
}

/**
 * ad_initialize_port - initialize a given port's parameters
 * @aggregator: the aggregator we're looking at
 * @lacp_fast: boolean. whether fast periodic should be used
 */
static void ad_initialize_port(struct port *port, int lacp_fast)
{
        static const struct port_params tmpl = {
                .system_priority = 0xffff,
                .key             = 1,
                .port_number     = 1,
                .port_priority   = 0xff,
                .port_state      = 1,
        };
        static const struct lacpdu lacpdu = {
                .subtype                = 0x01,
                .version_number = 0x01,
                .tlv_type_actor_info = 0x01,
                .actor_information_length = 0x14,
                .tlv_type_partner_info = 0x02,
                .partner_information_length = 0x14,
                .tlv_type_collector_info = 0x03,
                .collector_information_length = 0x10,
                .collector_max_delay = htons(AD_COLLECTOR_MAX_DELAY),
        };

        if (port) {
                port->actor_port_number = 1;
                port->actor_port_priority = 0xff;
                port->actor_system = null_mac_addr;
                port->actor_system_priority = 0xffff;
                port->actor_port_aggregator_identifier = 0;
                port->ntt = false;
                port->actor_admin_port_key = 1;
                port->actor_oper_port_key  = 1;
                port->actor_admin_port_state = AD_STATE_AGGREGATION |
                                               AD_STATE_LACP_ACTIVITY;
                port->actor_oper_port_state  = AD_STATE_AGGREGATION |
                                               AD_STATE_LACP_ACTIVITY;

                if (lacp_fast)
                        port->actor_oper_port_state |= AD_STATE_LACP_TIMEOUT;

                memcpy(&port->partner_admin, &tmpl, sizeof(tmpl));
                memcpy(&port->partner_oper, &tmpl, sizeof(tmpl));

                port->is_enabled = true;
                /* private parameters */
                port->sm_vars = 0x3;
                port->sm_rx_state = 0;
                port->sm_rx_timer_counter = 0;
                port->sm_periodic_state = 0;
                port->sm_periodic_timer_counter = 0;
                port->sm_mux_state = 0;
                port->sm_mux_timer_counter = 0;
                port->sm_tx_state = 0;
                port->sm_tx_timer_counter = 0;
                port->slave = NULL;
                port->aggregator = NULL;
                port->next_port_in_aggregator = NULL;
                port->transaction_id = 0;

                memcpy(&port->lacpdu, &lacpdu, sizeof(lacpdu));
        }
}

/**
 * ad_enable_collecting_distributing - enable a port's transmit/receive
 * @port: the port we're looking at
 *
 * Enable @port if it's in an active aggregator
 */
static void ad_enable_collecting_distributing(struct port *port)
{
        if (port->aggregator->is_active) {
                pr_debug("Enabling port %d(LAG %d)\n",
                         port->actor_port_number,
                         port->aggregator->aggregator_identifier);
                __enable_port(port);
        }
}

/**
 * ad_disable_collecting_distributing - disable a port's transmit/receive
 * @port: the port we're looking at
 */
static void ad_disable_collecting_distributing(struct port *port)
{
        if (port->aggregator &&
            !MAC_ADDRESS_EQUAL(&(port->aggregator->partner_system),
                               &(null_mac_addr))) {
                pr_debug("Disabling port %d(LAG %d)\n",
                         port->actor_port_number,
                         port->aggregator->aggregator_identifier);
                __disable_port(port);
        }
}

/**
 * ad_marker_info_received - handle receive of a Marker information frame
 * @marker_info: Marker info received
 * @port: the port we're looking at
 */
static void ad_marker_info_received(struct bond_marker *marker_info,
        struct port *port)
{
        struct bond_marker marker;

        /* copy the received marker data to the response marker */
        memcpy(&marker, marker_info, sizeof(struct bond_marker));
        /* change the marker subtype to marker response */
        marker.tlv_type = AD_MARKER_RESPONSE_SUBTYPE;

        /* send the marker response */
        if (ad_marker_send(port, &marker) >= 0) {
                pr_debug("Sent Marker Response on port %d\n",
                         port->actor_port_number);
        }
}

/**
 * ad_marker_response_received - handle receive of a marker response frame
 * @marker: marker PDU received
 * @port: the port we're looking at
 *
 * This function does nothing since we decided not to implement send and handle
 * response for marker PDU's, in this stage, but only to respond to marker
 * information.
 */
static void ad_marker_response_received(struct bond_marker *marker,
                                        struct port *port)
{
        marker = NULL;
        port = NULL;
        /* DO NOTHING, SINCE WE DECIDED NOT TO IMPLEMENT THIS FEATURE FOR NOW */
}

/* ========= AD exported functions to the main bonding code ========= */

/* Check aggregators status in team every T seconds */
#define AD_AGGREGATOR_SELECTION_TIMER  8

/**
 * bond_3ad_initiate_agg_selection - initate aggregator selection
 * @bond: bonding struct
 *
 * Set the aggregation selection timer, to initiate an agg selection in
 * the very near future.  Called during first initialization, and during
 * any down to up transitions of the bond.
 */
void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout)
{
        BOND_AD_INFO(bond).agg_select_timer = timeout;
}

static u16 aggregator_identifier;

/**
 * bond_3ad_initialize - initialize a bond's 802.3ad parameters and structures
 * @bond: bonding struct to work on
 * @tick_resolution: tick duration (millisecond resolution)
 *
 * Can be called only after the mac address of the bond is set.
 */
void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution)
{
        /* check that the bond is not initialized yet */
        if (!MAC_ADDRESS_EQUAL(&(BOND_AD_INFO(bond).system.sys_mac_addr),
                                bond->dev->dev_addr)) {

                aggregator_identifier = 0;

                BOND_AD_INFO(bond).system.sys_priority = 0xFFFF;
                BOND_AD_INFO(bond).system.sys_mac_addr = *((struct mac_addr *)bond->dev->dev_addr);

                /* initialize how many times this module is called in one
                 * second (should be about every 100ms)
                 */
                ad_ticks_per_sec = tick_resolution;

                bond_3ad_initiate_agg_selection(bond,
                                                AD_AGGREGATOR_SELECTION_TIMER *
                                                ad_ticks_per_sec);
        }
}

/**
 * bond_3ad_bind_slave - initialize a slave's port
 * @slave: slave struct to work on
 *
 * Returns:   0 on success
 *          < 0 on error
 */
void bond_3ad_bind_slave(struct slave *slave)
{
        struct bonding *bond = bond_get_bond_by_slave(slave);
        struct port *port;
        struct aggregator *aggregator;

        /* check that the slave has not been initialized yet. */
        if (SLAVE_AD_INFO(slave).port.slave != slave) {

                /* port initialization */
                port = &(SLAVE_AD_INFO(slave).port);

                ad_initialize_port(port, bond->params.lacp_fast);

                __initialize_port_locks(slave);
                port->slave = slave;
                port->actor_port_number = SLAVE_AD_INFO(slave).id;
                /* key is determined according to the link speed, duplex and user key(which
                 * is yet not supported)
                 */
                port->actor_admin_port_key = 0;
                port->actor_admin_port_key |= __get_duplex(port);
                port->actor_admin_port_key |= (__get_link_speed(port) << 1);
                port->actor_oper_port_key = port->actor_admin_port_key;
                /* if the port is not full duplex, then the port should be not
                 * lacp Enabled
                 */
                if (!(port->actor_oper_port_key & AD_DUPLEX_KEY_BITS))
                        port->sm_vars &= ~AD_PORT_LACP_ENABLED;
                /* actor system is the bond's system */
                port->actor_system = BOND_AD_INFO(bond).system.sys_mac_addr;
                /* tx timer(to verify that no more than MAX_TX_IN_SECOND
                 * lacpdu's are sent in one second)
                 */
                port->sm_tx_timer_counter = ad_ticks_per_sec/AD_MAX_TX_IN_SECOND;
                port->aggregator = NULL;
                port->next_port_in_aggregator = NULL;

                __disable_port(port);

                /* aggregator initialization */
                aggregator = &(SLAVE_AD_INFO(slave).aggregator);

                ad_initialize_agg(aggregator);

                aggregator->aggregator_mac_address = *((struct mac_addr *)bond->dev->dev_addr);
                aggregator->aggregator_identifier = (++aggregator_identifier);
                aggregator->slave = slave;
                aggregator->is_active = 0;
                aggregator->num_of_ports = 0;
        }
}

/**
 * bond_3ad_unbind_slave - deinitialize a slave's port
 * @slave: slave struct to work on
 *
 * Search for the aggregator that is related to this port, remove the
 * aggregator and assign another aggregator for other port related to it
 * (if any), and remove the port.
 */
void bond_3ad_unbind_slave(struct slave *slave)
{
        struct port *port, *prev_port, *temp_port;
        struct aggregator *aggregator, *new_aggregator, *temp_aggregator;
        int select_new_active_agg = 0;
        struct bonding *bond = slave->bond;
        struct slave *slave_iter;
        struct list_head *iter;

        aggregator = &(SLAVE_AD_INFO(slave).aggregator);
        port = &(SLAVE_AD_INFO(slave).port);

        /* if slave is null, the whole port is not initialized */
        if (!port->slave) {
                pr_warn("Warning: %s: Trying to unbind an uninitialized port on %s\n",
                        slave->bond->dev->name, slave->dev->name);
                return;
        }

        pr_debug("Unbinding Link Aggregation Group %d\n",
                 aggregator->aggregator_identifier);

        /* Tell the partner that this port is not suitable for aggregation */
        port->actor_oper_port_state &= ~AD_STATE_AGGREGATION;
        __update_lacpdu_from_port(port);
        ad_lacpdu_send(port);

        /* check if this aggregator is occupied */
        if (aggregator->lag_ports) {
                /* check if there are other ports related to this aggregator
                 * except the port related to this slave(thats ensure us that
                 * there is a reason to search for new aggregator, and that we
                 * will find one
                 */
                if ((aggregator->lag_ports != port) ||
                    (aggregator->lag_ports->next_port_in_aggregator)) {
                        /* find new aggregator for the related port(s) */
                        bond_for_each_slave(bond, slave_iter, iter) {
                                new_aggregator = &(SLAVE_AD_INFO(slave_iter).aggregator);
                                /* if the new aggregator is empty, or it is
                                 * connected to our port only
                                 */
                                if (!new_aggregator->lag_ports ||
                                    ((new_aggregator->lag_ports == port) &&
                                     !new_aggregator->lag_ports->next_port_in_aggregator))
                                        break;
                        }
                        if (!slave_iter)
                                new_aggregator = NULL;

                        /* if new aggregator found, copy the aggregator's
                         * parameters and connect the related lag_ports to the
                         * new aggregator
                         */
                        if ((new_aggregator) && ((!new_aggregator->lag_ports) || ((new_aggregator->lag_ports == port) && !new_aggregator->lag_ports->next_port_in_aggregator))) {
                                pr_debug("Some port(s) related to LAG %d - replaceing with LAG %d\n",
                                         aggregator->aggregator_identifier,
                                         new_aggregator->aggregator_identifier);

                                if ((new_aggregator->lag_ports == port) &&
                                    new_aggregator->is_active) {
                                        pr_info("%s: Removing an active aggregator\n",
                                                aggregator->slave->bond->dev->name);
                                         select_new_active_agg = 1;
                                }

                                new_aggregator->is_individual = aggregator->is_individual;
                                new_aggregator->actor_admin_aggregator_key = aggregator->actor_admin_aggregator_key;
                                new_aggregator->actor_oper_aggregator_key = aggregator->actor_oper_aggregator_key;
                                new_aggregator->partner_system = aggregator->partner_system;
                                new_aggregator->partner_system_priority = aggregator->partner_system_priority;
                                new_aggregator->partner_oper_aggregator_key = aggregator->partner_oper_aggregator_key;
                                new_aggregator->receive_state = aggregator->receive_state;
                                new_aggregator->transmit_state = aggregator->transmit_state;
                                new_aggregator->lag_ports = aggregator->lag_ports;
                                new_aggregator->is_active = aggregator->is_active;
                                new_aggregator->num_of_ports = aggregator->num_of_ports;

                                /* update the information that is written on
                                 * the ports about the aggregator
                                 */
                                for (temp_port = aggregator->lag_ports; temp_port;
                                     temp_port = temp_port->next_port_in_aggregator) {
                                        temp_port->aggregator = new_aggregator;
                                        temp_port->actor_port_aggregator_identifier = new_aggregator->aggregator_identifier;
                                }

                                ad_clear_agg(aggregator);

                                if (select_new_active_agg)
                                        ad_agg_selection_logic(__get_first_agg(port));
                        } else {
                                pr_warn("%s: Warning: unbinding aggregator, and could not find a new aggregator for its ports\n",
                                        slave->bond->dev->name);
                        }
                } else {
                        /* in case that the only port related to this
                         * aggregator is the one we want to remove
                         */
                        select_new_active_agg = aggregator->is_active;
                        ad_clear_agg(aggregator);
                        if (select_new_active_agg) {
                                pr_info("%s: Removing an active aggregator\n",
                                        slave->bond->dev->name);
                                /* select new active aggregator */
                                temp_aggregator = __get_first_agg(port);
                                if (temp_aggregator)
                                        ad_agg_selection_logic(temp_aggregator);
                        }
                }
        }

        pr_debug("Unbinding port %d\n", port->actor_port_number);

        /* find the aggregator that this port is connected to */
        bond_for_each_slave(bond, slave_iter, iter) {
                temp_aggregator = &(SLAVE_AD_INFO(slave_iter).aggregator);
                prev_port = NULL;
                /* search the port in the aggregator's related ports */
                for (temp_port = temp_aggregator->lag_ports; temp_port;
                     prev_port = temp_port,
                     temp_port = temp_port->next_port_in_aggregator) {
                        if (temp_port == port) {
                                /* the aggregator found - detach the port from
                                 * this aggregator
                                 */
                                if (prev_port)
                                        prev_port->next_port_in_aggregator = temp_port->next_port_in_aggregator;
                                else
                                        temp_aggregator->lag_ports = temp_port->next_port_in_aggregator;
                                temp_aggregator->num_of_ports--;
                                if (temp_aggregator->num_of_ports == 0) {
                                        select_new_active_agg = temp_aggregator->is_active;
                                        ad_clear_agg(temp_aggregator);
                                        if (select_new_active_agg) {
                                                pr_info("%s: Removing an active aggregator\n",
                                                        slave->bond->dev->name);
                                                /* select new active aggregator */
                                                ad_agg_selection_logic(__get_first_agg(port));
                                        }
                                }
                                break;
                        }
                }
        }
        port->slave = NULL;
}

/**
 * bond_3ad_state_machine_handler - handle state machines timeout
 * @bond: bonding struct to work on
 *
 * The state machine handling concept in this module is to check every tick
 * which state machine should operate any function. The execution order is
 * round robin, so when we have an interaction between state machines, the
 * reply of one to each other might be delayed until next tick.
 *
 * This function also complete the initialization when the agg_select_timer
 * times out, and it selects an aggregator for the ports that are yet not
 * related to any aggregator, and selects the active aggregator for a bond.
 */
void bond_3ad_state_machine_handler(struct work_struct *work)
{
        struct bonding *bond = container_of(work, struct bonding,
                                            ad_work.work);
        struct aggregator *aggregator;
        struct list_head *iter;
        struct slave *slave;
        struct port *port;

        read_lock(&bond->lock);
        rcu_read_lock();

        /* check if there are any slaves */
        if (!bond_has_slaves(bond))
                goto re_arm;

        /* check if agg_select_timer timer after initialize is timed out */
        if (BOND_AD_INFO(bond).agg_select_timer &&
            !(--BOND_AD_INFO(bond).agg_select_timer)) {
                slave = bond_first_slave_rcu(bond);
                port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL;

                /* select the active aggregator for the bond */
                if (port) {
                        if (!port->slave) {
                                pr_warn("%s: Warning: bond's first port is uninitialized\n",
                                        bond->dev->name);
                                goto re_arm;
                        }

                        aggregator = __get_first_agg(port);
                        ad_agg_selection_logic(aggregator);
                }
                bond_3ad_set_carrier(bond);
        }

        /* for each port run the state machines */
        bond_for_each_slave_rcu(bond, slave, iter) {
                port = &(SLAVE_AD_INFO(slave).port);
                if (!port->slave) {
                        pr_warn("%s: Warning: Found an uninitialized port\n",
                                bond->dev->name);
                        goto re_arm;
                }

                /* Lock around state machines to protect data accessed
                 * by all (e.g., port->sm_vars).  ad_rx_machine may run
                 * concurrently due to incoming LACPDU.
                 */
                __get_state_machine_lock(port);

                ad_rx_machine(NULL, port);
                ad_periodic_machine(port);
                ad_port_selection_logic(port);
                ad_mux_machine(port);
                ad_tx_machine(port);

                /* turn off the BEGIN bit, since we already handled it */
                if (port->sm_vars & AD_PORT_BEGIN)
                        port->sm_vars &= ~AD_PORT_BEGIN;

                __release_state_machine_lock(port);
        }

re_arm:
        rcu_read_unlock();
        read_unlock(&bond->lock);
        queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks);
}

/**
 * bond_3ad_rx_indication - handle a received frame
 * @lacpdu: received lacpdu
 * @slave: slave struct to work on
 * @length: length of the data received
 *
 * It is assumed that frames that were sent on this NIC don't returned as new
 * received frames (loopback). Since only the payload is given to this
 * function, it check for loopback.
 */
static int bond_3ad_rx_indication(struct lacpdu *lacpdu, struct slave *slave,
                                  u16 length)
{
        struct port *port;
        int ret = RX_HANDLER_ANOTHER;

        if (length >= sizeof(struct lacpdu)) {

                port = &(SLAVE_AD_INFO(slave).port);

                if (!port->slave) {
                        pr_warn("%s: Warning: port of slave %s is uninitialized\n",
                                slave->dev->name, slave->bond->dev->name);
                        return ret;
                }

                switch (lacpdu->subtype) {
                case AD_TYPE_LACPDU:
                        ret = RX_HANDLER_CONSUMED;
                        pr_debug("Received LACPDU on port %d\n",
                                 port->actor_port_number);
                        /* Protect against concurrent state machines */
                        __get_state_machine_lock(port);
                        ad_rx_machine(lacpdu, port);
                        __release_state_machine_lock(port);
                        break;

                case AD_TYPE_MARKER:
                        ret = RX_HANDLER_CONSUMED;
                        /* No need to convert fields to Little Endian since we
                         * don't use the marker's fields.
                         */

                        switch (((struct bond_marker *)lacpdu)->tlv_type) {
                        case AD_MARKER_INFORMATION_SUBTYPE:
                                pr_debug("Received Marker Information on port %d\n",
                                         port->actor_port_number);
                                ad_marker_info_received((struct bond_marker *)lacpdu, port);
                                break;

                        case AD_MARKER_RESPONSE_SUBTYPE:
                                pr_debug("Received Marker Response on port %d\n",
                                         port->actor_port_number);
                                ad_marker_response_received((struct bond_marker *)lacpdu, port);
                                break;

                        default:
                                pr_debug("Received an unknown Marker subtype on slot %d\n",
                                         port->actor_port_number);
                        }
                }
        }
        return ret;
}

/**
 * bond_3ad_adapter_speed_changed - handle a slave's speed change indication
 * @slave: slave struct to work on
 *
 * Handle reselection of aggregator (if needed) for this port.
 */
void bond_3ad_adapter_speed_changed(struct slave *slave)
{
        struct port *port;

        port = &(SLAVE_AD_INFO(slave).port);

        /* if slave is null, the whole port is not initialized */
        if (!port->slave) {
                pr_warn("Warning: %s: speed changed for uninitialized port on %s\n",
                        slave->bond->dev->name, slave->dev->name);
                return;
        }

        __get_state_machine_lock(port);

        port->actor_admin_port_key &= ~AD_SPEED_KEY_BITS;
        port->actor_oper_port_key = port->actor_admin_port_key |=
                (__get_link_speed(port) << 1);
        pr_debug("Port %d changed speed\n", port->actor_port_number);
        /* there is no need to reselect a new aggregator, just signal the
         * state machines to reinitialize
         */
        port->sm_vars |= AD_PORT_BEGIN;

        __release_state_machine_lock(port);
}

/**
 * bond_3ad_adapter_duplex_changed - handle a slave's duplex change indication
 * @slave: slave struct to work on
 *
 * Handle reselection of aggregator (if needed) for this port.
 */
void bond_3ad_adapter_duplex_changed(struct slave *slave)
{
        struct port *port;

        port = &(SLAVE_AD_INFO(slave).port);

        /* if slave is null, the whole port is not initialized */
        if (!port->slave) {
                pr_warn("%s: Warning: duplex changed for uninitialized port on %s\n",
                        slave->bond->dev->name, slave->dev->name);
                return;
        }

        __get_state_machine_lock(port);

        port->actor_admin_port_key &= ~AD_DUPLEX_KEY_BITS;
        port->actor_oper_port_key = port->actor_admin_port_key |=
                __get_duplex(port);
        pr_debug("Port %d changed duplex\n", port->actor_port_number);
        /* there is no need to reselect a new aggregator, just signal the
         * state machines to reinitialize
         */
        port->sm_vars |= AD_PORT_BEGIN;

        __release_state_machine_lock(port);
}

/**
 * bond_3ad_handle_link_change - handle a slave's link status change indication
 * @slave: slave struct to work on
 * @status: whether the link is now up or down
 *
 * Handle reselection of aggregator (if needed) for this port.
 */
void bond_3ad_handle_link_change(struct slave *slave, char link)
{
        struct port *port;

        port = &(SLAVE_AD_INFO(slave).port);

        /* if slave is null, the whole port is not initialized */
        if (!port->slave) {
                pr_warn("Warning: %s: link status changed for uninitialized port on %s\n",
                        slave->bond->dev->name, slave->dev->name);
                return;
        }

        __get_state_machine_lock(port);
        /* on link down we are zeroing duplex and speed since
         * some of the adaptors(ce1000.lan) report full duplex/speed
         * instead of N/A(duplex) / 0(speed).
         *
         * on link up we are forcing recheck on the duplex and speed since
         * some of he adaptors(ce1000.lan) report.
         */
        if (link == BOND_LINK_UP) {
                port->is_enabled = true;
                port->actor_admin_port_key &= ~AD_DUPLEX_KEY_BITS;
                port->actor_oper_port_key = port->actor_admin_port_key |=
                        __get_duplex(port);
                port->actor_admin_port_key &= ~AD_SPEED_KEY_BITS;
                port->actor_oper_port_key = port->actor_admin_port_key |=
                        (__get_link_speed(port) << 1);
        } else {
                /* link has failed */
                port->is_enabled = false;
                port->actor_admin_port_key &= ~AD_DUPLEX_KEY_BITS;
                port->actor_oper_port_key = (port->actor_admin_port_key &=
                                             ~AD_SPEED_KEY_BITS);
        }
        pr_debug("Port %d changed link status to %s",
                port->actor_port_number,
                (link == BOND_LINK_UP) ? "UP" : "DOWN");
        /* there is no need to reselect a new aggregator, just signal the
         * state machines to reinitialize
         */
        port->sm_vars |= AD_PORT_BEGIN;

        __release_state_machine_lock(port);
}

/**
 * bond_3ad_set_carrier - set link state for bonding master
 * @bond - bonding structure
 *
 * if we have an active aggregator, we're up, if not, we're down.
 * Presumes that we cannot have an active aggregator if there are
 * no slaves with link up.
 *
 * This behavior complies with IEEE 802.3 section 43.3.9.
 *
 * Called by bond_set_carrier(). Return zero if carrier state does not
 * change, nonzero if it does.
 */
int bond_3ad_set_carrier(struct bonding *bond)
{
        struct aggregator *active;
        struct slave *first_slave;

        rcu_read_lock();
        first_slave = bond_first_slave_rcu(bond);
        rcu_read_unlock();
        if (!first_slave)
                return 0;
        active = __get_active_agg(&(SLAVE_AD_INFO(first_slave).aggregator));
        if (active) {
                /* are enough slaves available to consider link up? */
                if (active->num_of_ports < bond->params.min_links) {
                        if (netif_carrier_ok(bond->dev)) {
                                netif_carrier_off(bond->dev);
                                return 1;
                        }
                } else if (!netif_carrier_ok(bond->dev)) {
                        netif_carrier_on(bond->dev);
                        return 1;
                }
                return 0;
        }

        if (netif_carrier_ok(bond->dev)) {
                netif_carrier_off(bond->dev);
                return 1;
        }
        return 0;
}

/**
 * __bond_3ad_get_active_agg_info - get information of the active aggregator
 * @bond: bonding struct to work on
 * @ad_info: ad_info struct to fill with the bond's info
 *
 * Returns:   0 on success
 *          < 0 on error
 */
int __bond_3ad_get_active_agg_info(struct bonding *bond,
                                   struct ad_info *ad_info)
{
        struct aggregator *aggregator = NULL;
        struct list_head *iter;
        struct slave *slave;
        struct port *port;

        bond_for_each_slave_rcu(bond, slave, iter) {
                port = &(SLAVE_AD_INFO(slave).port);
                if (port->aggregator && port->aggregator->is_active) {
                        aggregator = port->aggregator;
                        break;
                }
        }

        if (aggregator) {
                ad_info->aggregator_id = aggregator->aggregator_identifier;
                ad_info->ports = aggregator->num_of_ports;
                ad_info->actor_key = aggregator->actor_oper_aggregator_key;
                ad_info->partner_key = aggregator->partner_oper_aggregator_key;
                memcpy(ad_info->partner_system,
                       aggregator->partner_system.mac_addr_value, ETH_ALEN);
                return 0;
        }

        return -1;
}

/* Wrapper used to hold bond->lock so no slave manipulation can occur */
int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info)
{
        int ret;

        rcu_read_lock();
        ret = __bond_3ad_get_active_agg_info(bond, ad_info);
        rcu_read_unlock();

        return ret;
}

int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
{
        struct bonding *bond = netdev_priv(dev);
        struct slave *slave, *first_ok_slave;
        struct aggregator *agg;
        struct ad_info ad_info;
        struct list_head *iter;
        int slaves_in_agg;
        int slave_agg_no;
        int agg_id;

        if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
                pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n",
                         dev->name);
                goto err_free;
        }

        slaves_in_agg = ad_info.ports;
        agg_id = ad_info.aggregator_id;

        if (slaves_in_agg == 0) {
                pr_debug("%s: Error: active aggregator is empty\n", dev->name);
                goto err_free;
        }

        slave_agg_no = bond_xmit_hash(bond, skb, slaves_in_agg);
        first_ok_slave = NULL;

        bond_for_each_slave_rcu(bond, slave, iter) {
                agg = SLAVE_AD_INFO(slave).port.aggregator;
                if (!agg || agg->aggregator_identifier != agg_id)
                        continue;

                if (slave_agg_no >= 0) {
                        if (!first_ok_slave && SLAVE_IS_OK(slave))
                                first_ok_slave = slave;
                        slave_agg_no--;
                        continue;
                }

                if (SLAVE_IS_OK(slave)) {
                        bond_dev_queue_xmit(bond, skb, slave->dev);
                        goto out;
                }
        }

        if (slave_agg_no >= 0) {
                pr_err("%s: Error: Couldn't find a slave to tx on for aggregator ID %d\n",
                       dev->name, agg_id);
                goto err_free;
        }

        /* we couldn't find any suitable slave after the agg_no, so use the
         * first suitable found, if found.
         */
        if (first_ok_slave)
                bond_dev_queue_xmit(bond, skb, first_ok_slave->dev);
        else
                goto err_free;

out:
        return NETDEV_TX_OK;
err_free:
        /* no suitable interface, frame not sent */
        kfree_skb(skb);
        goto out;
}

int bond_3ad_lacpdu_recv(const struct sk_buff *skb, struct bonding *bond,
                         struct slave *slave)
{
        int ret = RX_HANDLER_ANOTHER;
        struct lacpdu *lacpdu, _lacpdu;

        if (skb->protocol != PKT_TYPE_LACPDU)
                return ret;

        lacpdu = skb_header_pointer(skb, 0, sizeof(_lacpdu), &_lacpdu);
        if (!lacpdu)
                return ret;

        read_lock(&bond->lock);
        ret = bond_3ad_rx_indication(lacpdu, slave, skb->len);
        read_unlock(&bond->lock);
        return ret;
}

/**
 * bond_3ad_update_lacp_rate - change the lacp rate
 * @bond - bonding struct
 *
 * When modify lacp_rate parameter via sysfs,
 * update actor_oper_port_state of each port.
 *
 * Hold slave->state_machine_lock,
 * so we can modify port->actor_oper_port_state,
 * no matter bond is up or down.
 */
void bond_3ad_update_lacp_rate(struct bonding *bond)
{
        struct port *port = NULL;
        struct list_head *iter;
        struct slave *slave;
        int lacp_fast;

        lacp_fast = bond->params.lacp_fast;
        bond_for_each_slave(bond, slave, iter) {
                port = &(SLAVE_AD_INFO(slave).port);
                __get_state_machine_lock(port);
                if (lacp_fast)
                        port->actor_oper_port_state |= AD_STATE_LACP_TIMEOUT;
                else
                        port->actor_oper_port_state &= ~AD_STATE_LACP_TIMEOUT;
                __release_state_machine_lock(port);
        }
}