5013 add support for multiple mac addresses per client

[unleashed.git] / usr / src / uts / common / io / mac / mac_client.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2013, Joyent, Inc.  All rights reserved.
 */

/*
 * - General Introduction:
 *
 * This file contains the implementation of the MAC client kernel
 * API and related code. The MAC client API allows a kernel module
 * to gain access to a MAC instance (physical NIC, link aggregation, etc).
 * It allows a MAC client to associate itself with a MAC address,
 * VLANs, callback functions for data traffic and for promiscuous mode.
 * The MAC client API is also used to specify the properties associated
 * with a MAC client, such as bandwidth limits, priority, CPUS, etc.
 * These properties are further used to determine the hardware resources
 * to allocate to the various MAC clients.
 *
 * - Primary MAC clients:
 *
 * The MAC client API refers to "primary MAC clients". A primary MAC
 * client is a client which "owns" the primary MAC address of
 * the underlying MAC instance. The primary MAC address is called out
 * since it is associated with specific semantics: the primary MAC
 * address is the MAC address which is assigned to the IP interface
 * when it is plumbed, and the primary MAC address is assigned
 * to VLAN data-links. The primary address of a MAC instance can
 * also change dynamically from under the MAC client, for example
 * as a result of a change of state of a link aggregation. In that
 * case the MAC layer automatically updates all data-structures which
 * refer to the current value of the primary MAC address. Typical
 * primary MAC clients are dls, aggr, and xnb. A typical non-primary
 * MAC client is the vnic driver.
 *
 * - Virtual Switching:
 *
 * The MAC layer implements a virtual switch between the MAC clients
 * (primary and non-primary) defined on top of the same underlying
 * NIC (physical, link aggregation, etc). The virtual switch is
 * VLAN-aware, i.e. it allows multiple MAC clients to be member
 * of one or more VLANs, and the virtual switch will distribute
 * multicast tagged packets only to the member of the corresponding
 * VLANs.
 *
 * - Upper vs Lower MAC:
 *
 * Creating a VNIC on top of a MAC instance effectively causes
 * two MAC instances to be layered on top of each other, one for
 * the VNIC(s), one for the underlying MAC instance (physical NIC,
 * link aggregation, etc). In the code below we refer to the
 * underlying NIC as the "lower MAC", and we refer to VNICs as
 * the "upper MAC".
 *
 * - Pass-through for VNICs:
 *
 * When VNICs are created on top of an underlying MAC, this causes
 * a layering of two MAC instances. Since the lower MAC already
 * does the switching and demultiplexing to its MAC clients, the
 * upper MAC would simply have to pass packets to the layer below
 * or above it, which would introduce overhead. In order to avoid
 * this overhead, the MAC layer implements a pass-through mechanism
 * for VNICs. When a VNIC opens the lower MAC instance, it saves
 * the MAC client handle it optains from the MAC layer. When a MAC
 * client opens a VNIC (upper MAC), the MAC layer detects that
 * the MAC being opened is a VNIC, and gets the MAC client handle
 * that the VNIC driver obtained from the lower MAC. This exchange
 * is done through a private capability between the MAC layer
 * and the VNIC driver. The upper MAC then returns that handle
 * directly to its MAC client. Any operation done by the upper
 * MAC client is now done on the lower MAC client handle, which
 * allows the VNIC driver to be completely bypassed for the
 * performance sensitive data-path.
 *
 * - Secondary MACs for VNICs:
 *
 * VNICs support multiple upper mac clients to enable support for
 * multiple MAC addresses on the VNIC. When the VNIC is created the
 * initial mac client is the primary upper mac. Any additional mac
 * clients are secondary macs. These are kept in sync with the primary
 * (for things such as the rx function and resource control settings)
 * using the same private capability interface between the MAC layer
 * and the VNIC layer.
 *
 */

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/id_space.h>
#include <sys/esunddi.h>
#include <sys/stat.h>
#include <sys/mkdev.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/strsubr.h>
#include <sys/dlpi.h>
#include <sys/modhash.h>
#include <sys/mac_impl.h>
#include <sys/mac_client_impl.h>
#include <sys/mac_soft_ring.h>
#include <sys/mac_stat.h>
#include <sys/dls.h>
#include <sys/dld.h>
#include <sys/modctl.h>
#include <sys/fs/dv_node.h>
#include <sys/thread.h>
#include <sys/proc.h>
#include <sys/callb.h>
#include <sys/cpuvar.h>
#include <sys/atomic.h>
#include <sys/sdt.h>
#include <sys/mac_flow.h>
#include <sys/ddi_intr_impl.h>
#include <sys/disp.h>
#include <sys/sdt.h>
#include <sys/vnic.h>
#include <sys/vnic_impl.h>
#include <sys/vlan.h>
#include <inet/ip.h>
#include <inet/ip6.h>
#include <sys/exacct.h>
#include <sys/exacct_impl.h>
#include <inet/nd.h>
#include <sys/ethernet.h>

kmem_cache_t    *mac_client_impl_cache;
kmem_cache_t    *mac_promisc_impl_cache;

static boolean_t mac_client_single_rcvr(mac_client_impl_t *);
static flow_entry_t *mac_client_swap_mciflent(mac_client_impl_t *);
static flow_entry_t *mac_client_get_flow(mac_client_impl_t *,
    mac_unicast_impl_t *);
static void mac_client_remove_flow_from_list(mac_client_impl_t *,
    flow_entry_t *);
static void mac_client_add_to_flow_list(mac_client_impl_t *, flow_entry_t *);
static void mac_rename_flow_names(mac_client_impl_t *, const char *);
static void mac_virtual_link_update(mac_impl_t *);
static int mac_client_datapath_setup(mac_client_impl_t *, uint16_t,
    uint8_t *, mac_resource_props_t *, boolean_t, mac_unicast_impl_t *);
static void mac_client_datapath_teardown(mac_client_handle_t,
    mac_unicast_impl_t *, flow_entry_t *);
static int mac_resource_ctl_set(mac_client_handle_t, mac_resource_props_t *);

/* ARGSUSED */
static int
i_mac_client_impl_ctor(void *buf, void *arg, int kmflag)
{
        int     i;
        mac_client_impl_t       *mcip = buf;

        bzero(buf, MAC_CLIENT_IMPL_SIZE);
        mutex_init(&mcip->mci_tx_cb_lock, NULL, MUTEX_DRIVER, NULL);
        mcip->mci_tx_notify_cb_info.mcbi_lockp = &mcip->mci_tx_cb_lock;

        ASSERT(mac_tx_percpu_cnt >= 0);
        for (i = 0; i <= mac_tx_percpu_cnt; i++) {
                mutex_init(&mcip->mci_tx_pcpu[i].pcpu_tx_lock, NULL,
                    MUTEX_DRIVER, NULL);
        }
        cv_init(&mcip->mci_tx_cv, NULL, CV_DRIVER, NULL);

        return (0);
}

/* ARGSUSED */
static void
i_mac_client_impl_dtor(void *buf, void *arg)
{
        int     i;
        mac_client_impl_t *mcip = buf;

        ASSERT(mcip->mci_promisc_list == NULL);
        ASSERT(mcip->mci_unicast_list == NULL);
        ASSERT(mcip->mci_state_flags == 0);
        ASSERT(mcip->mci_tx_flag == 0);

        mutex_destroy(&mcip->mci_tx_cb_lock);

        ASSERT(mac_tx_percpu_cnt >= 0);
        for (i = 0; i <= mac_tx_percpu_cnt; i++) {
                ASSERT(mcip->mci_tx_pcpu[i].pcpu_tx_refcnt == 0);
                mutex_destroy(&mcip->mci_tx_pcpu[i].pcpu_tx_lock);
        }
        cv_destroy(&mcip->mci_tx_cv);
}

/* ARGSUSED */
static int
i_mac_promisc_impl_ctor(void *buf, void *arg, int kmflag)
{
        mac_promisc_impl_t      *mpip = buf;

        bzero(buf, sizeof (mac_promisc_impl_t));
        mpip->mpi_mci_link.mcb_objp = buf;
        mpip->mpi_mci_link.mcb_objsize = sizeof (mac_promisc_impl_t);
        mpip->mpi_mi_link.mcb_objp = buf;
        mpip->mpi_mi_link.mcb_objsize = sizeof (mac_promisc_impl_t);
        return (0);
}

/* ARGSUSED */
static void
i_mac_promisc_impl_dtor(void *buf, void *arg)
{
        mac_promisc_impl_t      *mpip = buf;

        ASSERT(mpip->mpi_mci_link.mcb_objp != NULL);
        ASSERT(mpip->mpi_mci_link.mcb_objsize == sizeof (mac_promisc_impl_t));
        ASSERT(mpip->mpi_mi_link.mcb_objp == mpip->mpi_mci_link.mcb_objp);
        ASSERT(mpip->mpi_mi_link.mcb_objsize == sizeof (mac_promisc_impl_t));

        mpip->mpi_mci_link.mcb_objp = NULL;
        mpip->mpi_mci_link.mcb_objsize = 0;
        mpip->mpi_mi_link.mcb_objp = NULL;
        mpip->mpi_mi_link.mcb_objsize = 0;

        ASSERT(mpip->mpi_mci_link.mcb_flags == 0);
        mpip->mpi_mci_link.mcb_objsize = 0;
}

void
mac_client_init(void)
{
        ASSERT(mac_tx_percpu_cnt >= 0);

        mac_client_impl_cache = kmem_cache_create("mac_client_impl_cache",
            MAC_CLIENT_IMPL_SIZE, 0, i_mac_client_impl_ctor,
            i_mac_client_impl_dtor, NULL, NULL, NULL, 0);
        ASSERT(mac_client_impl_cache != NULL);

        mac_promisc_impl_cache = kmem_cache_create("mac_promisc_impl_cache",
            sizeof (mac_promisc_impl_t), 0, i_mac_promisc_impl_ctor,
            i_mac_promisc_impl_dtor, NULL, NULL, NULL, 0);
        ASSERT(mac_promisc_impl_cache != NULL);
}

void
mac_client_fini(void)
{
        kmem_cache_destroy(mac_client_impl_cache);
        kmem_cache_destroy(mac_promisc_impl_cache);
}

/*
 * Return the lower MAC client handle from the VNIC driver for the
 * specified VNIC MAC instance.
 */
mac_client_impl_t *
mac_vnic_lower(mac_impl_t *mip)
{
        mac_capab_vnic_t cap;
        mac_client_impl_t *mcip;

        VERIFY(i_mac_capab_get((mac_handle_t)mip, MAC_CAPAB_VNIC, &cap));
        mcip = cap.mcv_mac_client_handle(cap.mcv_arg);

        return (mcip);
}

/*
 * Update the secondary macs
 */
void
mac_vnic_secondary_update(mac_impl_t *mip)
{
        mac_capab_vnic_t cap;

        VERIFY(i_mac_capab_get((mac_handle_t)mip, MAC_CAPAB_VNIC, &cap));
        cap.mcv_mac_secondary_update(cap.mcv_arg);
}

/*
 * Return the MAC client handle of the primary MAC client for the
 * specified MAC instance, or NULL otherwise.
 */
mac_client_impl_t *
mac_primary_client_handle(mac_impl_t *mip)
{
        mac_client_impl_t *mcip;

        if (mip->mi_state_flags & MIS_IS_VNIC)
                return (mac_vnic_lower(mip));

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        for (mcip = mip->mi_clients_list; mcip != NULL;
            mcip = mcip->mci_client_next) {
                if (MCIP_DATAPATH_SETUP(mcip) && mac_is_primary_client(mcip))
                        return (mcip);
        }
        return (NULL);
}

/*
 * Open a MAC specified by its MAC name.
 */
int
mac_open(const char *macname, mac_handle_t *mhp)
{
        mac_impl_t      *mip;
        int             err;

        /*
         * Look up its entry in the global hash table.
         */
        if ((err = mac_hold(macname, &mip)) != 0)
                return (err);

        /*
         * Hold the dip associated to the MAC to prevent it from being
         * detached. For a softmac, its underlying dip is held by the
         * mi_open() callback.
         *
         * This is done to be more tolerant with some defective drivers,
         * which incorrectly handle mac_unregister() failure in their
         * xxx_detach() routine. For example, some drivers ignore the
         * failure of mac_unregister() and free all resources that
         * that are needed for data transmition.
         */
        e_ddi_hold_devi(mip->mi_dip);

        if (!(mip->mi_callbacks->mc_callbacks & MC_OPEN)) {
                *mhp = (mac_handle_t)mip;
                return (0);
        }

        /*
         * The mac perimeter is used in both mac_open and mac_close by the
         * framework to single thread the MC_OPEN/MC_CLOSE of drivers.
         */
        i_mac_perim_enter(mip);
        mip->mi_oref++;
        if (mip->mi_oref != 1 || ((err = mip->mi_open(mip->mi_driver)) == 0)) {
                *mhp = (mac_handle_t)mip;
                i_mac_perim_exit(mip);
                return (0);
        }
        mip->mi_oref--;
        ddi_release_devi(mip->mi_dip);
        mac_rele(mip);
        i_mac_perim_exit(mip);
        return (err);
}

/*
 * Open a MAC specified by its linkid.
 */
int
mac_open_by_linkid(datalink_id_t linkid, mac_handle_t *mhp)
{
        dls_dl_handle_t dlh;
        int             err;

        if ((err = dls_devnet_hold_tmp(linkid, &dlh)) != 0)
                return (err);

        dls_devnet_prop_task_wait(dlh);

        err = mac_open(dls_devnet_mac(dlh), mhp);

        dls_devnet_rele_tmp(dlh);
        return (err);
}

/*
 * Open a MAC specified by its link name.
 */
int
mac_open_by_linkname(const char *link, mac_handle_t *mhp)
{
        datalink_id_t   linkid;
        int             err;

        if ((err = dls_mgmt_get_linkid(link, &linkid)) != 0)
                return (err);
        return (mac_open_by_linkid(linkid, mhp));
}

/*
 * Close the specified MAC.
 */
void
mac_close(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        i_mac_perim_enter(mip);
        /*
         * The mac perimeter is used in both mac_open and mac_close by the
         * framework to single thread the MC_OPEN/MC_CLOSE of drivers.
         */
        if (mip->mi_callbacks->mc_callbacks & MC_OPEN) {
                ASSERT(mip->mi_oref != 0);
                if (--mip->mi_oref == 0) {
                        if ((mip->mi_callbacks->mc_callbacks & MC_CLOSE))
                                mip->mi_close(mip->mi_driver);
                }
        }
        i_mac_perim_exit(mip);
        ddi_release_devi(mip->mi_dip);
        mac_rele(mip);
}

/*
 * Misc utility functions to retrieve various information about a MAC
 * instance or a MAC client.
 */

const mac_info_t *
mac_info(mac_handle_t mh)
{
        return (&((mac_impl_t *)mh)->mi_info);
}

dev_info_t *
mac_devinfo_get(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_dip);
}

void *
mac_driver(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_driver);
}

const char *
mac_name(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_name);
}

int
mac_type(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_type->mt_type);
}

int
mac_nativetype(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_type->mt_nativetype);
}

char *
mac_client_name(mac_client_handle_t mch)
{
        return (((mac_client_impl_t *)mch)->mci_name);
}

minor_t
mac_minor(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_minor);
}

/*
 * Return the VID associated with a MAC client. This function should
 * be called for clients which are associated with only one VID.
 */
uint16_t
mac_client_vid(mac_client_handle_t mch)
{
        uint16_t                vid = VLAN_ID_NONE;
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        flow_desc_t             flow_desc;

        if (mcip->mci_nflents == 0)
                return (vid);

        ASSERT(MCIP_DATAPATH_SETUP(mcip) && mac_client_single_rcvr(mcip));

        mac_flow_get_desc(mcip->mci_flent, &flow_desc);
        if ((flow_desc.fd_mask & FLOW_LINK_VID) != 0)
                vid = flow_desc.fd_vid;

        return (vid);
}

/*
 * Return whether the specified MAC client corresponds to a VLAN VNIC.
 */
boolean_t
mac_client_is_vlan_vnic(mac_client_handle_t mch)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;

        return (((mcip->mci_state_flags & MCIS_IS_VNIC) != 0) &&
            ((mcip->mci_flent->fe_type & FLOW_PRIMARY_MAC) != 0));
}

/*
 * Return the link speed associated with the specified MAC client.
 *
 * The link speed of a MAC client is equal to the smallest value of
 * 1) the current link speed of the underlying NIC, or
 * 2) the bandwidth limit set for the MAC client.
 *
 * Note that the bandwidth limit can be higher than the speed
 * of the underlying NIC. This is allowed to avoid spurious
 * administration action failures or artifically lowering the
 * bandwidth limit of a link that may  have temporarily lowered
 * its link speed due to hardware problem or administrator action.
 */
static uint64_t
mac_client_ifspeed(mac_client_impl_t *mcip)
{
        mac_impl_t *mip = mcip->mci_mip;
        uint64_t nic_speed;

        nic_speed = mac_stat_get((mac_handle_t)mip, MAC_STAT_IFSPEED);

        if (nic_speed == 0) {
                return (0);
        } else {
                uint64_t policy_limit = (uint64_t)-1;

                if (MCIP_RESOURCE_PROPS_MASK(mcip) & MRP_MAXBW)
                        policy_limit = MCIP_RESOURCE_PROPS_MAXBW(mcip);

                return (MIN(policy_limit, nic_speed));
        }
}

/*
 * Return the link state of the specified client. If here are more
 * than one clients of the underying mac_impl_t, the link state
 * will always be UP regardless of the link state of the underlying
 * mac_impl_t. This is needed to allow the MAC clients to continue
 * to communicate with each other even when the physical link of
 * their mac_impl_t is down.
 */
static uint64_t
mac_client_link_state(mac_client_impl_t *mcip)
{
        mac_impl_t *mip = mcip->mci_mip;
        uint16_t vid;
        mac_client_impl_t *mci_list;
        mac_unicast_impl_t *mui_list, *oth_mui_list;

        /*
         * Returns LINK_STATE_UP if there are other MAC clients defined on
         * mac_impl_t which share same VLAN ID as that of mcip. Note that
         * if 'mcip' has more than one VID's then we match ANY one of the
         * VID's with other MAC client's VID's and return LINK_STATE_UP.
         */
        rw_enter(&mcip->mci_rw_lock, RW_READER);
        for (mui_list = mcip->mci_unicast_list; mui_list != NULL;
            mui_list = mui_list->mui_next) {
                vid = mui_list->mui_vid;
                for (mci_list = mip->mi_clients_list; mci_list != NULL;
                    mci_list = mci_list->mci_client_next) {
                        if (mci_list == mcip)
                                continue;
                        for (oth_mui_list = mci_list->mci_unicast_list;
                            oth_mui_list != NULL; oth_mui_list = oth_mui_list->
                            mui_next) {
                                if (vid == oth_mui_list->mui_vid) {
                                        rw_exit(&mcip->mci_rw_lock);
                                        return (LINK_STATE_UP);
                                }
                        }
                }
        }
        rw_exit(&mcip->mci_rw_lock);

        return (mac_stat_get((mac_handle_t)mip, MAC_STAT_LINK_STATE));
}

/*
 * These statistics are consumed by dladm show-link -s <vnic>,
 * dladm show-vnic -s and netstat. With the introduction of dlstat,
 * dladm show-link -s and dladm show-vnic -s witll be EOL'ed while
 * netstat will consume from kstats introduced for dlstat. This code
 * will be removed at that time.
 */

/*
 * Return the statistics of a MAC client. These statistics are different
 * then the statistics of the underlying MAC which are returned by
 * mac_stat_get().
 */
uint64_t
mac_client_stat_get(mac_client_handle_t mch, uint_t stat)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        flow_entry_t            *flent = mcip->mci_flent;
        mac_soft_ring_set_t     *mac_srs;
        mac_rx_stats_t          *mac_rx_stat;
        mac_tx_stats_t          *mac_tx_stat;
        int i;
        uint64_t val = 0;

        mac_srs = (mac_soft_ring_set_t *)(flent->fe_tx_srs);
        mac_tx_stat = &mac_srs->srs_tx.st_stat;

        switch (stat) {
        case MAC_STAT_LINK_STATE:
                val = mac_client_link_state(mcip);
                break;
        case MAC_STAT_LINK_UP:
                val = (mac_client_link_state(mcip) == LINK_STATE_UP);
                break;
        case MAC_STAT_PROMISC:
                val = mac_stat_get((mac_handle_t)mip, MAC_STAT_PROMISC);
                break;
        case MAC_STAT_LOWLINK_STATE:
                val = mac_stat_get((mac_handle_t)mip, MAC_STAT_LOWLINK_STATE);
                break;
        case MAC_STAT_IFSPEED:
                val = mac_client_ifspeed(mcip);
                break;
        case MAC_STAT_MULTIRCV:
                val = mcip->mci_misc_stat.mms_multircv;
                break;
        case MAC_STAT_BRDCSTRCV:
                val = mcip->mci_misc_stat.mms_brdcstrcv;
                break;
        case MAC_STAT_MULTIXMT:
                val = mcip->mci_misc_stat.mms_multixmt;
                break;
        case MAC_STAT_BRDCSTXMT:
                val = mcip->mci_misc_stat.mms_brdcstxmt;
                break;
        case MAC_STAT_OBYTES:
                val = mac_tx_stat->mts_obytes;
                break;
        case MAC_STAT_OPACKETS:
                val = mac_tx_stat->mts_opackets;
                break;
        case MAC_STAT_OERRORS:
                val = mac_tx_stat->mts_oerrors;
                break;
        case MAC_STAT_IPACKETS:
                for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                        mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                        mac_rx_stat = &mac_srs->srs_rx.sr_stat;
                        val += mac_rx_stat->mrs_intrcnt +
                            mac_rx_stat->mrs_pollcnt + mac_rx_stat->mrs_lclcnt;
                }
                break;
        case MAC_STAT_RBYTES:
                for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                        mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                        mac_rx_stat = &mac_srs->srs_rx.sr_stat;
                        val += mac_rx_stat->mrs_intrbytes +
                            mac_rx_stat->mrs_pollbytes +
                            mac_rx_stat->mrs_lclbytes;
                }
                break;
        case MAC_STAT_IERRORS:
                for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                        mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                        mac_rx_stat = &mac_srs->srs_rx.sr_stat;
                        val += mac_rx_stat->mrs_ierrors;
                }
                break;
        default:
                val = mac_driver_stat_default(mip, stat);
                break;
        }

        return (val);
}

/*
 * Return the statistics of the specified MAC instance.
 */
uint64_t
mac_stat_get(mac_handle_t mh, uint_t stat)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        uint64_t        val;
        int             ret;

        /*
         * The range of stat determines where it is maintained.  Stat
         * values from 0 up to (but not including) MAC_STAT_MIN are
         * mainteined by the mac module itself.  Everything else is
         * maintained by the driver.
         *
         * If the mac_impl_t being queried corresponds to a VNIC,
         * the stats need to be queried from the lower MAC client
         * corresponding to the VNIC. (The mac_link_update()
         * invoked by the driver to the lower MAC causes the *lower
         * MAC* to update its mi_linkstate, and send a notification
         * to its MAC clients. Due to the VNIC passthrough,
         * these notifications are sent to the upper MAC clients
         * of the VNIC directly, and the upper mac_impl_t of the VNIC
         * does not have a valid mi_linkstate.
         */
        if (stat < MAC_STAT_MIN && !(mip->mi_state_flags & MIS_IS_VNIC)) {
                /* these stats are maintained by the mac module itself */
                switch (stat) {
                case MAC_STAT_LINK_STATE:
                        return (mip->mi_linkstate);
                case MAC_STAT_LINK_UP:
                        return (mip->mi_linkstate == LINK_STATE_UP);
                case MAC_STAT_PROMISC:
                        return (mip->mi_devpromisc != 0);
                case MAC_STAT_LOWLINK_STATE:
                        return (mip->mi_lowlinkstate);
                default:
                        ASSERT(B_FALSE);
                }
        }

        /*
         * Call the driver to get the given statistic.
         */
        ret = mip->mi_getstat(mip->mi_driver, stat, &val);
        if (ret != 0) {
                /*
                 * The driver doesn't support this statistic.  Get the
                 * statistic's default value.
                 */
                val = mac_driver_stat_default(mip, stat);
        }
        return (val);
}

/*
 * Query hardware rx ring corresponding to the pseudo ring.
 */
uint64_t
mac_pseudo_rx_ring_stat_get(mac_ring_handle_t handle, uint_t stat)
{
        return (mac_rx_ring_stat_get(handle, stat));
}

/*
 * Query hardware tx ring corresponding to the pseudo ring.
 */
uint64_t
mac_pseudo_tx_ring_stat_get(mac_ring_handle_t handle, uint_t stat)
{
        return (mac_tx_ring_stat_get(handle, stat));
}

/*
 * Utility function which returns the VID associated with a flow entry.
 */
uint16_t
i_mac_flow_vid(flow_entry_t *flent)
{
        flow_desc_t     flow_desc;

        mac_flow_get_desc(flent, &flow_desc);

        if ((flow_desc.fd_mask & FLOW_LINK_VID) != 0)
                return (flow_desc.fd_vid);
        return (VLAN_ID_NONE);
}

/*
 * Verify the validity of the specified unicast MAC address. Returns B_TRUE
 * if the address is valid, B_FALSE otherwise (multicast address, or incorrect
 * length.
 */
boolean_t
mac_unicst_verify(mac_handle_t mh, const uint8_t *addr, uint_t len)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        /*
         * Verify the address. No lock is needed since mi_type and plugin
         * details don't change after mac_register().
         */
        if ((len != mip->mi_type->mt_addr_length) ||
            (mip->mi_type->mt_ops.mtops_unicst_verify(addr,
            mip->mi_pdata)) != 0) {
                return (B_FALSE);
        } else {
                return (B_TRUE);
        }
}

void
mac_sdu_get(mac_handle_t mh, uint_t *min_sdu, uint_t *max_sdu)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        if (min_sdu != NULL)
                *min_sdu = mip->mi_sdu_min;
        if (max_sdu != NULL)
                *max_sdu = mip->mi_sdu_max;
}

void
mac_sdu_get2(mac_handle_t mh, uint_t *min_sdu, uint_t *max_sdu,
    uint_t *multicast_sdu)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        if (min_sdu != NULL)
                *min_sdu = mip->mi_sdu_min;
        if (max_sdu != NULL)
                *max_sdu = mip->mi_sdu_max;
        if (multicast_sdu != NULL)
                *multicast_sdu = mip->mi_sdu_multicast;
}

/*
 * Update the MAC unicast address of the specified client's flows. Currently
 * only one unicast MAC unicast address is allowed per client.
 */
static void
mac_unicast_update_client_flow(mac_client_impl_t *mcip)
{
        mac_impl_t *mip = mcip->mci_mip;
        flow_entry_t *flent = mcip->mci_flent;
        mac_address_t *map = mcip->mci_unicast;
        flow_desc_t flow_desc;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        ASSERT(flent != NULL);

        mac_flow_get_desc(flent, &flow_desc);
        ASSERT(flow_desc.fd_mask & FLOW_LINK_DST);

        bcopy(map->ma_addr, flow_desc.fd_dst_mac, map->ma_len);
        mac_flow_set_desc(flent, &flow_desc);

        /*
         * The v6 local addr (used by mac protection) needs to be
         * regenerated because our mac address has changed.
         */
        mac_protect_update_v6_local_addr(mcip);

        /*
         * A MAC client could have one MAC address but multiple
         * VLANs. In that case update the flow entries corresponding
         * to all VLANs of the MAC client.
         */
        for (flent = mcip->mci_flent_list; flent != NULL;
            flent = flent->fe_client_next) {
                mac_flow_get_desc(flent, &flow_desc);
                if (!(flent->fe_type & FLOW_PRIMARY_MAC ||
                    flent->fe_type & FLOW_VNIC_MAC))
                        continue;

                bcopy(map->ma_addr, flow_desc.fd_dst_mac, map->ma_len);
                mac_flow_set_desc(flent, &flow_desc);
        }
}

/*
 * Update all clients that share the same unicast address.
 */
void
mac_unicast_update_clients(mac_impl_t *mip, mac_address_t *map)
{
        mac_client_impl_t *mcip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        /*
         * Find all clients that share the same unicast MAC address and update
         * them appropriately.
         */
        for (mcip = mip->mi_clients_list; mcip != NULL;
            mcip = mcip->mci_client_next) {
                /*
                 * Ignore clients that don't share this MAC address.
                 */
                if (map != mcip->mci_unicast)
                        continue;

                /*
                 * Update those clients with same old unicast MAC address.
                 */
                mac_unicast_update_client_flow(mcip);
        }
}

/*
 * Update the unicast MAC address of the specified VNIC MAC client.
 *
 * Check whether the operation is valid. Any of following cases should fail:
 *
 * 1. It's a VLAN type of VNIC.
 * 2. The new value is current "primary" MAC address.
 * 3. The current MAC address is shared with other clients.
 * 4. The new MAC address has been used. This case will be valid when
 *    client migration is fully supported.
 */
int
mac_vnic_unicast_set(mac_client_handle_t mch, const uint8_t *addr)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;
        mac_address_t *map = mcip->mci_unicast;
        int err;

        ASSERT(!(mip->mi_state_flags & MIS_IS_VNIC));
        ASSERT(mcip->mci_state_flags & MCIS_IS_VNIC);
        ASSERT(mcip->mci_flags != MAC_CLIENT_FLAGS_PRIMARY);

        i_mac_perim_enter(mip);

        /*
         * If this is a VLAN type of VNIC, it's using "primary" MAC address
         * of the underlying interface. Must fail here. Refer to case 1 above.
         */
        if (bcmp(map->ma_addr, mip->mi_addr, map->ma_len) == 0) {
                i_mac_perim_exit(mip);
                return (ENOTSUP);
        }

        /*
         * If the new address is the "primary" one, must fail. Refer to
         * case 2 above.
         */
        if (bcmp(addr, mip->mi_addr, map->ma_len) == 0) {
                i_mac_perim_exit(mip);
                return (EACCES);
        }

        /*
         * If the address is shared by multiple clients, must fail. Refer
         * to case 3 above.
         */
        if (mac_check_macaddr_shared(map)) {
                i_mac_perim_exit(mip);
                return (EBUSY);
        }

        /*
         * If the new address has been used, must fail for now. Refer to
         * case 4 above.
         */
        if (mac_find_macaddr(mip, (uint8_t *)addr) != NULL) {
                i_mac_perim_exit(mip);
                return (ENOTSUP);
        }

        /*
         * Update the MAC address.
         */
        err = mac_update_macaddr(map, (uint8_t *)addr);

        if (err != 0) {
                i_mac_perim_exit(mip);
                return (err);
        }

        /*
         * Update all flows of this MAC client.
         */
        mac_unicast_update_client_flow(mcip);

        i_mac_perim_exit(mip);
        return (0);
}

/*
 * Program the new primary unicast address of the specified MAC.
 *
 * Function mac_update_macaddr() takes care different types of underlying
 * MAC. If the underlying MAC is VNIC, the VNIC driver must have registerd
 * mi_unicst() entry point, that indirectly calls mac_vnic_unicast_set()
 * which will take care of updating the MAC address of the corresponding
 * MAC client.
 *
 * This is the only interface that allow the client to update the "primary"
 * MAC address of the underlying MAC. The new value must have not been
 * used by other clients.
 */
int
mac_unicast_primary_set(mac_handle_t mh, const uint8_t *addr)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_address_t *map;
        int err;

        /* verify the address validity */
        if (!mac_unicst_verify(mh, addr, mip->mi_type->mt_addr_length))
                return (EINVAL);

        i_mac_perim_enter(mip);

        /*
         * If the new value is the same as the current primary address value,
         * there's nothing to do.
         */
        if (bcmp(addr, mip->mi_addr, mip->mi_type->mt_addr_length) == 0) {
                i_mac_perim_exit(mip);
                return (0);
        }

        if (mac_find_macaddr(mip, (uint8_t *)addr) != 0) {
                i_mac_perim_exit(mip);
                return (EBUSY);
        }

        map = mac_find_macaddr(mip, mip->mi_addr);
        ASSERT(map != NULL);

        /*
         * Update the MAC address.
         */
        if (mip->mi_state_flags & MIS_IS_AGGR) {
                mac_capab_aggr_t aggr_cap;

                /*
                 * If the mac is an aggregation, other than the unicast
                 * addresses programming, aggr must be informed about this
                 * primary unicst address change to change its mac address
                 * policy to be user-specified.
                 */
                ASSERT(map->ma_type == MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED);
                VERIFY(i_mac_capab_get(mh, MAC_CAPAB_AGGR, &aggr_cap));
                err = aggr_cap.mca_unicst(mip->mi_driver, addr);
                if (err == 0)
                        bcopy(addr, map->ma_addr, map->ma_len);
        } else {
                err = mac_update_macaddr(map, (uint8_t *)addr);
        }

        if (err != 0) {
                i_mac_perim_exit(mip);
                return (err);
        }

        mac_unicast_update_clients(mip, map);

        /*
         * Save the new primary MAC address in mac_impl_t.
         */
        bcopy(addr, mip->mi_addr, mip->mi_type->mt_addr_length);

        i_mac_perim_exit(mip);

        if (err == 0)
                i_mac_notify(mip, MAC_NOTE_UNICST);

        return (err);
}

/*
 * Return the current primary MAC address of the specified MAC.
 */
void
mac_unicast_primary_get(mac_handle_t mh, uint8_t *addr)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        rw_enter(&mip->mi_rw_lock, RW_READER);
        bcopy(mip->mi_addr, addr, mip->mi_type->mt_addr_length);
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Return the secondary MAC address for the specified handle
 */
void
mac_unicast_secondary_get(mac_client_handle_t mh, uint8_t *addr)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mh;

        ASSERT(mcip->mci_unicast != NULL);
        bcopy(mcip->mci_unicast->ma_addr, addr, mcip->mci_unicast->ma_len);
}

/*
 * Return information about the use of the primary MAC address of the
 * specified MAC instance:
 *
 * - if client_name is non-NULL, it must point to a string of at
 *   least MAXNAMELEN bytes, and will be set to the name of the MAC
 *   client which uses the primary MAC address.
 *
 * - if in_use is non-NULL, used to return whether the primary MAC
 *   address is currently in use.
 */
void
mac_unicast_primary_info(mac_handle_t mh, char *client_name, boolean_t *in_use)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_client_impl_t *cur_client;

        if (in_use != NULL)
                *in_use = B_FALSE;
        if (client_name != NULL)
                bzero(client_name, MAXNAMELEN);

        /*
         * The mi_rw_lock is used to protect threads that don't hold the
         * mac perimeter to get a consistent view of the mi_clients_list.
         * Threads that modify the list must hold both the mac perimeter and
         * mi_rw_lock(RW_WRITER)
         */
        rw_enter(&mip->mi_rw_lock, RW_READER);
        for (cur_client = mip->mi_clients_list; cur_client != NULL;
            cur_client = cur_client->mci_client_next) {
                if (mac_is_primary_client(cur_client) ||
                    (mip->mi_state_flags & MIS_IS_VNIC)) {
                        rw_exit(&mip->mi_rw_lock);
                        if (in_use != NULL)
                                *in_use = B_TRUE;
                        if (client_name != NULL) {
                                bcopy(cur_client->mci_name, client_name,
                                    MAXNAMELEN);
                        }
                        return;
                }
        }
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Return the current destination MAC address of the specified MAC.
 */
boolean_t
mac_dst_get(mac_handle_t mh, uint8_t *addr)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        rw_enter(&mip->mi_rw_lock, RW_READER);
        if (mip->mi_dstaddr_set)
                bcopy(mip->mi_dstaddr, addr, mip->mi_type->mt_addr_length);
        rw_exit(&mip->mi_rw_lock);
        return (mip->mi_dstaddr_set);
}

/*
 * Add the specified MAC client to the list of clients which opened
 * the specified MAC.
 */
static void
mac_client_add(mac_client_impl_t *mcip)
{
        mac_impl_t *mip = mcip->mci_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        /* add VNIC to the front of the list */
        rw_enter(&mip->mi_rw_lock, RW_WRITER);
        mcip->mci_client_next = mip->mi_clients_list;
        mip->mi_clients_list = mcip;
        mip->mi_nclients++;
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Remove the specified MAC client from the list of clients which opened
 * the specified MAC.
 */
static void
mac_client_remove(mac_client_impl_t *mcip)
{
        mac_impl_t *mip = mcip->mci_mip;
        mac_client_impl_t **prev, *cclient;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        rw_enter(&mip->mi_rw_lock, RW_WRITER);
        prev = &mip->mi_clients_list;
        cclient = *prev;
        while (cclient != NULL && cclient != mcip) {
                prev = &cclient->mci_client_next;
                cclient = *prev;
        }
        ASSERT(cclient != NULL);
        *prev = cclient->mci_client_next;
        mip->mi_nclients--;
        rw_exit(&mip->mi_rw_lock);
}

static mac_unicast_impl_t *
mac_client_find_vid(mac_client_impl_t *mcip, uint16_t vid)
{
        mac_unicast_impl_t *muip = mcip->mci_unicast_list;

        while ((muip != NULL) && (muip->mui_vid != vid))
                muip = muip->mui_next;

        return (muip);
}

/*
 * Return whether the specified (MAC address, VID) tuple is already used by
 * one of the MAC clients associated with the specified MAC.
 */
static boolean_t
mac_addr_in_use(mac_impl_t *mip, uint8_t *mac_addr, uint16_t vid)
{
        mac_client_impl_t *client;
        mac_address_t *map;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        for (client = mip->mi_clients_list; client != NULL;
            client = client->mci_client_next) {

                /*
                 * Ignore clients that don't have unicast address.
                 */
                if (client->mci_unicast_list == NULL)
                        continue;

                map = client->mci_unicast;

                if ((bcmp(mac_addr, map->ma_addr, map->ma_len) == 0) &&
                    (mac_client_find_vid(client, vid) != NULL)) {
                        return (B_TRUE);
                }
        }

        return (B_FALSE);
}

/*
 * Generate a random MAC address. The MAC address prefix is
 * stored in the array pointed to by mac_addr, and its length, in bytes,
 * is specified by prefix_len. The least significant bits
 * after prefix_len bytes are generated, and stored after the prefix
 * in the mac_addr array.
 */
int
mac_addr_random(mac_client_handle_t mch, uint_t prefix_len,
    uint8_t *mac_addr, mac_diag_t *diag)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;
        size_t addr_len = mip->mi_type->mt_addr_length;

        if (prefix_len >= addr_len) {
                *diag = MAC_DIAG_MACPREFIXLEN_INVALID;
                return (EINVAL);
        }

        /* check the prefix value */
        if (prefix_len > 0) {
                bzero(mac_addr + prefix_len, addr_len - prefix_len);
                if (!mac_unicst_verify((mac_handle_t)mip, mac_addr,
                    addr_len)) {
                        *diag = MAC_DIAG_MACPREFIX_INVALID;
                        return (EINVAL);
                }
        }

        /* generate the MAC address */
        if (prefix_len < addr_len) {
                (void) random_get_pseudo_bytes(mac_addr +
                    prefix_len, addr_len - prefix_len);
        }

        *diag = 0;
        return (0);
}

/*
 * Set the priority range for this MAC client. This will be used to
 * determine the absolute priority for the threads created for this
 * MAC client using the specified "low", "medium" and "high" level.
 * This will also be used for any subflows on this MAC client.
 */
#define MAC_CLIENT_SET_PRIORITY_RANGE(mcip, pri) {                      \
        (mcip)->mci_min_pri = FLOW_MIN_PRIORITY(MINCLSYSPRI,    \
            MAXCLSYSPRI, (pri));                                        \
        (mcip)->mci_max_pri = FLOW_MAX_PRIORITY(MINCLSYSPRI,    \
            MAXCLSYSPRI, (mcip)->mci_min_pri);                          \
        }

/*
 * MAC client open entry point. Return a new MAC client handle. Each
 * MAC client is associated with a name, specified through the 'name'
 * argument.
 */
int
mac_client_open(mac_handle_t mh, mac_client_handle_t *mchp, char *name,
    uint16_t flags)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_client_impl_t       *mcip;
        int                     err = 0;
        boolean_t               share_desired;
        flow_entry_t            *flent = NULL;

        share_desired = (flags & MAC_OPEN_FLAGS_SHARES_DESIRED) != 0;
        *mchp = NULL;

        i_mac_perim_enter(mip);

        if (mip->mi_state_flags & MIS_IS_VNIC) {
                /*
                 * The underlying MAC is a VNIC. Return the MAC client
                 * handle of the lower MAC which was obtained by
                 * the VNIC driver when it did its mac_client_open().
                 */

                mcip = mac_vnic_lower(mip);

                /*
                 * Note that multiple mac clients share the same mcip in
                 * this case.
                 */
                if (flags & MAC_OPEN_FLAGS_EXCLUSIVE)
                        mcip->mci_state_flags |= MCIS_EXCLUSIVE;

                if (flags & MAC_OPEN_FLAGS_MULTI_PRIMARY)
                        mcip->mci_flags |= MAC_CLIENT_FLAGS_MULTI_PRIMARY;

                mip->mi_clients_list = mcip;
                i_mac_perim_exit(mip);
                *mchp = (mac_client_handle_t)mcip;

                DTRACE_PROBE2(mac__client__open__nonallocated, mac_impl_t *,
                    mcip->mci_mip, mac_client_impl_t *, mcip);

                return (err);
        }

        mcip = kmem_cache_alloc(mac_client_impl_cache, KM_SLEEP);

        mcip->mci_mip = mip;
        mcip->mci_upper_mip = NULL;
        mcip->mci_rx_fn = mac_pkt_drop;
        mcip->mci_rx_arg = NULL;
        mcip->mci_rx_p_fn = NULL;
        mcip->mci_rx_p_arg = NULL;
        mcip->mci_p_unicast_list = NULL;
        mcip->mci_direct_rx_fn = NULL;
        mcip->mci_direct_rx_arg = NULL;

        mcip->mci_unicast_list = NULL;

        if ((flags & MAC_OPEN_FLAGS_IS_VNIC) != 0)
                mcip->mci_state_flags |= MCIS_IS_VNIC;

        if ((flags & MAC_OPEN_FLAGS_EXCLUSIVE) != 0)
                mcip->mci_state_flags |= MCIS_EXCLUSIVE;

        if ((flags & MAC_OPEN_FLAGS_IS_AGGR_PORT) != 0)
                mcip->mci_state_flags |= MCIS_IS_AGGR_PORT;

        if (mip->mi_state_flags & MIS_IS_AGGR)
                mcip->mci_state_flags |= MCIS_IS_AGGR;

        if ((flags & MAC_OPEN_FLAGS_USE_DATALINK_NAME) != 0) {
                datalink_id_t   linkid;

                ASSERT(name == NULL);
                if ((err = dls_devnet_macname2linkid(mip->mi_name,
                    &linkid)) != 0) {
                        goto done;
                }
                if ((err = dls_mgmt_get_linkinfo(linkid, mcip->mci_name, NULL,
                    NULL, NULL)) != 0) {
                        /*
                         * Use mac name if dlmgmtd is not available.
                         */
                        if (err == EBADF) {
                                (void) strlcpy(mcip->mci_name, mip->mi_name,
                                    sizeof (mcip->mci_name));
                                err = 0;
                        } else {
                                goto done;
                        }
                }
                mcip->mci_state_flags |= MCIS_USE_DATALINK_NAME;
        } else {
                ASSERT(name != NULL);
                if (strlen(name) > MAXNAMELEN) {
                        err = EINVAL;
                        goto done;
                }
                (void) strlcpy(mcip->mci_name, name, sizeof (mcip->mci_name));
        }

        if (flags & MAC_OPEN_FLAGS_MULTI_PRIMARY)
                mcip->mci_flags |= MAC_CLIENT_FLAGS_MULTI_PRIMARY;

        if (flags & MAC_OPEN_FLAGS_NO_UNICAST_ADDR)
                mcip->mci_state_flags |= MCIS_NO_UNICAST_ADDR;

        mac_protect_init(mcip);

        /* the subflow table will be created dynamically */
        mcip->mci_subflow_tab = NULL;

        mcip->mci_misc_stat.mms_multircv = 0;
        mcip->mci_misc_stat.mms_brdcstrcv = 0;
        mcip->mci_misc_stat.mms_multixmt = 0;
        mcip->mci_misc_stat.mms_brdcstxmt = 0;

        /* Create an initial flow */

        err = mac_flow_create(NULL, NULL, mcip->mci_name, NULL,
            mcip->mci_state_flags & MCIS_IS_VNIC ? FLOW_VNIC_MAC :
            FLOW_PRIMARY_MAC, &flent);
        if (err != 0)
                goto done;
        mcip->mci_flent = flent;
        FLOW_MARK(flent, FE_MC_NO_DATAPATH);
        flent->fe_mcip = mcip;
        /*
         * Place initial creation reference on the flow. This reference
         * is released in the corresponding delete action viz.
         * mac_unicast_remove after waiting for all transient refs to
         * to go away. The wait happens in mac_flow_wait.
         */
        FLOW_REFHOLD(flent);

        /*
         * Do this ahead of the mac_bcast_add() below so that the mi_nclients
         * will have the right value for mac_rx_srs_setup().
         */
        mac_client_add(mcip);

        mcip->mci_share = NULL;
        if (share_desired)
                i_mac_share_alloc(mcip);

        /*
         * We will do mimimal datapath setup to allow a MAC client to
         * transmit or receive non-unicast packets without waiting
         * for mac_unicast_add.
         */
        if (mcip->mci_state_flags & MCIS_NO_UNICAST_ADDR) {
                if ((err = mac_client_datapath_setup(mcip, VLAN_ID_NONE,
                    NULL, NULL, B_TRUE, NULL)) != 0) {
                        goto done;
                }
        }

        DTRACE_PROBE2(mac__client__open__allocated, mac_impl_t *,
            mcip->mci_mip, mac_client_impl_t *, mcip);

        *mchp = (mac_client_handle_t)mcip;
        i_mac_perim_exit(mip);
        return (0);

done:
        i_mac_perim_exit(mip);
        mcip->mci_state_flags = 0;
        mcip->mci_tx_flag = 0;
        kmem_cache_free(mac_client_impl_cache, mcip);
        return (err);
}

/*
 * Close the specified MAC client handle.
 */
void
mac_client_close(mac_client_handle_t mch, uint16_t flags)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        flow_entry_t            *flent;

        i_mac_perim_enter(mip);

        if (flags & MAC_CLOSE_FLAGS_EXCLUSIVE)
                mcip->mci_state_flags &= ~MCIS_EXCLUSIVE;

        if ((mcip->mci_state_flags & MCIS_IS_VNIC) &&
            !(flags & MAC_CLOSE_FLAGS_IS_VNIC)) {
                /*
                 * This is an upper VNIC client initiated operation.
                 * The lower MAC client will be closed by the VNIC driver
                 * when the VNIC is deleted.
                 */

                i_mac_perim_exit(mip);
                return;
        }

        /* If we have only setup up minimal datapth setup, tear it down */
        if (mcip->mci_state_flags & MCIS_NO_UNICAST_ADDR) {
                mac_client_datapath_teardown((mac_client_handle_t)mcip, NULL,
                    mcip->mci_flent);
                mcip->mci_state_flags &= ~MCIS_NO_UNICAST_ADDR;
        }

        /*
         * Remove the flent associated with the MAC client
         */
        flent = mcip->mci_flent;
        mcip->mci_flent = NULL;
        FLOW_FINAL_REFRELE(flent);

        /*
         * MAC clients must remove the unicast addresses and promisc callbacks
         * they added before issuing a mac_client_close().
         */
        ASSERT(mcip->mci_unicast_list == NULL);
        ASSERT(mcip->mci_promisc_list == NULL);
        ASSERT(mcip->mci_tx_notify_cb_list == NULL);

        i_mac_share_free(mcip);
        mac_protect_fini(mcip);
        mac_client_remove(mcip);

        i_mac_perim_exit(mip);
        mcip->mci_subflow_tab = NULL;
        mcip->mci_state_flags = 0;
        mcip->mci_tx_flag = 0;
        kmem_cache_free(mac_client_impl_cache, mch);
}

/*
 * Set the rx bypass receive callback.
 */
boolean_t
mac_rx_bypass_set(mac_client_handle_t mch, mac_direct_rx_t rx_fn, void *arg1)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        /*
         * If the mac_client is a VLAN, we should not do DLS bypass and
         * instead let the packets come up via mac_rx_deliver so the vlan
         * header can be stripped.
         */
        if (mcip->mci_nvids > 0)
                return (B_FALSE);

        /*
         * These are not accessed directly in the data path, and hence
         * don't need any protection
         */
        mcip->mci_direct_rx_fn = rx_fn;
        mcip->mci_direct_rx_arg = arg1;
        return (B_TRUE);
}

/*
 * Enable/Disable rx bypass. By default, bypass is assumed to be enabled.
 */
void
mac_rx_bypass_enable(mac_client_handle_t mch)
{
        ((mac_client_impl_t *)mch)->mci_state_flags &= ~MCIS_RX_BYPASS_DISABLE;
}

void
mac_rx_bypass_disable(mac_client_handle_t mch)
{
        ((mac_client_impl_t *)mch)->mci_state_flags |= MCIS_RX_BYPASS_DISABLE;
}

/*
 * Set the receive callback for the specified MAC client. There can be
 * at most one such callback per MAC client.
 */
void
mac_rx_set(mac_client_handle_t mch, mac_rx_t rx_fn, void *arg)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t      *mip = mcip->mci_mip;
        mac_impl_t      *umip = mcip->mci_upper_mip;

        /*
         * Instead of adding an extra set of locks and refcnts in
         * the datapath at the mac client boundary, we temporarily quiesce
         * the SRS and related entities. We then change the receive function
         * without interference from any receive data thread and then reenable
         * the data flow subsequently.
         */
        i_mac_perim_enter(mip);
        mac_rx_client_quiesce(mch);

        mcip->mci_rx_fn = rx_fn;
        mcip->mci_rx_arg = arg;
        mac_rx_client_restart(mch);
        i_mac_perim_exit(mip);

        /*
         * If we're changing the rx function on the primary mac of a vnic,
         * make sure any secondary macs on the vnic are updated as well.
         */
        if (umip != NULL) {
                ASSERT((umip->mi_state_flags & MIS_IS_VNIC) != 0);
                mac_vnic_secondary_update(umip);
        }
}

/*
 * Reset the receive callback for the specified MAC client.
 */
void
mac_rx_clear(mac_client_handle_t mch)
{
        mac_rx_set(mch, mac_pkt_drop, NULL);
}

void
mac_secondary_dup(mac_client_handle_t smch, mac_client_handle_t dmch)
{
        mac_client_impl_t *smcip = (mac_client_impl_t *)smch;
        mac_client_impl_t *dmcip = (mac_client_impl_t *)dmch;
        flow_entry_t *flent = dmcip->mci_flent;

        /* This should only be called to setup secondary macs */
        ASSERT((flent->fe_type & FLOW_PRIMARY_MAC) == 0);

        mac_rx_set(dmch, smcip->mci_rx_fn, smcip->mci_rx_arg);
        dmcip->mci_promisc_list = smcip->mci_promisc_list;

        /*
         * Duplicate the primary mac resources to the secondary.
         * Since we already validated the resource controls when setting
         * them on the primary, we can ignore errors here.
         */
        (void) mac_resource_ctl_set(dmch, MCIP_RESOURCE_PROPS(smcip));
}

/*
 * Called when removing a secondary MAC. Currently only clears the promisc_list
 * since we share the primary mac's promisc_list.
 */
void
mac_secondary_cleanup(mac_client_handle_t mch)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        flow_entry_t *flent = mcip->mci_flent;

        /* This should only be called for secondary macs */
        ASSERT((flent->fe_type & FLOW_PRIMARY_MAC) == 0);
        mcip->mci_promisc_list = NULL;
}

/*
 * Walk the MAC client subflow table and updates their priority values.
 */
static int
mac_update_subflow_priority_cb(flow_entry_t *flent, void *arg)
{
        mac_flow_update_priority(arg, flent);
        return (0);
}

void
mac_update_subflow_priority(mac_client_impl_t *mcip)
{
        (void) mac_flow_walk(mcip->mci_subflow_tab,
            mac_update_subflow_priority_cb, mcip);
}

/*
 * Modify the TX or RX ring properties. We could either just move around
 * rings, i.e add/remove rings given to a client. Or this might cause the
 * client to move from hardware based to software or the other way around.
 * If we want to reset this property, then we clear the mask, additionally
 * if the client was given a non-default group we remove all rings except
 * for 1 and give it back to the default group.
 */
int
mac_client_set_rings_prop(mac_client_impl_t *mcip, mac_resource_props_t *mrp,
    mac_resource_props_t *tmrp)
{
        mac_impl_t              *mip = mcip->mci_mip;
        flow_entry_t            *flent = mcip->mci_flent;
        uint8_t                 *mac_addr;
        int                     err = 0;
        mac_group_t             *defgrp;
        mac_group_t             *group;
        mac_group_t             *ngrp;
        mac_resource_props_t    *cmrp = MCIP_RESOURCE_PROPS(mcip);
        uint_t                  ringcnt;
        boolean_t               unspec;

        if (mcip->mci_share != NULL)
                return (EINVAL);

        if (mrp->mrp_mask & MRP_RX_RINGS) {
                unspec = mrp->mrp_mask & MRP_RXRINGS_UNSPEC;
                group = flent->fe_rx_ring_group;
                defgrp = MAC_DEFAULT_RX_GROUP(mip);
                mac_addr = flent->fe_flow_desc.fd_dst_mac;

                /*
                 * No resulting change. If we are resetting on a client on
                 * which there was no rx rings property. For dynamic group
                 * if we are setting the same number of rings already set.
                 * For static group if we are requesting a group again.
                 */
                if (mrp->mrp_mask & MRP_RINGS_RESET) {
                        if (!(tmrp->mrp_mask & MRP_RX_RINGS))
                                return (0);
                } else {
                        if (unspec) {
                                if (tmrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                                        return (0);
                        } else if (mip->mi_rx_group_type ==
                            MAC_GROUP_TYPE_DYNAMIC) {
                                if ((tmrp->mrp_mask & MRP_RX_RINGS) &&
                                    !(tmrp->mrp_mask & MRP_RXRINGS_UNSPEC) &&
                                    mrp->mrp_nrxrings == tmrp->mrp_nrxrings) {
                                        return (0);
                                }
                        }
                }
                /* Resetting the prop */
                if (mrp->mrp_mask & MRP_RINGS_RESET) {
                        /*
                         * We will just keep one ring and give others back if
                         * we are not the primary. For the primary we give
                         * all the rings in the default group except the
                         * default ring. If it is a static group, then
                         * we don't do anything, but clear the MRP_RX_RINGS
                         * flag.
                         */
                        if (group != defgrp) {
                                if (mip->mi_rx_group_type ==
                                    MAC_GROUP_TYPE_DYNAMIC) {
                                        /*
                                         * This group has reserved rings
                                         * that need to be released now,
                                         * so does the group.
                                         */
                                        MAC_RX_RING_RELEASED(mip,
                                            group->mrg_cur_count);
                                        MAC_RX_GRP_RELEASED(mip);
                                        if ((flent->fe_type &
                                            FLOW_PRIMARY_MAC) != 0) {
                                                if (mip->mi_nactiveclients ==
                                                    1) {
                                                        (void)
                                                            mac_rx_switch_group(
                                                            mcip, group,
                                                            defgrp);
                                                        return (0);
                                                } else {
                                                        cmrp->mrp_nrxrings =
                                                            group->
                                                            mrg_cur_count +
                                                            defgrp->
                                                            mrg_cur_count - 1;
                                                }
                                        } else {
                                                cmrp->mrp_nrxrings = 1;
                                        }
                                        (void) mac_group_ring_modify(mcip,
                                            group, defgrp);
                                } else {
                                        /*
                                         * If this is a static group, we
                                         * need to release the group. The
                                         * client will remain in the same
                                         * group till some other client
                                         * needs this group.
                                         */
                                        MAC_RX_GRP_RELEASED(mip);
                                }
                        /* Let check if we can give this an excl group */
                        } else if (group == defgrp) {
                                ngrp =  mac_reserve_rx_group(mcip, mac_addr,
                                    B_TRUE);
                                /* Couldn't give it a group, that's fine */
                                if (ngrp == NULL)
                                        return (0);
                                /* Switch to H/W */
                                if (mac_rx_switch_group(mcip, defgrp, ngrp) !=
                                    0) {
                                        mac_stop_group(ngrp);
                                        return (0);
                                }
                        }
                        /*
                         * If the client is in the default group, we will
                         * just clear the MRP_RX_RINGS and leave it as
                         * it rather than look for an exclusive group
                         * for it.
                         */
                        return (0);
                }

                if (group == defgrp && ((mrp->mrp_nrxrings > 0) || unspec)) {
                        ngrp =  mac_reserve_rx_group(mcip, mac_addr, B_TRUE);
                        if (ngrp == NULL)
                                return (ENOSPC);

                        /* Switch to H/W */
                        if (mac_rx_switch_group(mcip, defgrp, ngrp) != 0) {
                                mac_release_rx_group(mcip, ngrp);
                                return (ENOSPC);
                        }
                        MAC_RX_GRP_RESERVED(mip);
                        if (mip->mi_rx_group_type == MAC_GROUP_TYPE_DYNAMIC)
                                MAC_RX_RING_RESERVED(mip, ngrp->mrg_cur_count);
                } else if (group != defgrp && !unspec &&
                    mrp->mrp_nrxrings == 0) {
                        /* Switch to S/W */
                        ringcnt = group->mrg_cur_count;
                        if (mac_rx_switch_group(mcip, group, defgrp) != 0)
                                return (ENOSPC);
                        if (tmrp->mrp_mask & MRP_RX_RINGS) {
                                MAC_RX_GRP_RELEASED(mip);
                                if (mip->mi_rx_group_type ==
                                    MAC_GROUP_TYPE_DYNAMIC) {
                                        MAC_RX_RING_RELEASED(mip, ringcnt);
                                }
                        }
                } else if (group != defgrp && mip->mi_rx_group_type ==
                    MAC_GROUP_TYPE_DYNAMIC) {
                        ringcnt = group->mrg_cur_count;
                        err = mac_group_ring_modify(mcip, group, defgrp);
                        if (err != 0)
                                return (err);
                        /*
                         * Update the accounting. If this group
                         * already had explicitly reserved rings,
                         * we need to update the rings based on
                         * the new ring count. If this group
                         * had not explicitly reserved rings,
                         * then we just reserve the rings asked for
                         * and reserve the group.
                         */
                        if (tmrp->mrp_mask & MRP_RX_RINGS) {
                                if (ringcnt > group->mrg_cur_count) {
                                        MAC_RX_RING_RELEASED(mip,
                                            ringcnt - group->mrg_cur_count);
                                } else {
                                        MAC_RX_RING_RESERVED(mip,
                                            group->mrg_cur_count - ringcnt);
                                }
                        } else {
                                MAC_RX_RING_RESERVED(mip, group->mrg_cur_count);
                                MAC_RX_GRP_RESERVED(mip);
                        }
                }
        }
        if (mrp->mrp_mask & MRP_TX_RINGS) {
                unspec = mrp->mrp_mask & MRP_TXRINGS_UNSPEC;
                group = flent->fe_tx_ring_group;
                defgrp = MAC_DEFAULT_TX_GROUP(mip);

                /*
                 * For static groups we only allow rings=0 or resetting the
                 * rings property.
                 */
                if (mrp->mrp_ntxrings > 0 &&
                    mip->mi_tx_group_type != MAC_GROUP_TYPE_DYNAMIC) {
                        return (ENOTSUP);
                }
                if (mrp->mrp_mask & MRP_RINGS_RESET) {
                        if (!(tmrp->mrp_mask & MRP_TX_RINGS))
                                return (0);
                } else {
                        if (unspec) {
                                if (tmrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                                        return (0);
                        } else if (mip->mi_tx_group_type ==
                            MAC_GROUP_TYPE_DYNAMIC) {
                                if ((tmrp->mrp_mask & MRP_TX_RINGS) &&
                                    !(tmrp->mrp_mask & MRP_TXRINGS_UNSPEC) &&
                                    mrp->mrp_ntxrings == tmrp->mrp_ntxrings) {
                                        return (0);
                                }
                        }
                }
                /* Resetting the prop */
                if (mrp->mrp_mask & MRP_RINGS_RESET) {
                        if (group != defgrp) {
                                if (mip->mi_tx_group_type ==
                                    MAC_GROUP_TYPE_DYNAMIC) {
                                        ringcnt = group->mrg_cur_count;
                                        if ((flent->fe_type &
                                            FLOW_PRIMARY_MAC) != 0) {
                                                mac_tx_client_quiesce(
                                                    (mac_client_handle_t)
                                                    mcip);
                                                mac_tx_switch_group(mcip,
                                                    group, defgrp);
                                                mac_tx_client_restart(
                                                    (mac_client_handle_t)
                                                    mcip);
                                                MAC_TX_GRP_RELEASED(mip);
                                                MAC_TX_RING_RELEASED(mip,
                                                    ringcnt);
                                                return (0);
                                        }
                                        cmrp->mrp_ntxrings = 1;
                                        (void) mac_group_ring_modify(mcip,
                                            group, defgrp);
                                        /*
                                         * This group has reserved rings
                                         * that need to be released now.
                                         */
                                        MAC_TX_RING_RELEASED(mip, ringcnt);
                                }
                                /*
                                 * If this is a static group, we
                                 * need to release the group. The
                                 * client will remain in the same
                                 * group till some other client
                                 * needs this group.
                                 */
                                MAC_TX_GRP_RELEASED(mip);
                        } else if (group == defgrp &&
                            (flent->fe_type & FLOW_PRIMARY_MAC) == 0) {
                                ngrp = mac_reserve_tx_group(mcip, B_TRUE);
                                if (ngrp == NULL)
                                        return (0);
                                mac_tx_client_quiesce(
                                    (mac_client_handle_t)mcip);
                                mac_tx_switch_group(mcip, defgrp, ngrp);
                                mac_tx_client_restart(
                                    (mac_client_handle_t)mcip);
                        }
                        /*
                         * If the client is in the default group, we will
                         * just clear the MRP_TX_RINGS and leave it as
                         * it rather than look for an exclusive group
                         * for it.
                         */
                        return (0);
                }

                /* Switch to H/W */
                if (group == defgrp && ((mrp->mrp_ntxrings > 0) || unspec)) {
                        ngrp =  mac_reserve_tx_group(mcip, B_TRUE);
                        if (ngrp == NULL)
                                return (ENOSPC);
                        mac_tx_client_quiesce((mac_client_handle_t)mcip);
                        mac_tx_switch_group(mcip, defgrp, ngrp);
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        MAC_TX_GRP_RESERVED(mip);
                        if (mip->mi_tx_group_type == MAC_GROUP_TYPE_DYNAMIC)
                                MAC_TX_RING_RESERVED(mip, ngrp->mrg_cur_count);
                /* Switch to S/W */
                } else if (group != defgrp && !unspec &&
                    mrp->mrp_ntxrings == 0) {
                        /* Switch to S/W */
                        ringcnt = group->mrg_cur_count;
                        mac_tx_client_quiesce((mac_client_handle_t)mcip);
                        mac_tx_switch_group(mcip, group, defgrp);
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        if (tmrp->mrp_mask & MRP_TX_RINGS) {
                                MAC_TX_GRP_RELEASED(mip);
                                if (mip->mi_tx_group_type ==
                                    MAC_GROUP_TYPE_DYNAMIC) {
                                        MAC_TX_RING_RELEASED(mip, ringcnt);
                                }
                        }
                } else if (group != defgrp && mip->mi_tx_group_type ==
                    MAC_GROUP_TYPE_DYNAMIC) {
                        ringcnt = group->mrg_cur_count;
                        err = mac_group_ring_modify(mcip, group, defgrp);
                        if (err != 0)
                                return (err);
                        /*
                         * Update the accounting. If this group
                         * already had explicitly reserved rings,
                         * we need to update the rings based on
                         * the new ring count. If this group
                         * had not explicitly reserved rings,
                         * then we just reserve the rings asked for
                         * and reserve the group.
                         */
                        if (tmrp->mrp_mask & MRP_TX_RINGS) {
                                if (ringcnt > group->mrg_cur_count) {
                                        MAC_TX_RING_RELEASED(mip,
                                            ringcnt - group->mrg_cur_count);
                                } else {
                                        MAC_TX_RING_RESERVED(mip,
                                            group->mrg_cur_count - ringcnt);
                                }
                        } else {
                                MAC_TX_RING_RESERVED(mip, group->mrg_cur_count);
                                MAC_TX_GRP_RESERVED(mip);
                        }
                }
        }
        return (0);
}

/*
 * When the MAC client is being brought up (i.e. we do a unicast_add) we need
 * to initialize the cpu and resource control structure in the
 * mac_client_impl_t from the mac_impl_t (i.e if there are any cached
 * properties before the flow entry for the unicast address was created).
 */
static int
mac_resource_ctl_set(mac_client_handle_t mch, mac_resource_props_t *mrp)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = (mac_impl_t *)mcip->mci_mip;
        mac_impl_t              *umip = mcip->mci_upper_mip;
        int                     err = 0;
        flow_entry_t            *flent = mcip->mci_flent;
        mac_resource_props_t    *omrp, *nmrp = MCIP_RESOURCE_PROPS(mcip);

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        err = mac_validate_props(mcip->mci_state_flags & MCIS_IS_VNIC ?
            mcip->mci_upper_mip : mip, mrp);
        if (err != 0)
                return (err);

        /*
         * Copy over the existing properties since mac_update_resources
         * will modify the client's mrp. Currently, the saved property
         * is used to determine the difference between existing and
         * modified rings property.
         */
        omrp = kmem_zalloc(sizeof (*omrp), KM_SLEEP);
        bcopy(nmrp, omrp, sizeof (*omrp));
        mac_update_resources(mrp, MCIP_RESOURCE_PROPS(mcip), B_FALSE);
        if (MCIP_DATAPATH_SETUP(mcip)) {
                /*
                 * We support rings only for primary client when there are
                 * multiple clients sharing the same MAC address (e.g. VLAN).
                 */
                if (mrp->mrp_mask & MRP_RX_RINGS ||
                    mrp->mrp_mask & MRP_TX_RINGS) {

                        if ((err = mac_client_set_rings_prop(mcip, mrp,
                            omrp)) != 0) {
                                if (omrp->mrp_mask & MRP_RX_RINGS) {
                                        nmrp->mrp_mask |= MRP_RX_RINGS;
                                        nmrp->mrp_nrxrings = omrp->mrp_nrxrings;
                                } else {
                                        nmrp->mrp_mask &= ~MRP_RX_RINGS;
                                        nmrp->mrp_nrxrings = 0;
                                }
                                if (omrp->mrp_mask & MRP_TX_RINGS) {
                                        nmrp->mrp_mask |= MRP_TX_RINGS;
                                        nmrp->mrp_ntxrings = omrp->mrp_ntxrings;
                                } else {
                                        nmrp->mrp_mask &= ~MRP_TX_RINGS;
                                        nmrp->mrp_ntxrings = 0;
                                }
                                if (omrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                                        omrp->mrp_mask |= MRP_RXRINGS_UNSPEC;
                                else
                                        omrp->mrp_mask &= ~MRP_RXRINGS_UNSPEC;

                                if (omrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                                        omrp->mrp_mask |= MRP_TXRINGS_UNSPEC;
                                else
                                        omrp->mrp_mask &= ~MRP_TXRINGS_UNSPEC;
                                kmem_free(omrp, sizeof (*omrp));
                                return (err);
                        }

                        /*
                         * If we modified the rings property of the primary
                         * we need to update the property fields of its
                         * VLANs as they inherit the primary's properites.
                         */
                        if (mac_is_primary_client(mcip)) {
                                mac_set_prim_vlan_rings(mip,
                                    MCIP_RESOURCE_PROPS(mcip));
                        }
                }
                /*
                 * We have to set this prior to calling mac_flow_modify.
                 */
                if (mrp->mrp_mask & MRP_PRIORITY) {
                        if (mrp->mrp_priority == MPL_RESET) {
                                MAC_CLIENT_SET_PRIORITY_RANGE(mcip,
                                    MPL_LINK_DEFAULT);
                        } else {
                                MAC_CLIENT_SET_PRIORITY_RANGE(mcip,
                                    mrp->mrp_priority);
                        }
                }

                mac_flow_modify(mip->mi_flow_tab, flent, mrp);
                if (mrp->mrp_mask & MRP_PRIORITY)
                        mac_update_subflow_priority(mcip);

                /* Apply these resource settings to any secondary macs */
                if (umip != NULL) {
                        ASSERT((umip->mi_state_flags & MIS_IS_VNIC) != 0);
                        mac_vnic_secondary_update(umip);
                }
        }
        kmem_free(omrp, sizeof (*omrp));
        return (0);
}

static int
mac_unicast_flow_create(mac_client_impl_t *mcip, uint8_t *mac_addr,
    uint16_t vid, boolean_t is_primary, boolean_t first_flow,
    flow_entry_t **flent, mac_resource_props_t *mrp)
{
        mac_impl_t      *mip = (mac_impl_t *)mcip->mci_mip;
        flow_desc_t     flow_desc;
        char            flowname[MAXFLOWNAMELEN];
        int             err;
        uint_t          flent_flags;

        /*
         * First unicast address being added, create a new flow
         * for that MAC client.
         */
        bzero(&flow_desc, sizeof (flow_desc));

        ASSERT(mac_addr != NULL ||
            (mcip->mci_state_flags & MCIS_NO_UNICAST_ADDR));
        if (mac_addr != NULL) {
                flow_desc.fd_mac_len = mip->mi_type->mt_addr_length;
                bcopy(mac_addr, flow_desc.fd_dst_mac, flow_desc.fd_mac_len);
        }
        flow_desc.fd_mask = FLOW_LINK_DST;
        if (vid != 0) {
                flow_desc.fd_vid = vid;
                flow_desc.fd_mask |= FLOW_LINK_VID;
        }

        /*
         * XXX-nicolas. For now I'm keeping the FLOW_PRIMARY_MAC
         * and FLOW_VNIC. Even though they're a hack inherited
         * from the SRS code, we'll keep them for now. They're currently
         * consumed by mac_datapath_setup() to create the SRS.
         * That code should be eventually moved out of
         * mac_datapath_setup() and moved to a mac_srs_create()
         * function of some sort to keep things clean.
         *
         * Also, there's no reason why the SRS for the primary MAC
         * client should be different than any other MAC client. Until
         * this is cleaned-up, we support only one MAC unicast address
         * per client.
         *
         * We set FLOW_PRIMARY_MAC for the primary MAC address,
         * FLOW_VNIC for everything else.
         */
        if (is_primary)
                flent_flags = FLOW_PRIMARY_MAC;
        else
                flent_flags = FLOW_VNIC_MAC;

        /*
         * For the first flow we use the mac client's name - mci_name, for
         * subsequent ones we just create a name with the vid. This is
         * so that we can add these flows to the same flow table. This is
         * fine as the flow name (except for the one with the mac client's
         * name) is not visible. When the first flow is removed, we just replace
         * its fdesc with another from the list, so we will still retain the
         * flent with the MAC client's flow name.
         */
        if (first_flow) {
                bcopy(mcip->mci_name, flowname, MAXFLOWNAMELEN);
        } else {
                (void) sprintf(flowname, "%s%u", mcip->mci_name, vid);
                flent_flags = FLOW_NO_STATS;
        }

        if ((err = mac_flow_create(&flow_desc, mrp, flowname, NULL,
            flent_flags, flent)) != 0)
                return (err);

        mac_misc_stat_create(*flent);
        FLOW_MARK(*flent, FE_INCIPIENT);
        (*flent)->fe_mcip = mcip;

        /*
         * Place initial creation reference on the flow. This reference
         * is released in the corresponding delete action viz.
         * mac_unicast_remove after waiting for all transient refs to
         * to go away. The wait happens in mac_flow_wait.
         * We have already held the reference in mac_client_open().
         */
        if (!first_flow)
                FLOW_REFHOLD(*flent);
        return (0);
}

/* Refresh the multicast grouping for this VID. */
int
mac_client_update_mcast(void *arg, boolean_t add, const uint8_t *addrp)
{
        flow_entry_t            *flent = arg;
        mac_client_impl_t       *mcip = flent->fe_mcip;
        uint16_t                vid;
        flow_desc_t             flow_desc;

        mac_flow_get_desc(flent, &flow_desc);
        vid = (flow_desc.fd_mask & FLOW_LINK_VID) != 0 ?
            flow_desc.fd_vid : VLAN_ID_NONE;

        /*
         * We don't call mac_multicast_add()/mac_multicast_remove() as
         * we want to add/remove for this specific vid.
         */
        if (add) {
                return (mac_bcast_add(mcip, addrp, vid,
                    MAC_ADDRTYPE_MULTICAST));
        } else {
                mac_bcast_delete(mcip, addrp, vid);
                return (0);
        }
}

static void
mac_update_single_active_client(mac_impl_t *mip)
{
        mac_client_impl_t *client = NULL;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        rw_enter(&mip->mi_rw_lock, RW_WRITER);
        if (mip->mi_nactiveclients == 1) {
                /*
                 * Find the one active MAC client from the list of MAC
                 * clients. The active MAC client has at least one
                 * unicast address.
                 */
                for (client = mip->mi_clients_list; client != NULL;
                    client = client->mci_client_next) {
                        if (client->mci_unicast_list != NULL)
                                break;
                }
                ASSERT(client != NULL);
        }

        /*
         * mi_single_active_client is protected by the MAC impl's read/writer
         * lock, which allows mac_rx() to check the value of that pointer
         * as a reader.
         */
        mip->mi_single_active_client = client;
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Set up the data path. Called from i_mac_unicast_add after having
 * done all the validations including making sure this is an active
 * client (i.e that is ready to process packets.)
 */
static int
mac_client_datapath_setup(mac_client_impl_t *mcip, uint16_t vid,
    uint8_t *mac_addr, mac_resource_props_t *mrp, boolean_t isprimary,
    mac_unicast_impl_t *muip)
{
        mac_impl_t      *mip = mcip->mci_mip;
        boolean_t       mac_started = B_FALSE;
        boolean_t       bcast_added = B_FALSE;
        boolean_t       nactiveclients_added = B_FALSE;
        flow_entry_t    *flent;
        int             err = 0;
        boolean_t       no_unicast;

        no_unicast = mcip->mci_state_flags & MCIS_NO_UNICAST_ADDR;

        if ((err = mac_start((mac_handle_t)mip)) != 0)
                goto bail;

        mac_started = B_TRUE;

        /* add the MAC client to the broadcast address group by default */
        if (mip->mi_type->mt_brdcst_addr != NULL) {
                err = mac_bcast_add(mcip, mip->mi_type->mt_brdcst_addr, vid,
                    MAC_ADDRTYPE_BROADCAST);
                if (err != 0)
                        goto bail;
                bcast_added = B_TRUE;
        }

        /*
         * If this is the first unicast address addition for this
         * client, reuse the pre-allocated larval flow entry associated with
         * the MAC client.
         */
        flent = (mcip->mci_nflents == 0) ? mcip->mci_flent : NULL;

        /* We are configuring the unicast flow now */
        if (!MCIP_DATAPATH_SETUP(mcip)) {

                if (mrp != NULL) {
                        MAC_CLIENT_SET_PRIORITY_RANGE(mcip,
                            (mrp->mrp_mask & MRP_PRIORITY) ? mrp->mrp_priority :
                            MPL_LINK_DEFAULT);
                }
                if ((err = mac_unicast_flow_create(mcip, mac_addr, vid,
                    isprimary, B_TRUE, &flent, mrp)) != 0)
                        goto bail;

                mip->mi_nactiveclients++;
                nactiveclients_added = B_TRUE;

                /*
                 * This will allocate the RX ring group if possible for the
                 * flow and program the software classifier as needed.
                 */
                if ((err = mac_datapath_setup(mcip, flent, SRST_LINK)) != 0)
                        goto bail;

                if (no_unicast)
                        goto done_setup;
                /*
                 * The unicast MAC address must have been added successfully.
                 */
                ASSERT(mcip->mci_unicast != NULL);
                /*
                 * Push down the sub-flows that were defined on this link
                 * hitherto. The flows are added to the active flow table
                 * and SRS, softrings etc. are created as needed.
                 */
                mac_link_init_flows((mac_client_handle_t)mcip);
        } else {
                mac_address_t *map = mcip->mci_unicast;

                ASSERT(!no_unicast);
                /*
                 * A unicast flow already exists for that MAC client,
                 * this flow must be the same mac address but with
                 * different VID. It has been checked by mac_addr_in_use().
                 *
                 * We will use the SRS etc. from the mci_flent. Note that
                 * We don't need to create kstat for this as except for
                 * the fdesc, everything will be used from in the 1st flent.
                 */

                if (bcmp(mac_addr, map->ma_addr, map->ma_len) != 0) {
                        err = EINVAL;
                        goto bail;
                }

                if ((err = mac_unicast_flow_create(mcip, mac_addr, vid,
                    isprimary, B_FALSE, &flent, NULL)) != 0) {
                        goto bail;
                }
                if ((err = mac_flow_add(mip->mi_flow_tab, flent)) != 0) {
                        FLOW_FINAL_REFRELE(flent);
                        goto bail;
                }

                /* update the multicast group for this vid */
                mac_client_bcast_refresh(mcip, mac_client_update_mcast,
                    (void *)flent, B_TRUE);

        }

        /* populate the shared MAC address */
        muip->mui_map = mcip->mci_unicast;

        rw_enter(&mcip->mci_rw_lock, RW_WRITER);
        muip->mui_next = mcip->mci_unicast_list;
        mcip->mci_unicast_list = muip;
        rw_exit(&mcip->mci_rw_lock);

done_setup:
        /*
         * First add the flent to the flow list of this mcip. Then set
         * the mip's mi_single_active_client if needed. The Rx path assumes
         * that mip->mi_single_active_client will always have an associated
         * flent.
         */
        mac_client_add_to_flow_list(mcip, flent);
        if (nactiveclients_added)
                mac_update_single_active_client(mip);
        /*
         * Trigger a renegotiation of the capabilities when the number of
         * active clients changes from 1 to 2, since some of the capabilities
         * might have to be disabled. Also send a MAC_NOTE_LINK notification
         * to all the MAC clients whenever physical link is DOWN.
         */
        if (mip->mi_nactiveclients == 2) {
                mac_capab_update((mac_handle_t)mip);
                mac_virtual_link_update(mip);
        }
        /*
         * Now that the setup is complete, clear the INCIPIENT flag.
         * The flag was set to avoid incoming packets seeing inconsistent
         * structures while the setup was in progress. Clear the mci_tx_flag
         * by calling mac_tx_client_block. It is possible that
         * mac_unicast_remove was called prior to this mac_unicast_add which
         * could have set the MCI_TX_QUIESCE flag.
         */
        if (flent->fe_rx_ring_group != NULL)
                mac_rx_group_unmark(flent->fe_rx_ring_group, MR_INCIPIENT);
        FLOW_UNMARK(flent, FE_INCIPIENT);
        FLOW_UNMARK(flent, FE_MC_NO_DATAPATH);
        mac_tx_client_unblock(mcip);
        return (0);
bail:
        if (bcast_added)
                mac_bcast_delete(mcip, mip->mi_type->mt_brdcst_addr, vid);

        if (nactiveclients_added)
                mip->mi_nactiveclients--;

        if (mac_started)
                mac_stop((mac_handle_t)mip);

        return (err);
}

/*
 * Return the passive primary MAC client, if present. The passive client is
 * a stand-by client that has the same unicast address as another that is
 * currenly active. Once the active client goes away, the passive client
 * becomes active.
 */
static mac_client_impl_t *
mac_get_passive_primary_client(mac_impl_t *mip)
{
        mac_client_impl_t       *mcip;

        for (mcip = mip->mi_clients_list; mcip != NULL;
            mcip = mcip->mci_client_next) {
                if (mac_is_primary_client(mcip) &&
                    (mcip->mci_flags & MAC_CLIENT_FLAGS_PASSIVE_PRIMARY) != 0) {
                        return (mcip);
                }
        }
        return (NULL);
}

/*
 * Add a new unicast address to the MAC client.
 *
 * The MAC address can be specified either by value, or the MAC client
 * can specify that it wants to use the primary MAC address of the
 * underlying MAC. See the introductory comments at the beginning
 * of this file for more more information on primary MAC addresses.
 *
 * Note also the tuple (MAC address, VID) must be unique
 * for the MAC clients defined on top of the same underlying MAC
 * instance, unless the MAC_UNICAST_NODUPCHECK is specified.
 *
 * In no case can a client use the PVID for the MAC, if the MAC has one set.
 */
int
i_mac_unicast_add(mac_client_handle_t mch, uint8_t *mac_addr, uint16_t flags,
    mac_unicast_handle_t *mah, uint16_t vid, mac_diag_t *diag)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        int                     err;
        uint_t                  mac_len = mip->mi_type->mt_addr_length;
        boolean_t               check_dups = !(flags & MAC_UNICAST_NODUPCHECK);
        boolean_t               fastpath_disabled = B_FALSE;
        boolean_t               is_primary = (flags & MAC_UNICAST_PRIMARY);
        boolean_t               is_unicast_hw = (flags & MAC_UNICAST_HW);
        mac_resource_props_t    *mrp;
        boolean_t               passive_client = B_FALSE;
        mac_unicast_impl_t      *muip;
        boolean_t               is_vnic_primary =
            (flags & MAC_UNICAST_VNIC_PRIMARY);

        /* when VID is non-zero, the underlying MAC can not be VNIC */
        ASSERT(!((mip->mi_state_flags & MIS_IS_VNIC) && (vid != 0)));

        /*
         * Can't unicast add if the client asked only for minimal datapath
         * setup.
         */
        if (mcip->mci_state_flags & MCIS_NO_UNICAST_ADDR)
                return (ENOTSUP);

        /*
         * Check for an attempted use of the current Port VLAN ID, if enabled.
         * No client may use it.
         */
        if (mip->mi_pvid != 0 && vid == mip->mi_pvid)
                return (EBUSY);

        /*
         * Check whether it's the primary client and flag it.
         */
        if (!(mcip->mci_state_flags & MCIS_IS_VNIC) && is_primary && vid == 0)
                mcip->mci_flags |= MAC_CLIENT_FLAGS_PRIMARY;

        /*
         * is_vnic_primary is true when we come here as a VLAN VNIC
         * which uses the primary mac client's address but with a non-zero
         * VID. In this case the MAC address is not specified by an upper
         * MAC client.
         */
        if ((mcip->mci_state_flags & MCIS_IS_VNIC) && is_primary &&
            !is_vnic_primary) {
                /*
                 * The address is being set by the upper MAC client
                 * of a VNIC. The MAC address was already set by the
                 * VNIC driver during VNIC creation.
                 *
                 * Note: a VNIC has only one MAC address. We return
                 * the MAC unicast address handle of the lower MAC client
                 * corresponding to the VNIC. We allocate a new entry
                 * which is flagged appropriately, so that mac_unicast_remove()
                 * doesn't attempt to free the original entry that
                 * was allocated by the VNIC driver.
                 */
                ASSERT(mcip->mci_unicast != NULL);

                /* Check for VLAN flags, if present */
                if ((flags & MAC_UNICAST_TAG_DISABLE) != 0)
                        mcip->mci_state_flags |= MCIS_TAG_DISABLE;

                if ((flags & MAC_UNICAST_STRIP_DISABLE) != 0)
                        mcip->mci_state_flags |= MCIS_STRIP_DISABLE;

                if ((flags & MAC_UNICAST_DISABLE_TX_VID_CHECK) != 0)
                        mcip->mci_state_flags |= MCIS_DISABLE_TX_VID_CHECK;

                /*
                 * Ensure that the primary unicast address of the VNIC
                 * is added only once unless we have the
                 * MAC_CLIENT_FLAGS_MULTI_PRIMARY set (and this is not
                 * a passive MAC client).
                 */
                if ((mcip->mci_flags & MAC_CLIENT_FLAGS_VNIC_PRIMARY) != 0) {
                        if ((mcip->mci_flags &
                            MAC_CLIENT_FLAGS_MULTI_PRIMARY) == 0 ||
                            (mcip->mci_flags &
                            MAC_CLIENT_FLAGS_PASSIVE_PRIMARY) != 0) {
                                return (EBUSY);
                        }
                        mcip->mci_flags |= MAC_CLIENT_FLAGS_PASSIVE_PRIMARY;
                        passive_client = B_TRUE;
                }

                mcip->mci_flags |= MAC_CLIENT_FLAGS_VNIC_PRIMARY;

                /*
                 * Create a handle for vid 0.
                 */
                ASSERT(vid == 0);
                muip = kmem_zalloc(sizeof (mac_unicast_impl_t), KM_SLEEP);
                muip->mui_vid = vid;
                *mah = (mac_unicast_handle_t)muip;
                /*
                 * This will be used by the caller to defer setting the
                 * rx functions.
                 */
                if (passive_client)
                        return (EAGAIN);
                return (0);
        }

        /* primary MAC clients cannot be opened on top of anchor VNICs */
        if ((is_vnic_primary || is_primary) &&
            i_mac_capab_get((mac_handle_t)mip, MAC_CAPAB_ANCHOR_VNIC, NULL)) {
                return (ENXIO);
        }

        /*
         * If this is a VNIC/VLAN, disable softmac fast-path.
         */
        if (mcip->mci_state_flags & MCIS_IS_VNIC) {
                err = mac_fastpath_disable((mac_handle_t)mip);
                if (err != 0)
                        return (err);
                fastpath_disabled = B_TRUE;
        }

        /*
         * Return EBUSY if:
         *  - there is an exclusively active mac client exists.
         *  - this is an exclusive active mac client but
         *      a. there is already active mac clients exist, or
         *      b. fastpath streams are already plumbed on this legacy device
         *  - the mac creator has disallowed active mac clients.
         */
        if (mip->mi_state_flags & (MIS_EXCLUSIVE|MIS_NO_ACTIVE)) {
                if (fastpath_disabled)
                        mac_fastpath_enable((mac_handle_t)mip);
                return (EBUSY);
        }

        if (mcip->mci_state_flags & MCIS_EXCLUSIVE) {
                ASSERT(!fastpath_disabled);
                if (mip->mi_nactiveclients != 0)
                        return (EBUSY);

                if ((mip->mi_state_flags & MIS_LEGACY) &&
                    !(mip->mi_capab_legacy.ml_active_set(mip->mi_driver))) {
                        return (EBUSY);
                }
                mip->mi_state_flags |= MIS_EXCLUSIVE;
        }

        mrp = kmem_zalloc(sizeof (*mrp), KM_SLEEP);
        if (is_primary && !(mcip->mci_state_flags & (MCIS_IS_VNIC |
            MCIS_IS_AGGR_PORT))) {
                /*
                 * Apply the property cached in the mac_impl_t to the primary
                 * mac client. If the mac client is a VNIC or an aggregation
                 * port, its property should be set in the mcip when the
                 * VNIC/aggr was created.
                 */
                mac_get_resources((mac_handle_t)mip, mrp);
                (void) mac_client_set_resources(mch, mrp);
        } else if (mcip->mci_state_flags & MCIS_IS_VNIC) {
                /*
                 * This is a primary VLAN client, we don't support
                 * specifying rings property for this as it inherits the
                 * rings property from its MAC.
                 */
                if (is_vnic_primary) {
                        mac_resource_props_t    *vmrp;

                        vmrp = MCIP_RESOURCE_PROPS(mcip);
                        if (vmrp->mrp_mask & MRP_RX_RINGS ||
                            vmrp->mrp_mask & MRP_TX_RINGS) {
                                if (fastpath_disabled)
                                        mac_fastpath_enable((mac_handle_t)mip);
                                kmem_free(mrp, sizeof (*mrp));
                                return (ENOTSUP);
                        }
                        /*
                         * Additionally we also need to inherit any
                         * rings property from the MAC.
                         */
                        mac_get_resources((mac_handle_t)mip, mrp);
                        if (mrp->mrp_mask & MRP_RX_RINGS) {
                                vmrp->mrp_mask |= MRP_RX_RINGS;
                                vmrp->mrp_nrxrings = mrp->mrp_nrxrings;
                        }
                        if (mrp->mrp_mask & MRP_TX_RINGS) {
                                vmrp->mrp_mask |= MRP_TX_RINGS;
                                vmrp->mrp_ntxrings = mrp->mrp_ntxrings;
                        }
                }
                bcopy(MCIP_RESOURCE_PROPS(mcip), mrp, sizeof (*mrp));
        }

        muip = kmem_zalloc(sizeof (mac_unicast_impl_t), KM_SLEEP);
        muip->mui_vid = vid;

        if (is_primary || is_vnic_primary) {
                mac_addr = mip->mi_addr;
        } else {

                /*
                 * Verify the validity of the specified MAC addresses value.
                 */
                if (!mac_unicst_verify((mac_handle_t)mip, mac_addr, mac_len)) {
                        *diag = MAC_DIAG_MACADDR_INVALID;
                        err = EINVAL;
                        goto bail_out;
                }

                /*
                 * Make sure that the specified MAC address is different
                 * than the unicast MAC address of the underlying NIC.
                 */
                if (check_dups && bcmp(mip->mi_addr, mac_addr, mac_len) == 0) {
                        *diag = MAC_DIAG_MACADDR_NIC;
                        err = EINVAL;
                        goto bail_out;
                }
        }

        /*
         * Set the flags here so that if this is a passive client, we
         * can return  and set it when we call mac_client_datapath_setup
         * when this becomes the active client. If we defer to using these
         * flags to mac_client_datapath_setup, then for a passive client,
         * we'd have to store the flags somewhere (probably fe_flags)
         * and then use it.
         */
        if (!MCIP_DATAPATH_SETUP(mcip)) {
                if (is_unicast_hw) {
                        /*
                         * The client requires a hardware MAC address slot
                         * for that unicast address. Since we support only
                         * one unicast MAC address per client, flag the
                         * MAC client itself.
                         */
                        mcip->mci_state_flags |= MCIS_UNICAST_HW;
                }

                /* Check for VLAN flags, if present */
                if ((flags & MAC_UNICAST_TAG_DISABLE) != 0)
                        mcip->mci_state_flags |= MCIS_TAG_DISABLE;

                if ((flags & MAC_UNICAST_STRIP_DISABLE) != 0)
                        mcip->mci_state_flags |= MCIS_STRIP_DISABLE;

                if ((flags & MAC_UNICAST_DISABLE_TX_VID_CHECK) != 0)
                        mcip->mci_state_flags |= MCIS_DISABLE_TX_VID_CHECK;
        } else {
                /*
                 * Assert that the specified flags are consistent with the
                 * flags specified by previous calls to mac_unicast_add().
                 */
                ASSERT(((flags & MAC_UNICAST_TAG_DISABLE) != 0 &&
                    (mcip->mci_state_flags & MCIS_TAG_DISABLE) != 0) ||
                    ((flags & MAC_UNICAST_TAG_DISABLE) == 0 &&
                    (mcip->mci_state_flags & MCIS_TAG_DISABLE) == 0));

                ASSERT(((flags & MAC_UNICAST_STRIP_DISABLE) != 0 &&
                    (mcip->mci_state_flags & MCIS_STRIP_DISABLE) != 0) ||
                    ((flags & MAC_UNICAST_STRIP_DISABLE) == 0 &&
                    (mcip->mci_state_flags & MCIS_STRIP_DISABLE) == 0));

                ASSERT(((flags & MAC_UNICAST_DISABLE_TX_VID_CHECK) != 0 &&
                    (mcip->mci_state_flags & MCIS_DISABLE_TX_VID_CHECK) != 0) ||
                    ((flags & MAC_UNICAST_DISABLE_TX_VID_CHECK) == 0 &&
                    (mcip->mci_state_flags & MCIS_DISABLE_TX_VID_CHECK) == 0));

                /*
                 * Make sure the client is consistent about its requests
                 * for MAC addresses. I.e. all requests from the clients
                 * must have the MAC_UNICAST_HW flag set or clear.
                 */
                if ((mcip->mci_state_flags & MCIS_UNICAST_HW) != 0 &&
                    !is_unicast_hw ||
                    (mcip->mci_state_flags & MCIS_UNICAST_HW) == 0 &&
                    is_unicast_hw) {
                        err = EINVAL;
                        goto bail_out;
                }
        }
        /*
         * Make sure the MAC address is not already used by
         * another MAC client defined on top of the same
         * underlying NIC. Unless we have MAC_CLIENT_FLAGS_MULTI_PRIMARY
         * set when we allow a passive client to be present which will
         * be activated when the currently active client goes away - this
         * works only with primary addresses.
         */
        if ((check_dups || is_primary || is_vnic_primary) &&
            mac_addr_in_use(mip, mac_addr, vid)) {
                /*
                 * Must have set the multiple primary address flag when
                 * we did a mac_client_open AND this should be a primary
                 * MAC client AND there should not already be a passive
                 * primary. If all is true then we let this succeed
                 * even if the address is a dup.
                 */
                if ((mcip->mci_flags & MAC_CLIENT_FLAGS_MULTI_PRIMARY) == 0 ||
                    (mcip->mci_flags & MAC_CLIENT_FLAGS_PRIMARY) == 0 ||
                    mac_get_passive_primary_client(mip) != NULL) {
                        *diag = MAC_DIAG_MACADDR_INUSE;
                        err = EEXIST;
                        goto bail_out;
                }
                ASSERT((mcip->mci_flags &
                    MAC_CLIENT_FLAGS_PASSIVE_PRIMARY) == 0);
                mcip->mci_flags |= MAC_CLIENT_FLAGS_PASSIVE_PRIMARY;
                kmem_free(mrp, sizeof (*mrp));

                /*
                 * Stash the unicast address handle, we will use it when
                 * we set up the passive client.
                 */
                mcip->mci_p_unicast_list = muip;
                *mah = (mac_unicast_handle_t)muip;
                return (0);
        }

        err = mac_client_datapath_setup(mcip, vid, mac_addr, mrp,
            is_primary || is_vnic_primary, muip);
        if (err != 0)
                goto bail_out;

        kmem_free(mrp, sizeof (*mrp));
        *mah = (mac_unicast_handle_t)muip;
        return (0);

bail_out:
        if (fastpath_disabled)
                mac_fastpath_enable((mac_handle_t)mip);
        if (mcip->mci_state_flags & MCIS_EXCLUSIVE) {
                mip->mi_state_flags &= ~MIS_EXCLUSIVE;
                if (mip->mi_state_flags & MIS_LEGACY) {
                        mip->mi_capab_legacy.ml_active_clear(
                            mip->mi_driver);
                }
        }
        kmem_free(mrp, sizeof (*mrp));
        kmem_free(muip, sizeof (mac_unicast_impl_t));
        return (err);
}

/*
 * Wrapper function to mac_unicast_add when we want to have the same mac
 * client open for two instances, one that is currently active and another
 * that will become active when the current one is removed. In this case
 * mac_unicast_add will return EGAIN and we will save the rx function and
 * arg which will be used when we activate the passive client in
 * mac_unicast_remove.
 */
int
mac_unicast_add_set_rx(mac_client_handle_t mch, uint8_t *mac_addr,
    uint16_t flags, mac_unicast_handle_t *mah,  uint16_t vid, mac_diag_t *diag,
    mac_rx_t rx_fn, void *arg)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        uint_t                  err;

        err = mac_unicast_add(mch, mac_addr, flags, mah, vid, diag);
        if (err != 0 && err != EAGAIN)
                return (err);
        if (err == EAGAIN) {
                if (rx_fn != NULL) {
                        mcip->mci_rx_p_fn = rx_fn;
                        mcip->mci_rx_p_arg = arg;
                }
                return (0);
        }
        if (rx_fn != NULL)
                mac_rx_set(mch, rx_fn, arg);
        return (err);
}

int
mac_unicast_add(mac_client_handle_t mch, uint8_t *mac_addr, uint16_t flags,
    mac_unicast_handle_t *mah, uint16_t vid, mac_diag_t *diag)
{
        mac_impl_t *mip = ((mac_client_impl_t *)mch)->mci_mip;
        uint_t err;

        i_mac_perim_enter(mip);
        err = i_mac_unicast_add(mch, mac_addr, flags, mah, vid, diag);
        i_mac_perim_exit(mip);

        return (err);
}

static void
mac_client_datapath_teardown(mac_client_handle_t mch, mac_unicast_impl_t *muip,
    flow_entry_t *flent)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        boolean_t               no_unicast;

        /*
         * If we have not added a unicast address for this MAC client, just
         * teardown the datapath.
         */
        no_unicast = mcip->mci_state_flags & MCIS_NO_UNICAST_ADDR;

        if (!no_unicast) {
                /*
                 * We would have initialized subflows etc. only if we brought
                 * up the primary client and set the unicast unicast address
                 * etc. Deactivate the flows. The flow entry will be removed
                 * from the active flow tables, and the associated SRS,
                 * softrings etc will be deleted. But the flow entry itself
                 * won't be destroyed, instead it will continue to be archived
                 * off the  the global flow hash list, for a possible future
                 * activation when say IP is plumbed again.
                 */
                mac_link_release_flows(mch);
        }
        mip->mi_nactiveclients--;
        mac_update_single_active_client(mip);

        /* Tear down the data path */
        mac_datapath_teardown(mcip, mcip->mci_flent, SRST_LINK);

        /*
         * Prevent any future access to the flow entry through the mci_flent
         * pointer by setting the mci_flent to NULL. Access to mci_flent in
         * mac_bcast_send is also under mi_rw_lock.
         */
        rw_enter(&mip->mi_rw_lock, RW_WRITER);
        flent = mcip->mci_flent;
        mac_client_remove_flow_from_list(mcip, flent);

        if (mcip->mci_state_flags & MCIS_DESC_LOGGED)
                mcip->mci_state_flags &= ~MCIS_DESC_LOGGED;

        /*
         * This is the last unicast address being removed and there shouldn't
         * be any outbound data threads at this point coming down from mac
         * clients. We have waited for the data threads to finish before
         * starting dld_str_detach. Non-data threads must access TX SRS
         * under mi_rw_lock.
         */
        rw_exit(&mip->mi_rw_lock);

        /*
         * Don't use FLOW_MARK with FE_MC_NO_DATAPATH, as the flow might
         * contain other flags, such as FE_CONDEMNED, which we need to
         * cleared. We don't call mac_flow_cleanup() for this unicast
         * flow as we have a already cleaned up SRSs etc. (via the teadown
         * path). We just clear the stats and reset the initial callback
         * function, the rest will be set when we call mac_flow_create,
         * if at all.
         */
        mutex_enter(&flent->fe_lock);
        ASSERT(flent->fe_refcnt == 1 && flent->fe_mbg == NULL &&
            flent->fe_tx_srs == NULL && flent->fe_rx_srs_cnt == 0);
        flent->fe_flags = FE_MC_NO_DATAPATH;
        flow_stat_destroy(flent);
        mac_misc_stat_delete(flent);

        /* Initialize the receiver function to a safe routine */
        flent->fe_cb_fn = (flow_fn_t)mac_pkt_drop;
        flent->fe_cb_arg1 = NULL;
        flent->fe_cb_arg2 = NULL;

        flent->fe_index = -1;
        mutex_exit(&flent->fe_lock);

        if (mip->mi_type->mt_brdcst_addr != NULL) {
                ASSERT(muip != NULL || no_unicast);
                mac_bcast_delete(mcip, mip->mi_type->mt_brdcst_addr,
                    muip != NULL ? muip->mui_vid : VLAN_ID_NONE);
        }

        if (mip->mi_nactiveclients == 1) {
                mac_capab_update((mac_handle_t)mip);
                mac_virtual_link_update(mip);
        }

        if (mcip->mci_state_flags & MCIS_EXCLUSIVE) {
                mip->mi_state_flags &= ~MIS_EXCLUSIVE;

                if (mip->mi_state_flags & MIS_LEGACY)
                        mip->mi_capab_legacy.ml_active_clear(mip->mi_driver);
        }

        mcip->mci_state_flags &= ~MCIS_UNICAST_HW;

        if (mcip->mci_state_flags & MCIS_TAG_DISABLE)
                mcip->mci_state_flags &= ~MCIS_TAG_DISABLE;

        if (mcip->mci_state_flags & MCIS_STRIP_DISABLE)
                mcip->mci_state_flags &= ~MCIS_STRIP_DISABLE;

        if (mcip->mci_state_flags & MCIS_DISABLE_TX_VID_CHECK)
                mcip->mci_state_flags &= ~MCIS_DISABLE_TX_VID_CHECK;

        if (muip != NULL)
                kmem_free(muip, sizeof (mac_unicast_impl_t));
        mac_protect_cancel_timer(mcip);
        mac_protect_flush_dhcp(mcip);

        bzero(&mcip->mci_misc_stat, sizeof (mcip->mci_misc_stat));
        /*
         * Disable fastpath if this is a VNIC or a VLAN.
         */
        if (mcip->mci_state_flags & MCIS_IS_VNIC)
                mac_fastpath_enable((mac_handle_t)mip);
        mac_stop((mac_handle_t)mip);
}

/*
 * Remove a MAC address which was previously added by mac_unicast_add().
 */
int
mac_unicast_remove(mac_client_handle_t mch, mac_unicast_handle_t mah)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_unicast_impl_t *muip = (mac_unicast_impl_t *)mah;
        mac_unicast_impl_t *pre;
        mac_impl_t *mip = mcip->mci_mip;
        flow_entry_t            *flent;
        uint16_t mui_vid;

        i_mac_perim_enter(mip);
        if (mcip->mci_flags & MAC_CLIENT_FLAGS_VNIC_PRIMARY) {
                /*
                 * Called made by the upper MAC client of a VNIC.
                 * There's nothing much to do, the unicast address will
                 * be removed by the VNIC driver when the VNIC is deleted,
                 * but let's ensure that all our transmit is done before
                 * the client does a mac_client_stop lest it trigger an
                 * assert in the driver.
                 */
                ASSERT(muip->mui_vid == 0);

                mac_tx_client_flush(mcip);

                if ((mcip->mci_flags & MAC_CLIENT_FLAGS_PASSIVE_PRIMARY) != 0) {
                        mcip->mci_flags &= ~MAC_CLIENT_FLAGS_PASSIVE_PRIMARY;
                        if (mcip->mci_rx_p_fn != NULL) {
                                mac_rx_set(mch, mcip->mci_rx_p_fn,
                                    mcip->mci_rx_p_arg);
                                mcip->mci_rx_p_fn = NULL;
                                mcip->mci_rx_p_arg = NULL;
                        }
                        kmem_free(muip, sizeof (mac_unicast_impl_t));
                        i_mac_perim_exit(mip);
                        return (0);
                }
                mcip->mci_flags &= ~MAC_CLIENT_FLAGS_VNIC_PRIMARY;

                if (mcip->mci_state_flags & MCIS_TAG_DISABLE)
                        mcip->mci_state_flags &= ~MCIS_TAG_DISABLE;

                if (mcip->mci_state_flags & MCIS_STRIP_DISABLE)
                        mcip->mci_state_flags &= ~MCIS_STRIP_DISABLE;

                if (mcip->mci_state_flags & MCIS_DISABLE_TX_VID_CHECK)
                        mcip->mci_state_flags &= ~MCIS_DISABLE_TX_VID_CHECK;

                kmem_free(muip, sizeof (mac_unicast_impl_t));
                i_mac_perim_exit(mip);
                return (0);
        }

        ASSERT(muip != NULL);

        /*
         * We are removing a passive client, we haven't setup the datapath
         * for this yet, so nothing much to do.
         */
        if ((mcip->mci_flags & MAC_CLIENT_FLAGS_PASSIVE_PRIMARY) != 0) {

                ASSERT((mcip->mci_flent->fe_flags & FE_MC_NO_DATAPATH) != 0);
                ASSERT(mcip->mci_p_unicast_list == muip);

                mcip->mci_flags &= ~MAC_CLIENT_FLAGS_PASSIVE_PRIMARY;

                mcip->mci_p_unicast_list = NULL;
                mcip->mci_rx_p_fn = NULL;
                mcip->mci_rx_p_arg = NULL;

                mcip->mci_state_flags &= ~MCIS_UNICAST_HW;

                if (mcip->mci_state_flags & MCIS_TAG_DISABLE)
                        mcip->mci_state_flags &= ~MCIS_TAG_DISABLE;

                if (mcip->mci_state_flags & MCIS_STRIP_DISABLE)
                        mcip->mci_state_flags &= ~MCIS_STRIP_DISABLE;

                if (mcip->mci_state_flags & MCIS_DISABLE_TX_VID_CHECK)
                        mcip->mci_state_flags &= ~MCIS_DISABLE_TX_VID_CHECK;

                kmem_free(muip, sizeof (mac_unicast_impl_t));
                i_mac_perim_exit(mip);
                return (0);
        }
        /*
         * Remove the VID from the list of client's VIDs.
         */
        pre = mcip->mci_unicast_list;
        if (muip == pre) {
                mcip->mci_unicast_list = muip->mui_next;
        } else {
                while ((pre->mui_next != NULL) && (pre->mui_next != muip))
                        pre = pre->mui_next;
                ASSERT(pre->mui_next == muip);
                rw_enter(&mcip->mci_rw_lock, RW_WRITER);
                pre->mui_next = muip->mui_next;
                rw_exit(&mcip->mci_rw_lock);
        }

        if (!mac_client_single_rcvr(mcip)) {
                /*
                 * This MAC client is shared by more than one unicast
                 * addresses, so we will just remove the flent
                 * corresponding to the address being removed. We don't invoke
                 * mac_rx_classify_flow_rem() since the additional flow is
                 * not associated with its own separate set of SRS and rings,
                 * and these constructs are still needed for the remaining
                 * flows.
                 */
                flent = mac_client_get_flow(mcip, muip);
                ASSERT(flent != NULL);

                /*
                 * The first one is disappearing, need to make sure
                 * we replace it with another from the list of
                 * shared clients.
                 */
                if (flent == mcip->mci_flent)
                        flent = mac_client_swap_mciflent(mcip);
                mac_client_remove_flow_from_list(mcip, flent);
                mac_flow_remove(mip->mi_flow_tab, flent, B_FALSE);
                mac_flow_wait(flent, FLOW_DRIVER_UPCALL);

                /*
                 * The multicast groups that were added by the client so
                 * far must be removed from the brodcast domain corresponding
                 * to the VID being removed.
                 */
                mac_client_bcast_refresh(mcip, mac_client_update_mcast,
                    (void *)flent, B_FALSE);

                if (mip->mi_type->mt_brdcst_addr != NULL) {
                        mac_bcast_delete(mcip, mip->mi_type->mt_brdcst_addr,
                            muip->mui_vid);
                }

                FLOW_FINAL_REFRELE(flent);
                ASSERT(!(mcip->mci_state_flags & MCIS_EXCLUSIVE));
                /*
                 * Enable fastpath if this is a VNIC or a VLAN.
                 */
                if (mcip->mci_state_flags & MCIS_IS_VNIC)
                        mac_fastpath_enable((mac_handle_t)mip);
                mac_stop((mac_handle_t)mip);
                i_mac_perim_exit(mip);
                return (0);
        }

        mui_vid = muip->mui_vid;
        mac_client_datapath_teardown(mch, muip, flent);

        if ((mcip->mci_flags & MAC_CLIENT_FLAGS_PRIMARY) && mui_vid == 0) {
                mcip->mci_flags &= ~MAC_CLIENT_FLAGS_PRIMARY;
        } else {
                i_mac_perim_exit(mip);
                return (0);
        }

        /*
         * If we are removing the primary, check if we have a passive primary
         * client that we need to activate now.
         */
        mcip = mac_get_passive_primary_client(mip);
        if (mcip != NULL) {
                mac_resource_props_t    *mrp;
                mac_unicast_impl_t      *muip;

                mcip->mci_flags &= ~MAC_CLIENT_FLAGS_PASSIVE_PRIMARY;
                mrp = kmem_zalloc(sizeof (*mrp), KM_SLEEP);

                /*
                 * Apply the property cached in the mac_impl_t to the
                 * primary mac client.
                 */
                mac_get_resources((mac_handle_t)mip, mrp);
                (void) mac_client_set_resources(mch, mrp);
                ASSERT(mcip->mci_p_unicast_list != NULL);
                muip = mcip->mci_p_unicast_list;
                mcip->mci_p_unicast_list = NULL;
                if (mac_client_datapath_setup(mcip, VLAN_ID_NONE,
                    mip->mi_addr, mrp, B_TRUE, muip) == 0) {
                        if (mcip->mci_rx_p_fn != NULL) {
                                mac_rx_set(mch, mcip->mci_rx_p_fn,
                                    mcip->mci_rx_p_arg);
                                mcip->mci_rx_p_fn = NULL;
                                mcip->mci_rx_p_arg = NULL;
                        }
                } else {
                        kmem_free(muip, sizeof (mac_unicast_impl_t));
                }
                kmem_free(mrp, sizeof (*mrp));
        }
        i_mac_perim_exit(mip);
        return (0);
}

/*
 * Multicast add function invoked by MAC clients.
 */
int
mac_multicast_add(mac_client_handle_t mch, const uint8_t *addr)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        flow_entry_t            *flent = mcip->mci_flent_list;
        flow_entry_t            *prev_fe = NULL;
        uint16_t                vid;
        int                     err = 0;

        /* Verify the address is a valid multicast address */
        if ((err = mip->mi_type->mt_ops.mtops_multicst_verify(addr,
            mip->mi_pdata)) != 0)
                return (err);

        i_mac_perim_enter(mip);
        while (flent != NULL) {
                vid = i_mac_flow_vid(flent);

                err = mac_bcast_add((mac_client_impl_t *)mch, addr, vid,
                    MAC_ADDRTYPE_MULTICAST);
                if (err != 0)
                        break;
                prev_fe = flent;
                flent = flent->fe_client_next;
        }

        /*
         * If we failed adding, then undo all, rather than partial
         * success.
         */
        if (flent != NULL && prev_fe != NULL) {
                flent = mcip->mci_flent_list;
                while (flent != prev_fe->fe_client_next) {
                        vid = i_mac_flow_vid(flent);
                        mac_bcast_delete((mac_client_impl_t *)mch, addr, vid);
                        flent = flent->fe_client_next;
                }
        }
        i_mac_perim_exit(mip);
        return (err);
}

/*
 * Multicast delete function invoked by MAC clients.
 */
void
mac_multicast_remove(mac_client_handle_t mch, const uint8_t *addr)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        flow_entry_t            *flent;
        uint16_t                vid;

        i_mac_perim_enter(mip);
        for (flent = mcip->mci_flent_list; flent != NULL;
            flent = flent->fe_client_next) {
                vid = i_mac_flow_vid(flent);
                mac_bcast_delete((mac_client_impl_t *)mch, addr, vid);
        }
        i_mac_perim_exit(mip);
}

/*
 * When a MAC client desires to capture packets on an interface,
 * it registers a promiscuous call back with mac_promisc_add().
 * There are three types of promiscuous callbacks:
 *
 * * MAC_CLIENT_PROMISC_ALL
 *   Captures all packets sent and received by the MAC client,
 *   the physical interface, as well as all other MAC clients
 *   defined on top of the same MAC.
 *
 * * MAC_CLIENT_PROMISC_FILTERED
 *   Captures all packets sent and received by the MAC client,
 *   plus all multicast traffic sent and received by the phyisical
 *   interface and the other MAC clients.
 *
 * * MAC_CLIENT_PROMISC_MULTI
 *   Captures all broadcast and multicast packets sent and
 *   received by the MAC clients as well as the physical interface.
 *
 * In all cases, the underlying MAC is put in promiscuous mode.
 */
int
mac_promisc_add(mac_client_handle_t mch, mac_client_promisc_type_t type,
    mac_rx_t fn, void *arg, mac_promisc_handle_t *mphp, uint16_t flags)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;
        mac_promisc_impl_t *mpip;
        mac_cb_info_t   *mcbi;
        int rc;

        i_mac_perim_enter(mip);

        if ((rc = mac_start((mac_handle_t)mip)) != 0) {
                i_mac_perim_exit(mip);
                return (rc);
        }

        if ((mcip->mci_state_flags & MCIS_IS_VNIC) &&
            type == MAC_CLIENT_PROMISC_ALL) {
                /*
                 * The function is being invoked by the upper MAC client
                 * of a VNIC. The VNIC should only see the traffic
                 * it is entitled to.
                 */
                type = MAC_CLIENT_PROMISC_FILTERED;
        }


        /*
         * Turn on promiscuous mode for the underlying NIC.
         * This is needed even for filtered callbacks which
         * expect to receive all multicast traffic on the wire.
         *
         * Physical promiscuous mode should not be turned on if
         * MAC_PROMISC_FLAGS_NO_PHYS is set.
         */
        if ((flags & MAC_PROMISC_FLAGS_NO_PHYS) == 0) {
                if ((rc = i_mac_promisc_set(mip, B_TRUE)) != 0) {
                        mac_stop((mac_handle_t)mip);
                        i_mac_perim_exit(mip);
                        return (rc);
                }
        }

        mpip = kmem_cache_alloc(mac_promisc_impl_cache, KM_SLEEP);

        mpip->mpi_type = type;
        mpip->mpi_fn = fn;
        mpip->mpi_arg = arg;
        mpip->mpi_mcip = mcip;
        mpip->mpi_no_tx_loop = ((flags & MAC_PROMISC_FLAGS_NO_TX_LOOP) != 0);
        mpip->mpi_no_phys = ((flags & MAC_PROMISC_FLAGS_NO_PHYS) != 0);
        mpip->mpi_strip_vlan_tag =
            ((flags & MAC_PROMISC_FLAGS_VLAN_TAG_STRIP) != 0);
        mpip->mpi_no_copy = ((flags & MAC_PROMISC_FLAGS_NO_COPY) != 0);

        mcbi = &mip->mi_promisc_cb_info;
        mutex_enter(mcbi->mcbi_lockp);

        mac_callback_add(&mip->mi_promisc_cb_info, &mcip->mci_promisc_list,
            &mpip->mpi_mci_link);
        mac_callback_add(&mip->mi_promisc_cb_info, &mip->mi_promisc_list,
            &mpip->mpi_mi_link);

        mutex_exit(mcbi->mcbi_lockp);

        *mphp = (mac_promisc_handle_t)mpip;

        if (mcip->mci_state_flags & MCIS_IS_VNIC) {
                mac_impl_t *umip = mcip->mci_upper_mip;

                ASSERT(umip != NULL);
                mac_vnic_secondary_update(umip);
        }

        i_mac_perim_exit(mip);

        return (0);
}

/*
 * Remove a multicast address previously aded through mac_promisc_add().
 */
void
mac_promisc_remove(mac_promisc_handle_t mph)
{
        mac_promisc_impl_t *mpip = (mac_promisc_impl_t *)mph;
        mac_client_impl_t *mcip = mpip->mpi_mcip;
        mac_impl_t *mip = mcip->mci_mip;
        mac_cb_info_t *mcbi;
        int rv;

        i_mac_perim_enter(mip);

        /*
         * Even if the device can't be reset into normal mode, we still
         * need to clear the client promisc callbacks. The client may want
         * to close the mac end point and we can't have stale callbacks.
         */
        if (!(mpip->mpi_no_phys)) {
                if ((rv = i_mac_promisc_set(mip, B_FALSE)) != 0) {
                        cmn_err(CE_WARN, "%s: failed to switch OFF promiscuous"
                            " mode because of error 0x%x", mip->mi_name, rv);
                }
        }
        mcbi = &mip->mi_promisc_cb_info;
        mutex_enter(mcbi->mcbi_lockp);
        if (mac_callback_remove(mcbi, &mip->mi_promisc_list,
            &mpip->mpi_mi_link)) {
                VERIFY(mac_callback_remove(&mip->mi_promisc_cb_info,
                    &mcip->mci_promisc_list, &mpip->mpi_mci_link));
                kmem_cache_free(mac_promisc_impl_cache, mpip);
        } else {
                mac_callback_remove_wait(&mip->mi_promisc_cb_info);
        }

        if (mcip->mci_state_flags & MCIS_IS_VNIC) {
                mac_impl_t *umip = mcip->mci_upper_mip;

                ASSERT(umip != NULL);
                mac_vnic_secondary_update(umip);
        }

        mutex_exit(mcbi->mcbi_lockp);
        mac_stop((mac_handle_t)mip);

        i_mac_perim_exit(mip);
}

/*
 * Reference count the number of active Tx threads. MCI_TX_QUIESCE indicates
 * that a control operation wants to quiesce the Tx data flow in which case
 * we return an error. Holding any of the per cpu locks ensures that the
 * mci_tx_flag won't change.
 *
 * 'CPU' must be accessed just once and used to compute the index into the
 * percpu array, and that index must be used for the entire duration of the
 * packet send operation. Note that the thread may be preempted and run on
 * another cpu any time and so we can't use 'CPU' more than once for the
 * operation.
 */
#define MAC_TX_TRY_HOLD(mcip, mytx, error)                              \
{                                                                       \
        (error) = 0;                                                    \
        (mytx) = &(mcip)->mci_tx_pcpu[CPU->cpu_seqid & mac_tx_percpu_cnt]; \
        mutex_enter(&(mytx)->pcpu_tx_lock);                             \
        if (!((mcip)->mci_tx_flag & MCI_TX_QUIESCE)) {                  \
                (mytx)->pcpu_tx_refcnt++;                               \
        } else {                                                        \
                (error) = -1;                                           \
        }                                                               \
        mutex_exit(&(mytx)->pcpu_tx_lock);                              \
}

/*
 * Release the reference. If needed, signal any control operation waiting
 * for Tx quiescence. The wait and signal are always done using the
 * mci_tx_pcpu[0]'s lock
 */
#define MAC_TX_RELE(mcip, mytx) {                                       \
        mutex_enter(&(mytx)->pcpu_tx_lock);                             \
        if (--(mytx)->pcpu_tx_refcnt == 0 &&                            \
            (mcip)->mci_tx_flag & MCI_TX_QUIESCE) {                     \
                mutex_exit(&(mytx)->pcpu_tx_lock);                      \
                mutex_enter(&(mcip)->mci_tx_pcpu[0].pcpu_tx_lock);      \
                cv_signal(&(mcip)->mci_tx_cv);                          \
                mutex_exit(&(mcip)->mci_tx_pcpu[0].pcpu_tx_lock);       \
        } else {                                                        \
                mutex_exit(&(mytx)->pcpu_tx_lock);                      \
        }                                                               \
}

/*
 * Send function invoked by MAC clients.
 */
mac_tx_cookie_t
mac_tx(mac_client_handle_t mch, mblk_t *mp_chain, uintptr_t hint,
    uint16_t flag, mblk_t **ret_mp)
{
        mac_tx_cookie_t         cookie = NULL;
        int                     error;
        mac_tx_percpu_t         *mytx;
        mac_soft_ring_set_t     *srs;
        flow_entry_t            *flent;
        boolean_t               is_subflow = B_FALSE;
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;
        mac_srs_tx_t            *srs_tx;

        /*
         * Check whether the active Tx threads count is bumped already.
         */
        if (!(flag & MAC_TX_NO_HOLD)) {
                MAC_TX_TRY_HOLD(mcip, mytx, error);
                if (error != 0) {
                        freemsgchain(mp_chain);
                        return (NULL);
                }
        }

        /*
         * If mac protection is enabled, only the permissible packets will be
         * returned by mac_protect_check().
         */
        if ((mcip->mci_flent->
            fe_resource_props.mrp_mask & MRP_PROTECT) != 0 &&
            (mp_chain = mac_protect_check(mch, mp_chain)) == NULL)
                goto done;

        if (mcip->mci_subflow_tab != NULL &&
            mcip->mci_subflow_tab->ft_flow_count > 0 &&
            mac_flow_lookup(mcip->mci_subflow_tab, mp_chain,
            FLOW_OUTBOUND, &flent) == 0) {
                /*
                 * The main assumption here is that if in the event
                 * we get a chain, all the packets will be classified
                 * to the same Flow/SRS. If this changes for any
                 * reason, the following logic should change as well.
                 * I suppose the fanout_hint also assumes this .
                 */
                ASSERT(flent != NULL);
                is_subflow = B_TRUE;
        } else {
                flent = mcip->mci_flent;
        }

        srs = flent->fe_tx_srs;
        /*
         * This is to avoid panics with PF_PACKET that can call mac_tx()
         * against an interface that is not capable of sending. A rewrite
         * of the mac datapath is required to remove this limitation.
         */
        if (srs == NULL) {
                freemsgchain(mp_chain);
                goto done;
        }

        srs_tx = &srs->srs_tx;
        if (srs_tx->st_mode == SRS_TX_DEFAULT &&
            (srs->srs_state & SRS_ENQUEUED) == 0 &&
            mip->mi_nactiveclients == 1 && mp_chain->b_next == NULL) {
                uint64_t        obytes;

                /*
                 * Since dls always opens the underlying MAC, nclients equals
                 * to 1 means that the only active client is dls itself acting
                 * as a primary client of the MAC instance. Since dls will not
                 * send tagged packets in that case, and dls is trusted to send
                 * packets for its allowed VLAN(s), the VLAN tag insertion and
                 * check is required only if nclients is greater than 1.
                 */
                if (mip->mi_nclients > 1) {
                        if (MAC_VID_CHECK_NEEDED(mcip)) {
                                int     err = 0;

                                MAC_VID_CHECK(mcip, mp_chain, err);
                                if (err != 0) {
                                        freemsg(mp_chain);
                                        mcip->mci_misc_stat.mms_txerrors++;
                                        goto done;
                                }
                        }
                        if (MAC_TAG_NEEDED(mcip)) {
                                mp_chain = mac_add_vlan_tag(mp_chain, 0,
                                    mac_client_vid(mch));
                                if (mp_chain == NULL) {
                                        mcip->mci_misc_stat.mms_txerrors++;
                                        goto done;
                                }
                        }
                }

                obytes = (mp_chain->b_cont == NULL ? MBLKL(mp_chain) :
                    msgdsize(mp_chain));

                MAC_TX(mip, srs_tx->st_arg2, mp_chain, mcip);
                if (mp_chain == NULL) {
                        cookie = NULL;
                        SRS_TX_STAT_UPDATE(srs, opackets, 1);
                        SRS_TX_STAT_UPDATE(srs, obytes, obytes);
                } else {
                        mutex_enter(&srs->srs_lock);
                        cookie = mac_tx_srs_no_desc(srs, mp_chain,
                            flag, ret_mp);
                        mutex_exit(&srs->srs_lock);
                }
        } else {
                cookie = srs_tx->st_func(srs, mp_chain, hint, flag, ret_mp);
        }

done:
        if (is_subflow)
                FLOW_REFRELE(flent);

        if (!(flag & MAC_TX_NO_HOLD))
                MAC_TX_RELE(mcip, mytx);

        return (cookie);
}

/*
 * mac_tx_is_blocked
 *
 * Given a cookie, it returns if the ring identified by the cookie is
 * flow-controlled or not. If NULL is passed in place of a cookie,
 * then it finds out if any of the underlying rings belonging to the
 * SRS is flow controlled or not and returns that status.
 */
/* ARGSUSED */
boolean_t
mac_tx_is_flow_blocked(mac_client_handle_t mch, mac_tx_cookie_t cookie)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_soft_ring_set_t *mac_srs;
        mac_soft_ring_t *sringp;
        boolean_t blocked = B_FALSE;
        mac_tx_percpu_t *mytx;
        int err;
        int i;

        /*
         * Bump the reference count so that mac_srs won't be deleted.
         * If the client is currently quiesced and we failed to bump
         * the reference, return B_TRUE so that flow control stays
         * as enabled.
         *
         * Flow control will then be disabled once the client is no
         * longer quiesced.
         */
        MAC_TX_TRY_HOLD(mcip, mytx, err);
        if (err != 0)
                return (B_TRUE);

        if ((mac_srs = MCIP_TX_SRS(mcip)) == NULL) {
                MAC_TX_RELE(mcip, mytx);
                return (B_FALSE);
        }

        mutex_enter(&mac_srs->srs_lock);
        /*
         * Only in the case of TX_FANOUT and TX_AGGR, the underlying
         * softring (s_ring_state) will have the HIWAT set. This is
         * the multiple Tx ring flow control case. For all other
         * case, SRS (srs_state) will store the condition.
         */
        if (mac_srs->srs_tx.st_mode == SRS_TX_FANOUT ||
            mac_srs->srs_tx.st_mode == SRS_TX_AGGR) {
                if (cookie != NULL) {
                        sringp = (mac_soft_ring_t *)cookie;
                        mutex_enter(&sringp->s_ring_lock);
                        if (sringp->s_ring_state & S_RING_TX_HIWAT)
                                blocked = B_TRUE;
                        mutex_exit(&sringp->s_ring_lock);
                } else {
                        for (i = 0; i < mac_srs->srs_tx_ring_count; i++) {
                                sringp = mac_srs->srs_tx_soft_rings[i];
                                mutex_enter(&sringp->s_ring_lock);
                                if (sringp->s_ring_state & S_RING_TX_HIWAT) {
                                        blocked = B_TRUE;
                                        mutex_exit(&sringp->s_ring_lock);
                                        break;
                                }
                                mutex_exit(&sringp->s_ring_lock);
                        }
                }
        } else {
                blocked = (mac_srs->srs_state & SRS_TX_HIWAT);
        }
        mutex_exit(&mac_srs->srs_lock);
        MAC_TX_RELE(mcip, mytx);
        return (blocked);
}

/*
 * Check if the MAC client is the primary MAC client.
 */
boolean_t
mac_is_primary_client(mac_client_impl_t *mcip)
{
        return (mcip->mci_flags & MAC_CLIENT_FLAGS_PRIMARY);
}

void
mac_ioctl(mac_handle_t mh, queue_t *wq, mblk_t *bp)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        int cmd = ((struct iocblk *)bp->b_rptr)->ioc_cmd;

        if ((cmd == ND_GET && (mip->mi_callbacks->mc_callbacks & MC_GETPROP)) ||
            (cmd == ND_SET && (mip->mi_callbacks->mc_callbacks & MC_SETPROP))) {
                /*
                 * If ndd props were registered, call them.
                 * Note that ndd ioctls are Obsolete
                 */
                mac_ndd_ioctl(mip, wq, bp);
                return;
        }

        /*
         * Call the driver to handle the ioctl.  The driver may not support
         * any ioctls, in which case we reply with a NAK on its behalf.
         */
        if (mip->mi_callbacks->mc_callbacks & MC_IOCTL)
                mip->mi_ioctl(mip->mi_driver, wq, bp);
        else
                miocnak(wq, bp, 0, EINVAL);
}

/*
 * Return the link state of the specified MAC instance.
 */
link_state_t
mac_link_get(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_linkstate);
}

/*
 * Add a mac client specified notification callback. Please see the comments
 * above mac_callback_add() for general information about mac callback
 * addition/deletion in the presence of mac callback list walkers
 */
mac_notify_handle_t
mac_notify_add(mac_handle_t mh, mac_notify_t notify_fn, void *arg)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_notify_cb_t         *mncb;
        mac_cb_info_t           *mcbi;

        /*
         * Allocate a notify callback structure, fill in the details and
         * use the mac callback list manipulation functions to chain into
         * the list of callbacks.
         */
        mncb = kmem_zalloc(sizeof (mac_notify_cb_t), KM_SLEEP);
        mncb->mncb_fn = notify_fn;
        mncb->mncb_arg = arg;
        mncb->mncb_mip = mip;
        mncb->mncb_link.mcb_objp = mncb;
        mncb->mncb_link.mcb_objsize = sizeof (mac_notify_cb_t);
        mncb->mncb_link.mcb_flags = MCB_NOTIFY_CB_T;

        mcbi = &mip->mi_notify_cb_info;

        i_mac_perim_enter(mip);
        mutex_enter(mcbi->mcbi_lockp);

        mac_callback_add(&mip->mi_notify_cb_info, &mip->mi_notify_cb_list,
            &mncb->mncb_link);

        mutex_exit(mcbi->mcbi_lockp);
        i_mac_perim_exit(mip);
        return ((mac_notify_handle_t)mncb);
}

void
mac_notify_remove_wait(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        mac_cb_info_t   *mcbi = &mip->mi_notify_cb_info;

        mutex_enter(mcbi->mcbi_lockp);
        mac_callback_remove_wait(&mip->mi_notify_cb_info);
        mutex_exit(mcbi->mcbi_lockp);
}

/*
 * Remove a mac client specified notification callback
 */
int
mac_notify_remove(mac_notify_handle_t mnh, boolean_t wait)
{
        mac_notify_cb_t *mncb = (mac_notify_cb_t *)mnh;
        mac_impl_t      *mip = mncb->mncb_mip;
        mac_cb_info_t   *mcbi;
        int             err = 0;

        mcbi = &mip->mi_notify_cb_info;

        i_mac_perim_enter(mip);
        mutex_enter(mcbi->mcbi_lockp);

        ASSERT(mncb->mncb_link.mcb_objp == mncb);
        /*
         * If there aren't any list walkers, the remove would succeed
         * inline, else we wait for the deferred remove to complete
         */
        if (mac_callback_remove(&mip->mi_notify_cb_info,
            &mip->mi_notify_cb_list, &mncb->mncb_link)) {
                kmem_free(mncb, sizeof (mac_notify_cb_t));
        } else {
                err = EBUSY;
        }

        mutex_exit(mcbi->mcbi_lockp);
        i_mac_perim_exit(mip);

        /*
         * If we failed to remove the notification callback and "wait" is set
         * to be B_TRUE, wait for the callback to finish after we exit the
         * mac perimeter.
         */
        if (err != 0 && wait) {
                mac_notify_remove_wait((mac_handle_t)mip);
                return (0);
        }

        return (err);
}

/*
 * Associate resource management callbacks with the specified MAC
 * clients.
 */

void
mac_resource_set_common(mac_client_handle_t mch, mac_resource_add_t add,
    mac_resource_remove_t remove, mac_resource_quiesce_t quiesce,
    mac_resource_restart_t restart, mac_resource_bind_t bind,
    void *arg)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;

        mcip->mci_resource_add = add;
        mcip->mci_resource_remove = remove;
        mcip->mci_resource_quiesce = quiesce;
        mcip->mci_resource_restart = restart;
        mcip->mci_resource_bind = bind;
        mcip->mci_resource_arg = arg;
}

void
mac_resource_set(mac_client_handle_t mch, mac_resource_add_t add, void *arg)
{
        /* update the 'resource_add' callback */
        mac_resource_set_common(mch, add, NULL, NULL, NULL, NULL, arg);
}

/*
 * Sets up the client resources and enable the polling interface over all the
 * SRS's and the soft rings of the client
 */
void
mac_client_poll_enable(mac_client_handle_t mch)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_soft_ring_set_t     *mac_srs;
        flow_entry_t            *flent;
        int                     i;

        flent = mcip->mci_flent;
        ASSERT(flent != NULL);

        mcip->mci_state_flags |= MCIS_CLIENT_POLL_CAPABLE;
        for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                ASSERT(mac_srs->srs_mcip == mcip);
                mac_srs_client_poll_enable(mcip, mac_srs);
        }
}

/*
 * Tears down the client resources and disable the polling interface over all
 * the SRS's and the soft rings of the client
 */
void
mac_client_poll_disable(mac_client_handle_t mch)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_soft_ring_set_t     *mac_srs;
        flow_entry_t            *flent;
        int                     i;

        flent = mcip->mci_flent;
        ASSERT(flent != NULL);

        mcip->mci_state_flags &= ~MCIS_CLIENT_POLL_CAPABLE;
        for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                ASSERT(mac_srs->srs_mcip == mcip);
                mac_srs_client_poll_disable(mcip, mac_srs);
        }
}

/*
 * Associate the CPUs specified by the given property with a MAC client.
 */
int
mac_cpu_set(mac_client_handle_t mch, mac_resource_props_t *mrp)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;
        int err = 0;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        if ((err = mac_validate_props(mcip->mci_state_flags & MCIS_IS_VNIC ?
            mcip->mci_upper_mip : mip, mrp)) != 0) {
                return (err);
        }
        if (MCIP_DATAPATH_SETUP(mcip))
                mac_flow_modify(mip->mi_flow_tab, mcip->mci_flent, mrp);

        mac_update_resources(mrp, MCIP_RESOURCE_PROPS(mcip), B_FALSE);
        return (0);
}

/*
 * Apply the specified properties to the specified MAC client.
 */
int
mac_client_set_resources(mac_client_handle_t mch, mac_resource_props_t *mrp)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;
        int err = 0;

        i_mac_perim_enter(mip);

        if ((mrp->mrp_mask & MRP_MAXBW) || (mrp->mrp_mask & MRP_PRIORITY)) {
                err = mac_resource_ctl_set(mch, mrp);
                if (err != 0)
                        goto done;
        }

        if (mrp->mrp_mask & (MRP_CPUS|MRP_POOL)) {
                err = mac_cpu_set(mch, mrp);
                if (err != 0)
                        goto done;
        }

        if (mrp->mrp_mask & MRP_PROTECT) {
                err = mac_protect_set(mch, mrp);
                if (err != 0)
                        goto done;
        }

        if ((mrp->mrp_mask & MRP_RX_RINGS) || (mrp->mrp_mask & MRP_TX_RINGS))
                err = mac_resource_ctl_set(mch, mrp);

done:
        i_mac_perim_exit(mip);
        return (err);
}

/*
 * Return the properties currently associated with the specified MAC client.
 */
void
mac_client_get_resources(mac_client_handle_t mch, mac_resource_props_t *mrp)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_resource_props_t    *mcip_mrp = MCIP_RESOURCE_PROPS(mcip);

        bcopy(mcip_mrp, mrp, sizeof (mac_resource_props_t));
}

/*
 * Return the effective properties currently associated with the specified
 * MAC client.
 */
void
mac_client_get_effective_resources(mac_client_handle_t mch,
    mac_resource_props_t *mrp)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_resource_props_t    *mcip_mrp = MCIP_EFFECTIVE_PROPS(mcip);

        bcopy(mcip_mrp, mrp, sizeof (mac_resource_props_t));
}

/*
 * Pass a copy of the specified packet to the promiscuous callbacks
 * of the specified MAC.
 *
 * If sender is NULL, the function is being invoked for a packet chain
 * received from the wire. If sender is non-NULL, it points to
 * the MAC client from which the packet is being sent.
 *
 * The packets are distributed to the promiscuous callbacks as follows:
 *
 * - all packets are sent to the MAC_CLIENT_PROMISC_ALL callbacks
 * - all broadcast and multicast packets are sent to the
 *   MAC_CLIENT_PROMISC_FILTER and MAC_CLIENT_PROMISC_MULTI.
 *
 * The unicast packets of MAC_CLIENT_PROMISC_FILTER callbacks are dispatched
 * after classification by mac_rx_deliver().
 */

static void
mac_promisc_dispatch_one(mac_promisc_impl_t *mpip, mblk_t *mp,
    boolean_t loopback)
{
        mblk_t *mp_copy, *mp_next;

        if (!mpip->mpi_no_copy || mpip->mpi_strip_vlan_tag) {
                mp_copy = copymsg(mp);
                if (mp_copy == NULL)
                        return;

                if (mpip->mpi_strip_vlan_tag) {
                        mp_copy = mac_strip_vlan_tag_chain(mp_copy);
                        if (mp_copy == NULL)
                                return;
                }
                mp_next = NULL;
        } else {
                mp_copy = mp;
                mp_next = mp->b_next;
        }
        mp_copy->b_next = NULL;

        mpip->mpi_fn(mpip->mpi_arg, NULL, mp_copy, loopback);
        if (mp_copy == mp)
                mp->b_next = mp_next;
}

/*
 * Return the VID of a packet. Zero if the packet is not tagged.
 */
static uint16_t
mac_ether_vid(mblk_t *mp)
{
        struct ether_header *eth = (struct ether_header *)mp->b_rptr;

        if (ntohs(eth->ether_type) == ETHERTYPE_VLAN) {
                struct ether_vlan_header *t_evhp =
                    (struct ether_vlan_header *)mp->b_rptr;
                return (VLAN_ID(ntohs(t_evhp->ether_tci)));
        }

        return (0);
}

/*
 * Return whether the specified packet contains a multicast or broadcast
 * destination MAC address.
 */
static boolean_t
mac_is_mcast(mac_impl_t *mip, mblk_t *mp)
{
        mac_header_info_t hdr_info;

        if (mac_header_info((mac_handle_t)mip, mp, &hdr_info) != 0)
                return (B_FALSE);
        return ((hdr_info.mhi_dsttype == MAC_ADDRTYPE_BROADCAST) ||
            (hdr_info.mhi_dsttype == MAC_ADDRTYPE_MULTICAST));
}

/*
 * Send a copy of an mblk chain to the MAC clients of the specified MAC.
 * "sender" points to the sender MAC client for outbound packets, and
 * is set to NULL for inbound packets.
 */
void
mac_promisc_dispatch(mac_impl_t *mip, mblk_t *mp_chain,
    mac_client_impl_t *sender)
{
        mac_promisc_impl_t *mpip;
        mac_cb_t *mcb;
        mblk_t *mp;
        boolean_t is_mcast, is_sender;

        MAC_PROMISC_WALKER_INC(mip);
        for (mp = mp_chain; mp != NULL; mp = mp->b_next) {
                is_mcast = mac_is_mcast(mip, mp);
                /* send packet to interested callbacks */
                for (mcb = mip->mi_promisc_list; mcb != NULL;
                    mcb = mcb->mcb_nextp) {
                        mpip = (mac_promisc_impl_t *)mcb->mcb_objp;
                        is_sender = (mpip->mpi_mcip == sender);

                        if (is_sender && mpip->mpi_no_tx_loop)
                                /*
                                 * The sender doesn't want to receive
                                 * copies of the packets it sends.
                                 */
                                continue;

                        /* this client doesn't need any packets (bridge) */
                        if (mpip->mpi_fn == NULL)
                                continue;

                        /*
                         * For an ethernet MAC, don't displatch a multicast
                         * packet to a non-PROMISC_ALL callbacks unless the VID
                         * of the packet matches the VID of the client.
                         */
                        if (is_mcast &&
                            mpip->mpi_type != MAC_CLIENT_PROMISC_ALL &&
                            !mac_client_check_flow_vid(mpip->mpi_mcip,
                            mac_ether_vid(mp)))
                                continue;

                        if (is_sender ||
                            mpip->mpi_type == MAC_CLIENT_PROMISC_ALL ||
                            is_mcast)
                                mac_promisc_dispatch_one(mpip, mp, is_sender);
                }
        }
        MAC_PROMISC_WALKER_DCR(mip);
}

void
mac_promisc_client_dispatch(mac_client_impl_t *mcip, mblk_t *mp_chain)
{
        mac_impl_t              *mip = mcip->mci_mip;
        mac_promisc_impl_t      *mpip;
        boolean_t               is_mcast;
        mblk_t                  *mp;
        mac_cb_t                *mcb;

        /*
         * The unicast packets for the MAC client still
         * need to be delivered to the MAC_CLIENT_PROMISC_FILTERED
         * promiscuous callbacks. The broadcast and multicast
         * packets were delivered from mac_rx().
         */
        MAC_PROMISC_WALKER_INC(mip);
        for (mp = mp_chain; mp != NULL; mp = mp->b_next) {
                is_mcast = mac_is_mcast(mip, mp);
                for (mcb = mcip->mci_promisc_list; mcb != NULL;
                    mcb = mcb->mcb_nextp) {
                        mpip = (mac_promisc_impl_t *)mcb->mcb_objp;
                        if (mpip->mpi_type == MAC_CLIENT_PROMISC_FILTERED &&
                            !is_mcast) {
                                mac_promisc_dispatch_one(mpip, mp, B_FALSE);
                        }
                }
        }
        MAC_PROMISC_WALKER_DCR(mip);
}

/*
 * Return the margin value currently assigned to the specified MAC instance.
 */
void
mac_margin_get(mac_handle_t mh, uint32_t *marginp)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        rw_enter(&(mip->mi_rw_lock), RW_READER);
        *marginp = mip->mi_margin;
        rw_exit(&(mip->mi_rw_lock));
}

/*
 * mac_info_get() is used for retrieving the mac_info when a DL_INFO_REQ is
 * issued before a DL_ATTACH_REQ. we walk the i_mac_impl_hash table and find
 * the first mac_impl_t with a matching driver name; then we copy its mac_info_t
 * to the caller. we do all this with i_mac_impl_lock held so the mac_impl_t
 * cannot disappear while we are accessing it.
 */
typedef struct i_mac_info_state_s {
        const char      *mi_name;
        mac_info_t      *mi_infop;
} i_mac_info_state_t;

/*ARGSUSED*/
static uint_t
i_mac_info_walker(mod_hash_key_t key, mod_hash_val_t *val, void *arg)
{
        i_mac_info_state_t *statep = arg;
        mac_impl_t *mip = (mac_impl_t *)val;

        if (mip->mi_state_flags & MIS_DISABLED)
                return (MH_WALK_CONTINUE);

        if (strcmp(statep->mi_name,
            ddi_driver_name(mip->mi_dip)) != 0)
                return (MH_WALK_CONTINUE);

        statep->mi_infop = &mip->mi_info;
        return (MH_WALK_TERMINATE);
}

boolean_t
mac_info_get(const char *name, mac_info_t *minfop)
{
        i_mac_info_state_t state;

        rw_enter(&i_mac_impl_lock, RW_READER);
        state.mi_name = name;
        state.mi_infop = NULL;
        mod_hash_walk(i_mac_impl_hash, i_mac_info_walker, &state);
        if (state.mi_infop == NULL) {
                rw_exit(&i_mac_impl_lock);
                return (B_FALSE);
        }
        *minfop = *state.mi_infop;
        rw_exit(&i_mac_impl_lock);
        return (B_TRUE);
}

/*
 * To get the capabilities that MAC layer cares about, such as rings, factory
 * mac address, vnic or not, it should directly invoke this function.  If the
 * link is part of a bridge, then the only "capability" it has is the inability
 * to do zero copy.
 */
boolean_t
i_mac_capab_get(mac_handle_t mh, mac_capab_t cap, void *cap_data)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        if (mip->mi_bridge_link != NULL)
                return (cap == MAC_CAPAB_NO_ZCOPY);
        else if (mip->mi_callbacks->mc_callbacks & MC_GETCAPAB)
                return (mip->mi_getcapab(mip->mi_driver, cap, cap_data));
        else
                return (B_FALSE);
}

/*
 * Capability query function. If number of active mac clients is greater than
 * 1, only limited capabilities can be advertised to the caller no matter the
 * driver has certain capability or not. Else, we query the driver to get the
 * capability.
 */
boolean_t
mac_capab_get(mac_handle_t mh, mac_capab_t cap, void *cap_data)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        /*
         * if mi_nactiveclients > 1, only MAC_CAPAB_LEGACY, MAC_CAPAB_HCKSUM,
         * MAC_CAPAB_NO_NATIVEVLAN and MAC_CAPAB_NO_ZCOPY can be advertised.
         */
        if (mip->mi_nactiveclients > 1) {
                switch (cap) {
                case MAC_CAPAB_NO_ZCOPY:
                        return (B_TRUE);
                case MAC_CAPAB_LEGACY:
                case MAC_CAPAB_HCKSUM:
                case MAC_CAPAB_NO_NATIVEVLAN:
                        break;
                default:
                        return (B_FALSE);
                }
        }

        /* else get capab from driver */
        return (i_mac_capab_get(mh, cap, cap_data));
}

boolean_t
mac_sap_verify(mac_handle_t mh, uint32_t sap, uint32_t *bind_sap)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_type->mt_ops.mtops_sap_verify(sap, bind_sap,
            mip->mi_pdata));
}

mblk_t *
mac_header(mac_handle_t mh, const uint8_t *daddr, uint32_t sap, mblk_t *payload,
    size_t extra_len)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        const uint8_t   *hdr_daddr;

        /*
         * If the MAC is point-to-point with a fixed destination address, then
         * we must always use that destination in the MAC header.
         */
        hdr_daddr = (mip->mi_dstaddr_set ? mip->mi_dstaddr : daddr);
        return (mip->mi_type->mt_ops.mtops_header(mip->mi_addr, hdr_daddr, sap,
            mip->mi_pdata, payload, extra_len));
}

int
mac_header_info(mac_handle_t mh, mblk_t *mp, mac_header_info_t *mhip)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_type->mt_ops.mtops_header_info(mp, mip->mi_pdata,
            mhip));
}

int
mac_vlan_header_info(mac_handle_t mh, mblk_t *mp, mac_header_info_t *mhip)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        boolean_t       is_ethernet = (mip->mi_info.mi_media == DL_ETHER);
        int             err = 0;

        /*
         * Packets should always be at least 16 bit aligned.
         */
        ASSERT(IS_P2ALIGNED(mp->b_rptr, sizeof (uint16_t)));

        if ((err = mac_header_info(mh, mp, mhip)) != 0)
                return (err);

        /*
         * If this is a VLAN-tagged Ethernet packet, then the SAP in the
         * mac_header_info_t as returned by mac_header_info() is
         * ETHERTYPE_VLAN. We need to grab the ethertype from the VLAN header.
         */
        if (is_ethernet && (mhip->mhi_bindsap == ETHERTYPE_VLAN)) {
                struct ether_vlan_header *evhp;
                uint16_t sap;
                mblk_t *tmp = NULL;
                size_t size;

                size = sizeof (struct ether_vlan_header);
                if (MBLKL(mp) < size) {
                        /*
                         * Pullup the message in order to get the MAC header
                         * infomation. Note that this is a read-only function,
                         * we keep the input packet intact.
                         */
                        if ((tmp = msgpullup(mp, size)) == NULL)
                                return (EINVAL);

                        mp = tmp;
                }
                evhp = (struct ether_vlan_header *)mp->b_rptr;
                sap = ntohs(evhp->ether_type);
                (void) mac_sap_verify(mh, sap, &mhip->mhi_bindsap);
                mhip->mhi_hdrsize = sizeof (struct ether_vlan_header);
                mhip->mhi_tci = ntohs(evhp->ether_tci);
                mhip->mhi_istagged = B_TRUE;
                freemsg(tmp);

                if (VLAN_CFI(mhip->mhi_tci) != ETHER_CFI)
                        return (EINVAL);
        } else {
                mhip->mhi_istagged = B_FALSE;
                mhip->mhi_tci = 0;
        }

        return (0);
}

mblk_t *
mac_header_cook(mac_handle_t mh, mblk_t *mp)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        if (mip->mi_type->mt_ops.mtops_ops & MTOPS_HEADER_COOK) {
                if (DB_REF(mp) > 1) {
                        mblk_t *newmp = copymsg(mp);
                        if (newmp == NULL)
                                return (NULL);
                        freemsg(mp);
                        mp = newmp;
                }
                return (mip->mi_type->mt_ops.mtops_header_cook(mp,
                    mip->mi_pdata));
        }
        return (mp);
}

mblk_t *
mac_header_uncook(mac_handle_t mh, mblk_t *mp)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        if (mip->mi_type->mt_ops.mtops_ops & MTOPS_HEADER_UNCOOK) {
                if (DB_REF(mp) > 1) {
                        mblk_t *newmp = copymsg(mp);
                        if (newmp == NULL)
                                return (NULL);
                        freemsg(mp);
                        mp = newmp;
                }
                return (mip->mi_type->mt_ops.mtops_header_uncook(mp,
                    mip->mi_pdata));
        }
        return (mp);
}

uint_t
mac_addr_len(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_type->mt_addr_length);
}

/* True if a MAC is a VNIC */
boolean_t
mac_is_vnic(mac_handle_t mh)
{
        return (((mac_impl_t *)mh)->mi_state_flags & MIS_IS_VNIC);
}

mac_handle_t
mac_get_lower_mac_handle(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(mac_is_vnic(mh));
        return (((vnic_t *)mip->mi_driver)->vn_lower_mh);
}

boolean_t
mac_is_vnic_primary(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(mac_is_vnic(mh));
        return (((vnic_t *)mip->mi_driver)->vn_addr_type ==
            VNIC_MAC_ADDR_TYPE_PRIMARY);
}

void
mac_update_resources(mac_resource_props_t *nmrp, mac_resource_props_t *cmrp,
    boolean_t is_user_flow)
{
        if (nmrp != NULL && cmrp != NULL) {
                if (nmrp->mrp_mask & MRP_PRIORITY) {
                        if (nmrp->mrp_priority == MPL_RESET) {
                                cmrp->mrp_mask &= ~MRP_PRIORITY;
                                if (is_user_flow) {
                                        cmrp->mrp_priority =
                                            MPL_SUBFLOW_DEFAULT;
                                } else {
                                        cmrp->mrp_priority = MPL_LINK_DEFAULT;
                                }
                        } else {
                                cmrp->mrp_mask |= MRP_PRIORITY;
                                cmrp->mrp_priority = nmrp->mrp_priority;
                        }
                }
                if (nmrp->mrp_mask & MRP_MAXBW) {
                        if (nmrp->mrp_maxbw == MRP_MAXBW_RESETVAL) {
                                cmrp->mrp_mask &= ~MRP_MAXBW;
                                cmrp->mrp_maxbw = 0;
                        } else {
                                cmrp->mrp_mask |= MRP_MAXBW;
                                cmrp->mrp_maxbw = nmrp->mrp_maxbw;
                        }
                }
                if (nmrp->mrp_mask & MRP_CPUS)
                        MAC_COPY_CPUS(nmrp, cmrp);

                if (nmrp->mrp_mask & MRP_POOL) {
                        if (strlen(nmrp->mrp_pool) == 0) {
                                cmrp->mrp_mask &= ~MRP_POOL;
                                bzero(cmrp->mrp_pool, sizeof (cmrp->mrp_pool));
                        } else {
                                cmrp->mrp_mask |= MRP_POOL;
                                (void) strncpy(cmrp->mrp_pool, nmrp->mrp_pool,
                                    sizeof (cmrp->mrp_pool));
                        }

                }

                if (nmrp->mrp_mask & MRP_PROTECT)
                        mac_protect_update(nmrp, cmrp);

                /*
                 * Update the rings specified.
                 */
                if (nmrp->mrp_mask & MRP_RX_RINGS) {
                        if (nmrp->mrp_mask & MRP_RINGS_RESET) {
                                cmrp->mrp_mask &= ~MRP_RX_RINGS;
                                if (cmrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                                        cmrp->mrp_mask &= ~MRP_RXRINGS_UNSPEC;
                                cmrp->mrp_nrxrings = 0;
                        } else {
                                cmrp->mrp_mask |= MRP_RX_RINGS;
                                cmrp->mrp_nrxrings = nmrp->mrp_nrxrings;
                        }
                }
                if (nmrp->mrp_mask & MRP_TX_RINGS) {
                        if (nmrp->mrp_mask & MRP_RINGS_RESET) {
                                cmrp->mrp_mask &= ~MRP_TX_RINGS;
                                if (cmrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                                        cmrp->mrp_mask &= ~MRP_TXRINGS_UNSPEC;
                                cmrp->mrp_ntxrings = 0;
                        } else {
                                cmrp->mrp_mask |= MRP_TX_RINGS;
                                cmrp->mrp_ntxrings = nmrp->mrp_ntxrings;
                        }
                }
                if (nmrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                        cmrp->mrp_mask |= MRP_RXRINGS_UNSPEC;
                else if (cmrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                        cmrp->mrp_mask &= ~MRP_RXRINGS_UNSPEC;

                if (nmrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                        cmrp->mrp_mask |= MRP_TXRINGS_UNSPEC;
                else if (cmrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                        cmrp->mrp_mask &= ~MRP_TXRINGS_UNSPEC;
        }
}

/*
 * i_mac_set_resources:
 *
 * This routine associates properties with the primary MAC client of
 * the specified MAC instance.
 * - Cache the properties in mac_impl_t
 * - Apply the properties to the primary MAC client if exists
 */
int
i_mac_set_resources(mac_handle_t mh, mac_resource_props_t *mrp)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_client_impl_t       *mcip;
        int                     err = 0;
        uint32_t                resmask, newresmask;
        mac_resource_props_t    *tmrp, *umrp;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        err = mac_validate_props(mip, mrp);
        if (err != 0)
                return (err);

        umrp = kmem_zalloc(sizeof (*umrp), KM_SLEEP);
        bcopy(&mip->mi_resource_props, umrp, sizeof (*umrp));
        resmask = umrp->mrp_mask;
        mac_update_resources(mrp, umrp, B_FALSE);
        newresmask = umrp->mrp_mask;

        if (resmask == 0 && newresmask != 0) {
                /*
                 * Bandwidth, priority, cpu or pool link properties configured,
                 * must disable fastpath.
                 */
                if ((err = mac_fastpath_disable((mac_handle_t)mip)) != 0) {
                        kmem_free(umrp, sizeof (*umrp));
                        return (err);
                }
        }

        /*
         * Since bind_cpu may be modified by mac_client_set_resources()
         * we use a copy of bind_cpu and finally cache bind_cpu in mip.
         * This allows us to cache only user edits in mip.
         */
        tmrp = kmem_zalloc(sizeof (*tmrp), KM_SLEEP);
        bcopy(mrp, tmrp, sizeof (*tmrp));
        mcip = mac_primary_client_handle(mip);
        if (mcip != NULL && (mcip->mci_state_flags & MCIS_IS_AGGR_PORT) == 0) {
                err = mac_client_set_resources((mac_client_handle_t)mcip, tmrp);
        } else if ((mrp->mrp_mask & MRP_RX_RINGS ||
            mrp->mrp_mask & MRP_TX_RINGS)) {
                mac_client_impl_t       *vmcip;

                /*
                 * If the primary is not up, we need to check if there
                 * are any VLANs on this primary. If there are then
                 * we need to set this property on the VLANs since
                 * VLANs follow the primary they are based on. Just
                 * look for the first VLAN and change its properties,
                 * all the other VLANs should be in the same group.
                 */
                for (vmcip = mip->mi_clients_list; vmcip != NULL;
                    vmcip = vmcip->mci_client_next) {
                        if ((vmcip->mci_flent->fe_type & FLOW_PRIMARY_MAC) &&
                            mac_client_vid((mac_client_handle_t)vmcip) !=
                            VLAN_ID_NONE) {
                                break;
                        }
                }
                if (vmcip != NULL) {
                        mac_resource_props_t    *omrp;
                        mac_resource_props_t    *vmrp;

                        omrp = kmem_zalloc(sizeof (*omrp), KM_SLEEP);
                        bcopy(MCIP_RESOURCE_PROPS(vmcip), omrp, sizeof (*omrp));
                        /*
                         * We dont' call mac_update_resources since we
                         * want to take only the ring properties and
                         * not all the properties that may have changed.
                         */
                        vmrp = MCIP_RESOURCE_PROPS(vmcip);
                        if (mrp->mrp_mask & MRP_RX_RINGS) {
                                if (mrp->mrp_mask & MRP_RINGS_RESET) {
                                        vmrp->mrp_mask &= ~MRP_RX_RINGS;
                                        if (vmrp->mrp_mask &
                                            MRP_RXRINGS_UNSPEC) {
                                                vmrp->mrp_mask &=
                                                    ~MRP_RXRINGS_UNSPEC;
                                        }
                                        vmrp->mrp_nrxrings = 0;
                                } else {
                                        vmrp->mrp_mask |= MRP_RX_RINGS;
                                        vmrp->mrp_nrxrings = mrp->mrp_nrxrings;
                                }
                        }
                        if (mrp->mrp_mask & MRP_TX_RINGS) {
                                if (mrp->mrp_mask & MRP_RINGS_RESET) {
                                        vmrp->mrp_mask &= ~MRP_TX_RINGS;
                                        if (vmrp->mrp_mask &
                                            MRP_TXRINGS_UNSPEC) {
                                                vmrp->mrp_mask &=
                                                    ~MRP_TXRINGS_UNSPEC;
                                        }
                                        vmrp->mrp_ntxrings = 0;
                                } else {
                                        vmrp->mrp_mask |= MRP_TX_RINGS;
                                        vmrp->mrp_ntxrings = mrp->mrp_ntxrings;
                                }
                        }
                        if (mrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                                vmrp->mrp_mask |= MRP_RXRINGS_UNSPEC;

                        if (mrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                                vmrp->mrp_mask |= MRP_TXRINGS_UNSPEC;

                        if ((err = mac_client_set_rings_prop(vmcip, mrp,
                            omrp)) != 0) {
                                bcopy(omrp, MCIP_RESOURCE_PROPS(vmcip),
                                    sizeof (*omrp));
                        } else {
                                mac_set_prim_vlan_rings(mip, vmrp);
                        }
                        kmem_free(omrp, sizeof (*omrp));
                }
        }

        /* Only update the values if mac_client_set_resources succeeded */
        if (err == 0) {
                bcopy(umrp, &mip->mi_resource_props, sizeof (*umrp));
                /*
                 * If bandwidth, priority or cpu link properties cleared,
                 * renable fastpath.
                 */
                if (resmask != 0 && newresmask == 0)
                        mac_fastpath_enable((mac_handle_t)mip);
        } else if (resmask == 0 && newresmask != 0) {
                mac_fastpath_enable((mac_handle_t)mip);
        }
        kmem_free(tmrp, sizeof (*tmrp));
        kmem_free(umrp, sizeof (*umrp));
        return (err);
}

int
mac_set_resources(mac_handle_t mh, mac_resource_props_t *mrp)
{
        int err;

        i_mac_perim_enter((mac_impl_t *)mh);
        err = i_mac_set_resources(mh, mrp);
        i_mac_perim_exit((mac_impl_t *)mh);
        return (err);
}

/*
 * Get the properties cached for the specified MAC instance.
 */
void
mac_get_resources(mac_handle_t mh, mac_resource_props_t *mrp)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_client_impl_t       *mcip;

        mcip = mac_primary_client_handle(mip);
        if (mcip != NULL) {
                mac_client_get_resources((mac_client_handle_t)mcip, mrp);
                return;
        }
        bcopy(&mip->mi_resource_props, mrp, sizeof (mac_resource_props_t));
}

/*
 * Get the effective properties from the primary client of the
 * specified MAC instance.
 */
void
mac_get_effective_resources(mac_handle_t mh, mac_resource_props_t *mrp)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_client_impl_t       *mcip;

        mcip = mac_primary_client_handle(mip);
        if (mcip != NULL) {
                mac_client_get_effective_resources((mac_client_handle_t)mcip,
                    mrp);
                return;
        }
        bzero(mrp, sizeof (mac_resource_props_t));
}

int
mac_set_pvid(mac_handle_t mh, uint16_t pvid)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_client_impl_t *mcip;
        mac_unicast_impl_t *muip;

        i_mac_perim_enter(mip);
        if (pvid != 0) {
                for (mcip = mip->mi_clients_list; mcip != NULL;
                    mcip = mcip->mci_client_next) {
                        for (muip = mcip->mci_unicast_list; muip != NULL;
                            muip = muip->mui_next) {
                                if (muip->mui_vid == pvid) {
                                        i_mac_perim_exit(mip);
                                        return (EBUSY);
                                }
                        }
                }
        }
        mip->mi_pvid = pvid;
        i_mac_perim_exit(mip);
        return (0);
}

uint16_t
mac_get_pvid(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_pvid);
}

uint32_t
mac_get_llimit(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_llimit);
}

uint32_t
mac_get_ldecay(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_ldecay);
}

/*
 * Rename a mac client, its flow, and the kstat.
 */
int
mac_rename_primary(mac_handle_t mh, const char *new_name)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_client_impl_t       *cur_clnt = NULL;
        flow_entry_t            *fep;

        i_mac_perim_enter(mip);

        /*
         * VNICs: we need to change the sys flow name and
         * the associated flow kstat.
         */
        if (mip->mi_state_flags & MIS_IS_VNIC) {
                mac_client_impl_t *mcip = mac_vnic_lower(mip);
                ASSERT(new_name != NULL);
                mac_rename_flow_names(mcip, new_name);
                mac_stat_rename(mcip);
                goto done;
        }
        /*
         * This mac may itself be an aggr link, or it may have some client
         * which is an aggr port. For both cases, we need to change the
         * aggr port's mac client name, its flow name and the associated flow
         * kstat.
         */
        if (mip->mi_state_flags & MIS_IS_AGGR) {
                mac_capab_aggr_t aggr_cap;
                mac_rename_fn_t rename_fn;
                boolean_t ret;

                ASSERT(new_name != NULL);
                ret = i_mac_capab_get((mac_handle_t)mip, MAC_CAPAB_AGGR,
                    (void *)(&aggr_cap));
                ASSERT(ret == B_TRUE);
                rename_fn = aggr_cap.mca_rename_fn;
                rename_fn(new_name, mip->mi_driver);
                /*
                 * The aggr's client name and kstat flow name will be
                 * updated below, i.e. via mac_rename_flow_names.
                 */
        }

        for (cur_clnt = mip->mi_clients_list; cur_clnt != NULL;
            cur_clnt = cur_clnt->mci_client_next) {
                if (cur_clnt->mci_state_flags & MCIS_IS_AGGR_PORT) {
                        if (new_name != NULL) {
                                char *str_st = cur_clnt->mci_name;
                                char *str_del = strchr(str_st, '-');

                                ASSERT(str_del != NULL);
                                bzero(str_del + 1, MAXNAMELEN -
                                    (str_del - str_st + 1));
                                bcopy(new_name, str_del + 1,
                                    strlen(new_name));
                        }
                        fep = cur_clnt->mci_flent;
                        mac_rename_flow(fep, cur_clnt->mci_name);
                        break;
                } else if (new_name != NULL &&
                    cur_clnt->mci_state_flags & MCIS_USE_DATALINK_NAME) {
                        mac_rename_flow_names(cur_clnt, new_name);
                        break;
                }
        }

        /* Recreate kstats associated with aggr pseudo rings */
        if (mip->mi_state_flags & MIS_IS_AGGR)
                mac_pseudo_ring_stat_rename(mip);

done:
        i_mac_perim_exit(mip);
        return (0);
}

/*
 * Rename the MAC client's flow names
 */
static void
mac_rename_flow_names(mac_client_impl_t *mcip, const char *new_name)
{
        flow_entry_t    *flent;
        uint16_t        vid;
        char            flowname[MAXFLOWNAMELEN];
        mac_impl_t      *mip = mcip->mci_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        /*
         * Use mi_rw_lock to ensure that threads not in the mac perimeter
         * see a self-consistent value for mci_name
         */
        rw_enter(&mip->mi_rw_lock, RW_WRITER);
        (void) strlcpy(mcip->mci_name, new_name, sizeof (mcip->mci_name));
        rw_exit(&mip->mi_rw_lock);

        mac_rename_flow(mcip->mci_flent, new_name);

        if (mcip->mci_nflents == 1)
                return;

        /*
         * We have to rename all the others too, no stats to destroy for
         * these.
         */
        for (flent = mcip->mci_flent_list; flent != NULL;
            flent = flent->fe_client_next) {
                if (flent != mcip->mci_flent) {
                        vid = i_mac_flow_vid(flent);
                        (void) sprintf(flowname, "%s%u", new_name, vid);
                        mac_flow_set_name(flent, flowname);
                }
        }
}


/*
 * Add a flow to the MAC client's flow list - i.e list of MAC/VID tuples
 * defined for the specified MAC client.
 */
static void
mac_client_add_to_flow_list(mac_client_impl_t *mcip, flow_entry_t *flent)
{
        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));
        /*
         * The promisc Rx data path walks the mci_flent_list. Protect by
         * using mi_rw_lock
         */
        rw_enter(&mcip->mci_rw_lock, RW_WRITER);

        /* Add it to the head */
        flent->fe_client_next = mcip->mci_flent_list;
        mcip->mci_flent_list = flent;
        mcip->mci_nflents++;

        /*
         * Keep track of the number of non-zero VIDs addresses per MAC
         * client to avoid figuring it out in the data-path.
         */
        if (i_mac_flow_vid(flent) != VLAN_ID_NONE)
                mcip->mci_nvids++;

        rw_exit(&mcip->mci_rw_lock);
}

/*
 * Remove a flow entry from the MAC client's list.
 */
static void
mac_client_remove_flow_from_list(mac_client_impl_t *mcip, flow_entry_t *flent)
{
        flow_entry_t    *fe = mcip->mci_flent_list;
        flow_entry_t    *prev_fe = NULL;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));
        /*
         * The promisc Rx data path walks the mci_flent_list. Protect by
         * using mci_rw_lock
         */
        rw_enter(&mcip->mci_rw_lock, RW_WRITER);
        while ((fe != NULL) && (fe != flent)) {
                prev_fe = fe;
                fe = fe->fe_client_next;
        }

        ASSERT(fe != NULL);
        if (prev_fe == NULL) {
                /* Deleting the first node */
                mcip->mci_flent_list = fe->fe_client_next;
        } else {
                prev_fe->fe_client_next = fe->fe_client_next;
        }
        mcip->mci_nflents--;

        if (i_mac_flow_vid(flent) != VLAN_ID_NONE)
                mcip->mci_nvids--;

        rw_exit(&mcip->mci_rw_lock);
}

/*
 * Check if the given VID belongs to this MAC client.
 */
boolean_t
mac_client_check_flow_vid(mac_client_impl_t *mcip, uint16_t vid)
{
        flow_entry_t    *flent;
        uint16_t        mci_vid;

        /* The mci_flent_list is protected by mci_rw_lock */
        rw_enter(&mcip->mci_rw_lock, RW_WRITER);
        for (flent = mcip->mci_flent_list; flent != NULL;
            flent = flent->fe_client_next) {
                mci_vid = i_mac_flow_vid(flent);
                if (vid == mci_vid) {
                        rw_exit(&mcip->mci_rw_lock);
                        return (B_TRUE);
                }
        }
        rw_exit(&mcip->mci_rw_lock);
        return (B_FALSE);
}

/*
 * Get the flow entry for the specified <MAC addr, VID> tuple.
 */
static flow_entry_t *
mac_client_get_flow(mac_client_impl_t *mcip, mac_unicast_impl_t *muip)
{
        mac_address_t *map = mcip->mci_unicast;
        flow_entry_t *flent;
        uint16_t vid;
        flow_desc_t flow_desc;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        mac_flow_get_desc(mcip->mci_flent, &flow_desc);
        if (bcmp(flow_desc.fd_dst_mac, map->ma_addr, map->ma_len) != 0)
                return (NULL);

        for (flent = mcip->mci_flent_list; flent != NULL;
            flent = flent->fe_client_next) {
                vid = i_mac_flow_vid(flent);
                if (vid == muip->mui_vid) {
                        return (flent);
                }
        }

        return (NULL);
}

/*
 * Since mci_flent has the SRSs, when we want to remove it, we replace
 * the flow_desc_t in mci_flent with that of an existing flent and then
 * remove that flent instead of mci_flent.
 */
static flow_entry_t *
mac_client_swap_mciflent(mac_client_impl_t *mcip)
{
        flow_entry_t    *flent = mcip->mci_flent;
        flow_tab_t      *ft = flent->fe_flow_tab;
        flow_entry_t    *flent1;
        flow_desc_t     fl_desc;
        char            fl_name[MAXFLOWNAMELEN];
        int             err;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));
        ASSERT(mcip->mci_nflents > 1);

        /* get the next flent following the primary flent  */
        flent1 = mcip->mci_flent_list->fe_client_next;
        ASSERT(flent1 != NULL && flent1->fe_flow_tab == ft);

        /*
         * Remove the flent from the flow table before updating the
         * flow descriptor as the hash depends on the flow descriptor.
         * This also helps incoming packet classification avoid having
         * to grab fe_lock. Access to fe_flow_desc of a flent not in the
         * flow table is done under the fe_lock so that log or stat functions
         * see a self-consistent fe_flow_desc. The name and desc are specific
         * to a flow, the rest are shared by all the clients, including
         * resource control etc.
         */
        mac_flow_remove(ft, flent, B_TRUE);
        mac_flow_remove(ft, flent1, B_TRUE);

        bcopy(&flent->fe_flow_desc, &fl_desc, sizeof (flow_desc_t));
        bcopy(flent->fe_flow_name, fl_name, MAXFLOWNAMELEN);

        /* update the primary flow entry */
        mutex_enter(&flent->fe_lock);
        bcopy(&flent1->fe_flow_desc, &flent->fe_flow_desc,
            sizeof (flow_desc_t));
        bcopy(&flent1->fe_flow_name, &flent->fe_flow_name, MAXFLOWNAMELEN);
        mutex_exit(&flent->fe_lock);

        /* update the flow entry that is to be freed */
        mutex_enter(&flent1->fe_lock);
        bcopy(&fl_desc, &flent1->fe_flow_desc, sizeof (flow_desc_t));
        bcopy(fl_name, &flent1->fe_flow_name, MAXFLOWNAMELEN);
        mutex_exit(&flent1->fe_lock);

        /* now reinsert the flow entries in the table */
        err = mac_flow_add(ft, flent);
        ASSERT(err == 0);

        err = mac_flow_add(ft, flent1);
        ASSERT(err == 0);

        return (flent1);
}

/*
 * Return whether there is only one flow entry associated with this
 * MAC client.
 */
static boolean_t
mac_client_single_rcvr(mac_client_impl_t *mcip)
{
        return (mcip->mci_nflents == 1);
}

int
mac_validate_props(mac_impl_t *mip, mac_resource_props_t *mrp)
{
        boolean_t               reset;
        uint32_t                rings_needed;
        uint32_t                rings_avail;
        mac_group_type_t        gtype;
        mac_resource_props_t    *mip_mrp;

        if (mrp == NULL)
                return (0);

        if (mrp->mrp_mask & MRP_PRIORITY) {
                mac_priority_level_t    pri = mrp->mrp_priority;

                if (pri < MPL_LOW || pri > MPL_RESET)
                        return (EINVAL);
        }

        if (mrp->mrp_mask & MRP_MAXBW) {
                uint64_t maxbw = mrp->mrp_maxbw;

                if (maxbw < MRP_MAXBW_MINVAL && maxbw != 0)
                        return (EINVAL);
        }
        if (mrp->mrp_mask & MRP_CPUS) {
                int i, j;
                mac_cpu_mode_t  fanout;

                if (mrp->mrp_ncpus > ncpus)
                        return (EINVAL);

                for (i = 0; i < mrp->mrp_ncpus; i++) {
                        for (j = 0; j < mrp->mrp_ncpus; j++) {
                                if (i != j &&
                                    mrp->mrp_cpu[i] == mrp->mrp_cpu[j]) {
                                        return (EINVAL);
                                }
                        }
                }

                for (i = 0; i < mrp->mrp_ncpus; i++) {
                        cpu_t *cp;
                        int rv;

                        mutex_enter(&cpu_lock);
                        cp = cpu_get(mrp->mrp_cpu[i]);
                        if (cp != NULL)
                                rv = cpu_is_online(cp);
                        else
                                rv = 0;
                        mutex_exit(&cpu_lock);
                        if (rv == 0)
                                return (EINVAL);
                }

                fanout = mrp->mrp_fanout_mode;
                if (fanout < 0 || fanout > MCM_CPUS)
                        return (EINVAL);
        }

        if (mrp->mrp_mask & MRP_PROTECT) {
                int err = mac_protect_validate(mrp);
                if (err != 0)
                        return (err);
        }

        if (!(mrp->mrp_mask & MRP_RX_RINGS) &&
            !(mrp->mrp_mask & MRP_TX_RINGS)) {
                return (0);
        }

        /*
         * mip will be null when we come from mac_flow_create or
         * mac_link_flow_modify. In the latter case it is a user flow,
         * for which we don't support rings. In the former we would
         * have validated the props beforehand (i_mac_unicast_add ->
         * mac_client_set_resources -> validate for the primary and
         * vnic_dev_create -> mac_client_set_resources -> validate for
         * a vnic.
         */
        if (mip == NULL)
                return (0);

        /*
         * We don't support setting rings property for a VNIC that is using a
         * primary address (VLAN)
         */
        if ((mip->mi_state_flags & MIS_IS_VNIC) &&
            mac_is_vnic_primary((mac_handle_t)mip)) {
                return (ENOTSUP);
        }

        mip_mrp = &mip->mi_resource_props;
        /*
         * The rings property should be validated against the NICs
         * resources
         */
        if (mip->mi_state_flags & MIS_IS_VNIC)
                mip = (mac_impl_t *)mac_get_lower_mac_handle((mac_handle_t)mip);

        reset = mrp->mrp_mask & MRP_RINGS_RESET;
        /*
         * If groups are not supported, return error.
         */
        if (((mrp->mrp_mask & MRP_RX_RINGS) && mip->mi_rx_groups == NULL) ||
            ((mrp->mrp_mask & MRP_TX_RINGS) && mip->mi_tx_groups == NULL)) {
                return (EINVAL);
        }
        /*
         * If we are just resetting, there is no validation needed.
         */
        if (reset)
                return (0);

        if (mrp->mrp_mask & MRP_RX_RINGS) {
                rings_needed = mrp->mrp_nrxrings;
                /*
                 * We just want to check if the number of additional
                 * rings requested is available.
                 */
                if (mip_mrp->mrp_mask & MRP_RX_RINGS) {
                        if (mrp->mrp_nrxrings > mip_mrp->mrp_nrxrings)
                                /* Just check for the additional rings */
                                rings_needed -= mip_mrp->mrp_nrxrings;
                        else
                                /* We are not asking for additional rings */
                                rings_needed = 0;
                }
                rings_avail = mip->mi_rxrings_avail;
                gtype = mip->mi_rx_group_type;
        } else {
                rings_needed = mrp->mrp_ntxrings;
                /* Similarly for the TX rings */
                if (mip_mrp->mrp_mask & MRP_TX_RINGS) {
                        if (mrp->mrp_ntxrings > mip_mrp->mrp_ntxrings)
                                /* Just check for the additional rings */
                                rings_needed -= mip_mrp->mrp_ntxrings;
                        else
                                /* We are not asking for additional rings */
                                rings_needed = 0;
                }
                rings_avail = mip->mi_txrings_avail;
                gtype = mip->mi_tx_group_type;
        }

        /* Error if the group is dynamic .. */
        if (gtype == MAC_GROUP_TYPE_DYNAMIC) {
                /*
                 * .. and rings specified are more than available.
                 */
                if (rings_needed > rings_avail)
                        return (EINVAL);
        } else {
                /*
                 * OR group is static and we have specified some rings.
                 */
                if (rings_needed > 0)
                        return (EINVAL);
        }
        return (0);
}

/*
 * Send a MAC_NOTE_LINK notification to all the MAC clients whenever the
 * underlying physical link is down. This is to allow MAC clients to
 * communicate with other clients.
 */
void
mac_virtual_link_update(mac_impl_t *mip)
{
        if (mip->mi_linkstate != LINK_STATE_UP)
                i_mac_notify(mip, MAC_NOTE_LINK);
}

/*
 * For clients that have a pass-thru MAC, e.g. VNIC, we set the VNIC's
 * mac handle in the client.
 */
void
mac_set_upper_mac(mac_client_handle_t mch, mac_handle_t mh,
    mac_resource_props_t *mrp)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = (mac_impl_t *)mh;

        mcip->mci_upper_mip = mip;
        /* If there are any properties, copy it over too */
        if (mrp != NULL) {
                bcopy(mrp, &mip->mi_resource_props,
                    sizeof (mac_resource_props_t));
        }
}

/*
 * Mark the mac as being used exclusively by the single mac client that is
 * doing some control operation on this mac. No further opens of this mac
 * will be allowed until this client calls mac_unmark_exclusive. The mac
 * client calling this function must already be in the mac perimeter
 */
int
mac_mark_exclusive(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));
        /*
         * Look up its entry in the global hash table.
         */
        rw_enter(&i_mac_impl_lock, RW_WRITER);
        if (mip->mi_state_flags & MIS_DISABLED) {
                rw_exit(&i_mac_impl_lock);
                return (ENOENT);
        }

        /*
         * A reference to mac is held even if the link is not plumbed.
         * In i_dls_link_create() we open the MAC interface and hold the
         * reference. There is an additional reference for the mac_open
         * done in acquiring the mac perimeter
         */
        if (mip->mi_ref != 2) {
                rw_exit(&i_mac_impl_lock);
                return (EBUSY);
        }

        ASSERT(!(mip->mi_state_flags & MIS_EXCLUSIVE_HELD));
        mip->mi_state_flags |= MIS_EXCLUSIVE_HELD;
        rw_exit(&i_mac_impl_lock);
        return (0);
}

void
mac_unmark_exclusive(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        rw_enter(&i_mac_impl_lock, RW_WRITER);
        /* 1 for the creation and another for the perimeter */
        ASSERT(mip->mi_ref == 2 && (mip->mi_state_flags & MIS_EXCLUSIVE_HELD));
        mip->mi_state_flags &= ~MIS_EXCLUSIVE_HELD;
        rw_exit(&i_mac_impl_lock);
}

/*
 * Set the MTU for the specified MAC.
 */
int
mac_set_mtu(mac_handle_t mh, uint_t new_mtu, uint_t *old_mtu_arg)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        uint_t old_mtu;
        int rv = 0;

        i_mac_perim_enter(mip);

        if (!(mip->mi_callbacks->mc_callbacks & (MC_SETPROP|MC_GETPROP))) {
                rv = ENOTSUP;
                goto bail;
        }

        old_mtu = mip->mi_sdu_max;

        if (new_mtu == 0 || new_mtu < mip->mi_sdu_min) {
                rv = EINVAL;
                goto bail;
        }

        if (old_mtu != new_mtu) {
                rv = mip->mi_callbacks->mc_setprop(mip->mi_driver,
                    "mtu", MAC_PROP_MTU, sizeof (uint_t), &new_mtu);
                if (rv != 0)
                        goto bail;
                rv = mac_maxsdu_update(mh, new_mtu);
                ASSERT(rv == 0);
        }

bail:
        i_mac_perim_exit(mip);

        if (rv == 0 && old_mtu_arg != NULL)
                *old_mtu_arg = old_mtu;
        return (rv);
}

/*
 * Return the RX h/w information for the group indexed by grp_num.
 */
void
mac_get_hwrxgrp_info(mac_handle_t mh, int grp_index, uint_t *grp_num,
    uint_t *n_rings, uint_t *rings, uint_t *type, uint_t *n_clnts,
    char *clnts_name)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_grp_client_t *mcip;
        uint_t i = 0, index = 0;
        mac_ring_t      *ring;

        /* Revisit when we implement fully dynamic group allocation */
        ASSERT(grp_index >= 0 && grp_index < mip->mi_rx_group_count);

        rw_enter(&mip->mi_rw_lock, RW_READER);
        *grp_num = mip->mi_rx_groups[grp_index].mrg_index;
        *type = mip->mi_rx_groups[grp_index].mrg_type;
        *n_rings = mip->mi_rx_groups[grp_index].mrg_cur_count;
        ring = mip->mi_rx_groups[grp_index].mrg_rings;
        for (index = 0; index < mip->mi_rx_groups[grp_index].mrg_cur_count;
            index++) {
                rings[index] = ring->mr_index;
                ring = ring->mr_next;
        }
        /* Assuming the 1st is the default group */
        index = 0;
        if (grp_index == 0) {
                (void) strlcpy(clnts_name, "<default,mcast>,",
                    MAXCLIENTNAMELEN);
                index += strlen("<default,mcast>,");
        }
        for (mcip = mip->mi_rx_groups[grp_index].mrg_clients; mcip != NULL;
            mcip = mcip->mgc_next) {
                int name_len = strlen(mcip->mgc_client->mci_name);

                /*
                 * MAXCLIENTNAMELEN is the buffer size reserved for client
                 * names.
                 * XXXX Formating the client name string needs to be moved
                 * to user land when fixing the size of dhi_clnts in
                 * dld_hwgrpinfo_t. We should use n_clients * client_name for
                 * dhi_clntsin instead of MAXCLIENTNAMELEN
                 */
                if (index + name_len >= MAXCLIENTNAMELEN) {
                        index = MAXCLIENTNAMELEN;
                        break;
                }
                bcopy(mcip->mgc_client->mci_name, &(clnts_name[index]),
                    name_len);
                index += name_len;
                clnts_name[index++] = ',';
                i++;
        }

        /* Get rid of the last , */
        if (index > 0)
                clnts_name[index - 1] = '\0';
        *n_clnts = i;
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Return the TX h/w information for the group indexed by grp_num.
 */
void
mac_get_hwtxgrp_info(mac_handle_t mh, int grp_index, uint_t *grp_num,
    uint_t *n_rings, uint_t *rings, uint_t *type, uint_t *n_clnts,
    char *clnts_name)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_grp_client_t *mcip;
        uint_t i = 0, index = 0;
        mac_ring_t      *ring;

        /* Revisit when we implement fully dynamic group allocation */
        ASSERT(grp_index >= 0 && grp_index <= mip->mi_tx_group_count);

        rw_enter(&mip->mi_rw_lock, RW_READER);
        *grp_num = mip->mi_tx_groups[grp_index].mrg_index > 0 ?
            mip->mi_tx_groups[grp_index].mrg_index : grp_index;
        *type = mip->mi_tx_groups[grp_index].mrg_type;
        *n_rings = mip->mi_tx_groups[grp_index].mrg_cur_count;
        ring = mip->mi_tx_groups[grp_index].mrg_rings;
        for (index = 0; index < mip->mi_tx_groups[grp_index].mrg_cur_count;
            index++) {
                rings[index] = ring->mr_index;
                ring = ring->mr_next;
        }
        index = 0;
        /* Default group has an index of -1 */
        if (mip->mi_tx_groups[grp_index].mrg_index < 0) {
                (void) strlcpy(clnts_name, "<default>,",
                    MAXCLIENTNAMELEN);
                index += strlen("<default>,");
        }
        for (mcip = mip->mi_tx_groups[grp_index].mrg_clients; mcip != NULL;
            mcip = mcip->mgc_next) {
                int name_len = strlen(mcip->mgc_client->mci_name);

                /*
                 * MAXCLIENTNAMELEN is the buffer size reserved for client
                 * names.
                 * XXXX Formating the client name string needs to be moved
                 * to user land when fixing the size of dhi_clnts in
                 * dld_hwgrpinfo_t. We should use n_clients * client_name for
                 * dhi_clntsin instead of MAXCLIENTNAMELEN
                 */
                if (index + name_len >= MAXCLIENTNAMELEN) {
                        index = MAXCLIENTNAMELEN;
                        break;
                }
                bcopy(mcip->mgc_client->mci_name, &(clnts_name[index]),
                    name_len);
                index += name_len;
                clnts_name[index++] = ',';
                i++;
        }

        /* Get rid of the last , */
        if (index > 0)
                clnts_name[index - 1] = '\0';
        *n_clnts = i;
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Return the group count for RX or TX.
 */
uint_t
mac_hwgrp_num(mac_handle_t mh, int type)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        /*
         * Return the Rx and Tx group count; for the Tx we need to
         * include the default too.
         */
        return (type == MAC_RING_TYPE_RX ? mip->mi_rx_group_count :
            mip->mi_tx_groups != NULL ? mip->mi_tx_group_count + 1 : 0);
}

/*
 * The total number of free TX rings for this MAC.
 */
uint_t
mac_txavail_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_txrings_avail);
}

/*
 * The total number of free RX rings for this MAC.
 */
uint_t
mac_rxavail_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_rxrings_avail);
}

/*
 * The total number of reserved RX rings on this MAC.
 */
uint_t
mac_rxrsvd_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_rxrings_rsvd);
}

/*
 * The total number of reserved TX rings on this MAC.
 */
uint_t
mac_txrsvd_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_txrings_rsvd);
}

/*
 * Total number of free RX groups on this MAC.
 */
uint_t
mac_rxhwlnksavail_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_rxhwclnt_avail);
}

/*
 * Total number of RX groups reserved on this MAC.
 */
uint_t
mac_rxhwlnksrsvd_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_rxhwclnt_used);
}

/*
 * Total number of free TX groups on this MAC.
 */
uint_t
mac_txhwlnksavail_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_txhwclnt_avail);
}

/*
 * Total number of TX groups reserved on this MAC.
 */
uint_t
mac_txhwlnksrsvd_get(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        return (mip->mi_txhwclnt_used);
}

/*
 * Initialize the rings property for a mac client. A non-0 value for
 * rxring or txring specifies the number of rings required, a value
 * of MAC_RXRINGS_NONE/MAC_TXRINGS_NONE specifies that it doesn't need
 * any RX/TX rings and a value of MAC_RXRINGS_DONTCARE/MAC_TXRINGS_DONTCARE
 * means the system can decide whether it can give any rings or not.
 */
void
mac_client_set_rings(mac_client_handle_t mch, int rxrings, int txrings)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_resource_props_t    *mrp = MCIP_RESOURCE_PROPS(mcip);

        if (rxrings != MAC_RXRINGS_DONTCARE) {
                mrp->mrp_mask |= MRP_RX_RINGS;
                mrp->mrp_nrxrings = rxrings;
        }

        if (txrings != MAC_TXRINGS_DONTCARE) {
                mrp->mrp_mask |= MRP_TX_RINGS;
                mrp->mrp_ntxrings = txrings;
        }
}