/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright 2025 Oxide Computer Company
 */

/*
 * The softmac driver is used to "unify" non-GLDv3 drivers to the GLDv3
 * framework.  It also creates the kernel datalink structure for each
 * physical network device.
 *
 * Specifically, a softmac will be created for each physical network device
 * (dip) during the device's post-attach process.  When this softmac is
 * created, the following will also be done:
 *   - create the device's <link name, linkid> mapping;
 *   - register the mac if this is a non-GLDv3 device and the media type is
 *     supported by the GLDv3 framework;
 *   - create the kernel data-link structure for this physical device;
 *
 * This softmac will be destroyed during the device's pre-detach process,
 * and all the above will be undone.
 */

#include <sys/types.h>
#include <sys/file.h>
#include <sys/cred.h>
#include <sys/dlpi.h>
#include <sys/mac_provider.h>
#include <sys/disp.h>
#include <sys/sunndi.h>
#include <sys/modhash.h>
#include <sys/stropts.h>
#include <sys/sysmacros.h>
#include <sys/vlan.h>
#include <sys/softmac_impl.h>
#include <sys/softmac.h>
#include <sys/dls.h>

/* Used as a parameter to the mod hash walk of softmac structures */
typedef struct {
        softmac_t       *smw_softmac;
        boolean_t       smw_retry;
} softmac_walk_t;

/*
 * Softmac hash table including softmacs for both style-2 and style-1 devices.
 */
static krwlock_t        softmac_hash_lock;
static mod_hash_t       *softmac_hash;
static kmutex_t         smac_global_lock;
static kcondvar_t       smac_global_cv;

static kmem_cache_t     *softmac_cachep;

#define SOFTMAC_HASHSZ          64

static void softmac_create_task(void *);
static void softmac_mac_register(softmac_t *);
static int softmac_create_datalink(softmac_t *);
static int softmac_m_start(void *);
static void softmac_m_stop(void *);
static int softmac_m_open(void *);
static void softmac_m_close(void *);
static boolean_t softmac_m_getcapab(void *, mac_capab_t, void *);
static int softmac_m_setprop(void *, const char *, mac_prop_id_t,
    uint_t, const void *);
static int softmac_m_getprop(void *, const char *, mac_prop_id_t,
    uint_t, void *);
static void softmac_m_propinfo(void *, const char *, mac_prop_id_t,
    mac_prop_info_handle_t);

#define SOFTMAC_M_CALLBACK_FLAGS        \
        (MC_IOCTL | MC_GETCAPAB | MC_OPEN | MC_CLOSE | MC_SETPROP | \
        MC_GETPROP | MC_PROPINFO)

static mac_callbacks_t softmac_m_callbacks = {
        SOFTMAC_M_CALLBACK_FLAGS,
        softmac_m_stat,
        softmac_m_start,
        softmac_m_stop,
        softmac_m_promisc,
        softmac_m_multicst,
        softmac_m_unicst,
        softmac_m_tx,
        NULL,
        softmac_m_ioctl,
        softmac_m_getcapab,
        softmac_m_open,
        softmac_m_close,
        softmac_m_setprop,
        softmac_m_getprop,
        softmac_m_propinfo
};

/*ARGSUSED*/
static int
softmac_constructor(void *buf, void *arg, int kmflag)
{
        softmac_t       *softmac = buf;

        bzero(buf, sizeof (softmac_t));
        mutex_init(&softmac->smac_mutex, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&softmac->smac_active_mutex, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&softmac->smac_fp_mutex, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&softmac->smac_cv, NULL, CV_DEFAULT, NULL);
        cv_init(&softmac->smac_fp_cv, NULL, CV_DEFAULT, NULL);
        list_create(&softmac->smac_sup_list, sizeof (softmac_upper_t),
            offsetof(softmac_upper_t, su_list_node));
        return (0);
}

/*ARGSUSED*/
static void
softmac_destructor(void *buf, void *arg)
{
        softmac_t       *softmac = buf;

        ASSERT(softmac->smac_fp_disable_clients == 0);
        ASSERT(!softmac->smac_fastpath_admin_disabled);

        ASSERT(!(softmac->smac_flags & SOFTMAC_ATTACH_DONE));
        ASSERT(softmac->smac_hold_cnt == 0);
        ASSERT(softmac->smac_attachok_cnt == 0);
        ASSERT(softmac->smac_mh == NULL);
        ASSERT(softmac->smac_softmac[0] == NULL &&
            softmac->smac_softmac[1] == NULL);
        ASSERT(softmac->smac_lower == NULL);
        ASSERT(softmac->smac_active == B_FALSE);
        ASSERT(softmac->smac_nactive == 0);
        ASSERT(list_is_empty(&softmac->smac_sup_list));

        list_destroy(&softmac->smac_sup_list);
        mutex_destroy(&softmac->smac_mutex);
        mutex_destroy(&softmac->smac_active_mutex);
        mutex_destroy(&softmac->smac_fp_mutex);
        cv_destroy(&softmac->smac_cv);
        cv_destroy(&softmac->smac_fp_cv);
}

void
softmac_init()
{
        softmac_hash = mod_hash_create_extended("softmac_hash",
            SOFTMAC_HASHSZ, mod_hash_null_keydtor, mod_hash_null_valdtor,
            mod_hash_bystr, NULL, mod_hash_strkey_cmp, KM_SLEEP);

        rw_init(&softmac_hash_lock, NULL, RW_DEFAULT, NULL);
        mutex_init(&smac_global_lock, NULL, MUTEX_DRIVER, NULL);
        cv_init(&smac_global_cv, NULL, CV_DRIVER, NULL);

        softmac_cachep = kmem_cache_create("softmac_cache",
            sizeof (softmac_t), 0, softmac_constructor,
            softmac_destructor, NULL, NULL, NULL, 0);
        ASSERT(softmac_cachep != NULL);
        softmac_fp_init();
}

void
softmac_fini()
{
        softmac_fp_fini();
        kmem_cache_destroy(softmac_cachep);
        rw_destroy(&softmac_hash_lock);
        mod_hash_destroy_hash(softmac_hash);
        mutex_destroy(&smac_global_lock);
        cv_destroy(&smac_global_cv);
}

/* ARGSUSED */
static uint_t
softmac_exist(mod_hash_key_t key, mod_hash_val_t *val, void *arg)
{
        boolean_t *pexist = arg;

        *pexist = B_TRUE;
        return (MH_WALK_TERMINATE);
}

boolean_t
softmac_busy()
{
        boolean_t exist = B_FALSE;

        rw_enter(&softmac_hash_lock, RW_READER);
        mod_hash_walk(softmac_hash, softmac_exist, &exist);
        rw_exit(&softmac_hash_lock);
        return (exist);
}

/*
 *
 * softmac_create() is called for each minor node during the post-attach of
 * each DDI_NT_NET device instance.  Note that it is possible that a device
 * instance has two minor nodes (DLPI style-1 and style-2), so that for that
 * specific device, softmac_create() could be called twice.
 *
 * A softmac_t is used to track each DDI_NT_NET device, and a softmac_dev_t
 * is created to track each minor node.
 *
 * For each minor node of a legacy device, a taskq is started to finish
 * softmac_mac_register(), which will finish the rest of work (see comments
 * above softmac_mac_register()).
 *
 *                      softmac state machine
 * --------------------------------------------------------------------------
 * OLD STATE            EVENT                                   NEW STATE
 * --------------------------------------------------------------------------
 * UNINIT               attach of 1st minor node                ATTACH_INPROG
 * okcnt = 0            net_postattach -> softmac_create        okcnt = 1
 *
 * ATTACH_INPROG        attach of 2nd minor node (GLDv3)        ATTACH_DONE
 * okcnt = 1            net_postattach -> softmac_create        okcnt = 2
 *
 * ATTACH_INPROG        attach of 2nd minor node (legacy)       ATTACH_INPROG
 * okcnt = 1            net_postattach -> softmac_create        okcnt = 2
 *                      schedule softmac_mac_register
 *
 * ATTACH_INPROG        legacy device node                      ATTACH_DONE
 * okcnt = 2            softmac_mac_register                    okcnt = 2
 *
 * ATTACH_DONE          detach of 1st minor node                DETACH_INPROG
 * okcnt = 2            (success)                               okcnt = 1
 *
 * DETACH_INPROG        detach of 2nd minor node                UNINIT (or free)
 * okcnt = 1            (success)                               okcnt = 0
 *
 * ATTACH_DONE          detach failure                          state unchanged
 * DETACH_INPROG                                                left = okcnt
 *
 * DETACH_INPROG        reattach                                ATTACH_INPROG
 * okcnt = 0,1          net_postattach -> softmac_create
 *
 * ATTACH_DONE          reattach                                ATTACH_DONE
 * left != 0            net_postattach -> softmac_create        left = 0
 *
 * Abbreviation notes:
 * states have SOFTMAC_ prefix,
 * okcnt - softmac_attach_okcnt,
 * left - softmac_attached_left
 */

#ifdef DEBUG
void
softmac_state_verify(softmac_t *softmac)
{
        ASSERT(MUTEX_HELD(&softmac->smac_mutex));

        /*
         * There are at most 2 minor nodes, one per DLPI style
         */
        ASSERT(softmac->smac_cnt <= 2 && softmac->smac_attachok_cnt <= 2);

        /*
         * The smac_attachok_cnt represents the number of attaches i.e. the
         * number of times net_postattach -> softmac_create() has been called
         * for a device instance.
         */
        ASSERT(softmac->smac_attachok_cnt == SMAC_NONZERO_NODECNT(softmac));

        /*
         * softmac_create (or softmac_mac_register) ->  softmac_create_datalink
         * happens only after all minor nodes have been attached
         */
        ASSERT(softmac->smac_state != SOFTMAC_ATTACH_DONE ||
            softmac->smac_attachok_cnt == softmac->smac_cnt);

        if (softmac->smac_attachok_cnt == 0) {
                ASSERT(softmac->smac_state == SOFTMAC_UNINIT);
                ASSERT(softmac->smac_mh == NULL);
        } else if (softmac->smac_attachok_cnt < softmac->smac_cnt) {
                ASSERT(softmac->smac_state == SOFTMAC_ATTACH_INPROG ||
                    softmac->smac_state == SOFTMAC_DETACH_INPROG);
                ASSERT(softmac->smac_mh == NULL);
        } else {
                /*
                 * In the stable condition the state whould be
                 * SOFTMAC_ATTACH_DONE. But there is a small transient window
                 * in softmac_destroy where we change the state to
                 * SOFTMAC_DETACH_INPROG and drop the lock before doing
                 * the link destroy
                 */
                ASSERT(softmac->smac_attachok_cnt == softmac->smac_cnt);
                ASSERT(softmac->smac_state != SOFTMAC_UNINIT);
        }
        if (softmac->smac_mh != NULL)
                ASSERT(softmac->smac_attachok_cnt == softmac->smac_cnt);
}
#endif

#ifdef DEBUG
#define SOFTMAC_STATE_VERIFY(softmac)   softmac_state_verify(softmac)
#else
#define SOFTMAC_STATE_VERIFY(softmac)
#endif

int
softmac_create(dev_info_t *dip, dev_t dev)
{
        char            devname[MAXNAMELEN];
        softmac_t       *softmac;
        softmac_dev_t   *softmac_dev = NULL;
        int             index;
        int             ppa, err = 0;

        /*
         * Force the softmac driver to be attached.
         */
        if (i_ddi_attach_pseudo_node(SOFTMAC_DEV_NAME) == NULL) {
                cmn_err(CE_WARN, "softmac_create:softmac attach fails");
                return (ENXIO);
        }

        if (GLDV3_DRV(ddi_driver_major(dip))) {
                minor_t minor = getminor(dev);
                /*
                 * For GLDv3, we don't care about the DLPI style 2
                 * compatibility node.  (We know that all such devices
                 * have style 1 nodes.)
                 */
                if ((strcmp(ddi_driver_name(dip), "clone") == 0) ||
                    (getmajor(dev) == ddi_name_to_major("clone")) ||
                    (minor == 0)) {
                        return (0);
                }

                /*
                 * Likewise, we know that the minor number for DLPI style 1
                 * nodes is constrained to a maximum value.
                 */
                if (minor >= DLS_MAX_MINOR) {
                        return (ENOTSUP);
                }
                /*
                 * Otherwise we can decode the instance from the minor number,
                 * which allows for situations with multiple mac instances
                 * for a single dev_info_t.
                 */
                ppa = DLS_MINOR2INST(minor);
        } else {
                /*
                 * For legacy drivers, we just have to limit them to
                 * two minor nodes, one style 1 and one style 2, and
                 * we assume the ddi_get_instance() is the PPA.
                 * Drivers that need more flexibility should be ported
                 * to GLDv3.
                 */
                ppa = ddi_get_instance(dip);
                if (i_ddi_minor_node_count(dip, DDI_NT_NET) > 2) {
                        cmn_err(CE_WARN, "%s has more than 2 minor nodes; "
                            "unsupported", devname);
                        return (ENOTSUP);
                }
        }

        (void) snprintf(devname, MAXNAMELEN, "%s%d", ddi_driver_name(dip), ppa);

        /*
         * Check whether the softmac for the specified device already exists
         */
        rw_enter(&softmac_hash_lock, RW_WRITER);
        if ((mod_hash_find(softmac_hash, (mod_hash_key_t)devname,
            (mod_hash_val_t *)&softmac)) != 0) {

                softmac = kmem_cache_alloc(softmac_cachep, KM_SLEEP);
                (void) strlcpy(softmac->smac_devname, devname, MAXNAMELEN);

                err = mod_hash_insert(softmac_hash,
                    (mod_hash_key_t)softmac->smac_devname,
                    (mod_hash_val_t)softmac);
                ASSERT(err == 0);
                mutex_enter(&smac_global_lock);
                cv_broadcast(&smac_global_cv);
                mutex_exit(&smac_global_lock);
        }

        mutex_enter(&softmac->smac_mutex);
        SOFTMAC_STATE_VERIFY(softmac);
        if (softmac->smac_state != SOFTMAC_ATTACH_DONE)
                softmac->smac_state = SOFTMAC_ATTACH_INPROG;
        if (softmac->smac_attachok_cnt == 0) {
                /*
                 * Initialize the softmac if this is the post-attach of the
                 * first minor node.
                 */
                softmac->smac_flags = 0;
                softmac->smac_umajor = ddi_driver_major(dip);
                softmac->smac_uppa = ppa;

                /*
                 * For GLDv3, we ignore the style 2 node (see the logic
                 * above on that), and we should have exactly one attach
                 * per MAC instance (possibly more than one per dev_info_t).
                 */
                if (GLDV3_DRV(ddi_driver_major(dip))) {
                        softmac->smac_flags |= SOFTMAC_GLDV3;
                        softmac->smac_cnt = 1;
                } else {
                        softmac->smac_cnt =
                            i_ddi_minor_node_count(dip, DDI_NT_NET);
                }
        }

        index = (getmajor(dev) == ddi_name_to_major("clone"));
        if (softmac->smac_softmac[index] != NULL) {
                /*
                 * This is possible if the post_attach() is called after
                 * pre_detach() fails. This seems to be a defect of the DACF
                 * framework. We work around it by using a smac_attached_left
                 * field that tracks this
                 */
                ASSERT(softmac->smac_attached_left != 0);
                softmac->smac_attached_left--;
                mutex_exit(&softmac->smac_mutex);
                rw_exit(&softmac_hash_lock);
                return (0);

        }
        mutex_exit(&softmac->smac_mutex);
        rw_exit(&softmac_hash_lock);

        softmac_dev = kmem_zalloc(sizeof (softmac_dev_t), KM_SLEEP);
        softmac_dev->sd_dev = dev;

        mutex_enter(&softmac->smac_mutex);
        softmac->smac_softmac[index] = softmac_dev;
        /*
         * Continue to register the mac and create the datalink only when all
         * the minor nodes are attached.
         */
        if (++softmac->smac_attachok_cnt != softmac->smac_cnt) {
                mutex_exit(&softmac->smac_mutex);
                return (0);
        }

        /*
         * All of the minor nodes have been attached; start a taskq
         * to do the rest of the work.  We use a taskq instead of
         * doing the work here because:
         *
         * We could be called as a result of a open() system call
         * where spec_open() already SLOCKED the snode. Using a taskq
         * sidesteps the risk that our ldi_open_by_dev() call would
         * deadlock trying to set SLOCKED on the snode again.
         *
         * The devfs design requires that the downcalls don't use any
         * interruptible cv_wait which happens when we do door upcalls.
         * Otherwise the downcalls which may be holding devfs resources
         * may cause a deadlock if the thread is stopped. Also we need to make
         * sure these downcalls into softmac_create or softmac_destroy
         * don't cv_wait on any devfs related condition. Thus softmac_destroy
         * returns EBUSY if the asynchronous threads started in softmac_create
         * haven't finished.
         */
        (void) taskq_dispatch(system_taskq, softmac_create_task,
            softmac, TQ_SLEEP);
        mutex_exit(&softmac->smac_mutex);
        return (0);
}

static boolean_t
softmac_m_getcapab(void *arg, mac_capab_t cap, void *cap_data)
{
        softmac_t *softmac = arg;

        if (!(softmac->smac_capab_flags & cap))
                return (B_FALSE);

        switch (cap) {
        case MAC_CAPAB_HCKSUM: {
                uint32_t *txflags = cap_data;

                *txflags = softmac->smac_hcksum_txflags;
                break;
        }
        case MAC_CAPAB_LEGACY: {
                mac_capab_legacy_t *legacy = cap_data;

                /*
                 * The caller is not interested in the details.
                 */
                if (legacy == NULL)
                        break;

                legacy->ml_unsup_note = ~softmac->smac_notifications &
                    (DL_NOTE_LINK_UP | DL_NOTE_LINK_DOWN | DL_NOTE_SPEED);
                legacy->ml_active_set = softmac_active_set;
                legacy->ml_active_clear = softmac_active_clear;
                legacy->ml_fastpath_disable = softmac_fastpath_disable;
                legacy->ml_fastpath_enable = softmac_fastpath_enable;
                legacy->ml_dev = makedevice(softmac->smac_umajor,
                    softmac->smac_uppa + 1);
                break;
        }

        /*
         * For the capabilities below, there's nothing for us to fill in;
         * simply return B_TRUE if we support it.
         */
        case MAC_CAPAB_NO_ZCOPY:
        case MAC_CAPAB_NO_NATIVEVLAN:
        default:
                break;
        }
        return (B_TRUE);
}

static int
softmac_update_info(softmac_t *softmac, datalink_id_t *linkidp)
{
        datalink_id_t   linkid = DATALINK_INVALID_LINKID;
        uint32_t        media;
        int             err;

        if ((err = dls_mgmt_update(softmac->smac_devname, softmac->smac_media,
            softmac->smac_flags & SOFTMAC_NOSUPP, &media, &linkid)) == 0) {
                *linkidp = linkid;
        }

        if (err == EEXIST) {
                /*
                 * There is a link name conflict.  Either:
                 *
                 * - An existing link with the same device name with a
                 *   different media type from of the given type.
                 *   Mark this link back to persistent only; or
                 *
                 * - We cannot assign the "suggested" name because
                 *   GLDv3 and therefore vanity naming is not supported
                 *   for this link type. Delete this link's <link name,
                 *   linkid> mapping.
                 */
                if (media != softmac->smac_media) {
                        cmn_err(CE_WARN, "%s device %s conflicts with "
                            "existing %s device %s.",
                            dl_mactypestr(softmac->smac_media),
                            softmac->smac_devname, dl_mactypestr(media),
                            softmac->smac_devname);
                        (void) dls_mgmt_destroy(linkid, B_FALSE);
                } else {
                        cmn_err(CE_WARN, "link name %s is already in-use.",
                            softmac->smac_devname);
                        (void) dls_mgmt_destroy(linkid, B_TRUE);
                }

                cmn_err(CE_WARN, "%s device might not be available "
                    "for use.", softmac->smac_devname);
                cmn_err(CE_WARN, "See dladm(8) for more information.");
        }

        return (err);
}

/*
 * This function:
 * 1. provides the link's media type to dlmgmtd.
 * 2. creates the GLDv3 datalink if the media type is supported by GLDv3.
 */
static int
softmac_create_datalink(softmac_t *softmac)
{
        datalink_id_t   linkid = DATALINK_INVALID_LINKID;
        int             err;

        /*
         * Inform dlmgmtd of this link so that softmac_hold_device() is able
         * to know the existence of this link. If this failed with EBADF,
         * it might be because dlmgmtd was not started in time (e.g.,
         * diskless boot); ignore the failure and continue to create
         * the GLDv3 datalink if needed.
         */
        err = dls_mgmt_create(softmac->smac_devname,
            makedevice(softmac->smac_umajor, softmac->smac_uppa + 1),
            DATALINK_CLASS_PHYS, DL_OTHER, B_TRUE, &linkid);
        if (err != 0 && err != EBADF)
                return (err);

        /*
         * Provide the media type of the physical link to dlmgmtd.
         */
        if ((err != EBADF) &&
            ((err = softmac_update_info(softmac, &linkid)) != 0)) {
                return (err);
        }

        /*
         * Create the GLDv3 datalink.
         */
        if (!(softmac->smac_flags & SOFTMAC_NOSUPP)) {
                err = dls_devnet_create(softmac->smac_mh, linkid,
                    crgetzoneid(CRED()));
                if (err != 0) {
                        cmn_err(CE_WARN, "dls_devnet_create failed for %s",
                            softmac->smac_devname);
                        return (err);
                }
        }

        if (linkid == DATALINK_INVALID_LINKID) {
                mutex_enter(&softmac->smac_mutex);
                softmac->smac_flags |= SOFTMAC_NEED_RECREATE;
                mutex_exit(&softmac->smac_mutex);
        }

        return (0);
}

static void
softmac_create_task(void *arg)
{
        softmac_t       *softmac = arg;
        mac_handle_t    mh;
        int             err;

        if (!GLDV3_DRV(softmac->smac_umajor)) {
                softmac_mac_register(softmac);
                return;
        }

        if ((err = mac_open(softmac->smac_devname, &mh)) != 0)
                goto done;

        mutex_enter(&softmac->smac_mutex);
        softmac->smac_media = (mac_info(mh))->mi_nativemedia;
        softmac->smac_mh = mh;
        mutex_exit(&softmac->smac_mutex);

        /*
         * We can safely release the reference on the mac because
         * this mac will only be unregistered and destroyed when
         * the device detaches, and the softmac will be destroyed
         * before then (in the pre-detach routine of the device).
         */
        mac_close(mh);

        /*
         * Create the GLDv3 datalink for this mac.
         */
        err = softmac_create_datalink(softmac);

done:
        mutex_enter(&softmac->smac_mutex);
        if (err != 0)
                softmac->smac_mh = NULL;
        softmac->smac_attacherr = err;
        softmac->smac_state = SOFTMAC_ATTACH_DONE;
        cv_broadcast(&softmac->smac_cv);
        mutex_exit(&softmac->smac_mutex);
}

/*
 * This function is only called for legacy devices. It:
 * 1. registers the MAC for the legacy devices whose media type is supported
 *    by the GLDv3 framework.
 * 2. creates the GLDv3 datalink if the media type is supported by GLDv3.
 */
static void
softmac_mac_register(softmac_t *softmac)
{
        softmac_dev_t   *softmac_dev;
        dev_t           dev;
        ldi_handle_t    lh = NULL;
        ldi_ident_t     li = NULL;
        int             index;
        boolean_t       native_vlan = B_FALSE;
        int             err;

        /*
         * Note that we do not need any locks to access this softmac pointer,
         * as softmac_destroy() will wait until this function is called.
         */
        ASSERT(softmac != NULL);
        ASSERT(softmac->smac_state == SOFTMAC_ATTACH_INPROG &&
            softmac->smac_attachok_cnt == softmac->smac_cnt);

        if ((err = ldi_ident_from_dip(softmac_dip, &li)) != 0) {
                mutex_enter(&softmac->smac_mutex);
                goto done;
        }

        /*
         * Determine whether this legacy device support VLANs by opening
         * the style-2 device node (if it exists) and attaching to a VLAN
         * PPA (1000 + ppa).
         */
        dev = makedevice(ddi_name_to_major("clone"), softmac->smac_umajor);
        err = ldi_open_by_dev(&dev, OTYP_CHR, FREAD|FWRITE, kcred, &lh, li);
        if (err == 0) {
                if (dl_attach(lh, softmac->smac_uppa + 1 * 1000, NULL) == 0)
                        native_vlan = B_TRUE;
                (void) ldi_close(lh, FREAD|FWRITE, kcred);
        }

        err = EINVAL;
        for (index = 0; index < 2; index++) {
                dl_info_ack_t   dlia;
                dl_error_ack_t  dlea;
                uint32_t        notes;
                struct strioctl iocb;
                uint32_t        margin;
                int             rval;

                if ((softmac_dev = softmac->smac_softmac[index]) == NULL)
                        continue;

                softmac->smac_dev = dev = softmac_dev->sd_dev;
                if (ldi_open_by_dev(&dev, OTYP_CHR, FREAD|FWRITE, kcred, &lh,
                    li) != 0) {
                        continue;
                }

                /*
                 * Pop all the intermediate modules in order to negotiate
                 * capabilities correctly.
                 */
                while (ldi_ioctl(lh, I_POP, 0, FKIOCTL, kcred, &rval) == 0)
                        ;

                /* DLPI style-1 or DLPI style-2? */
                if ((rval = dl_info(lh, &dlia, NULL, NULL, &dlea)) != 0) {
                        if (rval == ENOTSUP) {
                                cmn_err(CE_NOTE, "softmac: received "
                                    "DL_ERROR_ACK to DL_INFO_ACK; "
                                    "DLPI errno 0x%x, UNIX errno %d",
                                    dlea.dl_errno, dlea.dl_unix_errno);
                        }
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        continue;
                }

                /*
                 * Currently only DL_ETHER has GLDv3 mac plugin support.
                 * For media types that GLDv3 does not support, create a
                 * link id for it.
                 */
                if ((softmac->smac_media = dlia.dl_mac_type) != DL_ETHER) {
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        err = 0;
                        break;
                }

                if ((dlia.dl_provider_style == DL_STYLE2) &&
                    (dl_attach(lh, softmac->smac_uppa, NULL) != 0)) {
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        continue;
                }

                if ((rval = dl_bind(lh, 0, NULL)) != 0) {
                        if (rval == ENOTSUP) {
                                cmn_err(CE_NOTE, "softmac: received "
                                    "DL_ERROR_ACK to DL_BIND_ACK; "
                                    "DLPI errno 0x%x, UNIX errno %d",
                                    dlea.dl_errno, dlea.dl_unix_errno);
                        }
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        continue;
                }

                /*
                 * Call dl_info() after dl_bind() because some drivers only
                 * provide correct information (e.g. MAC address) once bound.
                 */
                softmac->smac_addrlen = sizeof (softmac->smac_unicst_addr);
                if ((rval = dl_info(lh, &dlia, softmac->smac_unicst_addr,
                    &softmac->smac_addrlen, &dlea)) != 0) {
                        if (rval == ENOTSUP) {
                                cmn_err(CE_NOTE, "softmac: received "
                                    "DL_ERROR_ACK to DL_INFO_ACK; "
                                    "DLPI errno 0x%x, UNIX errno %d",
                                    dlea.dl_errno, dlea.dl_unix_errno);
                        }
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        continue;
                }

                softmac->smac_style = dlia.dl_provider_style;
                softmac->smac_saplen = ABS(dlia.dl_sap_length);
                softmac->smac_min_sdu = dlia.dl_min_sdu;
                softmac->smac_max_sdu = dlia.dl_max_sdu;

                if ((softmac->smac_saplen != sizeof (uint16_t)) ||
                    (softmac->smac_addrlen != ETHERADDRL) ||
                    (dlia.dl_brdcst_addr_length != ETHERADDRL) ||
                    (dlia.dl_brdcst_addr_offset == 0)) {
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        continue;
                }

                /*
                 * Check other DLPI capabilities. Note that this must be after
                 * dl_bind() because some drivers return DL_ERROR_ACK if the
                 * stream is not bound. It is also before mac_register(), so
                 * we don't need any lock protection here.
                 */
                softmac->smac_capab_flags =
                    (MAC_CAPAB_NO_ZCOPY | MAC_CAPAB_LEGACY);

                softmac->smac_no_capability_req = B_FALSE;
                if (softmac_fill_capab(lh, softmac) != 0)
                        softmac->smac_no_capability_req = B_TRUE;

                /*
                 * Check the margin of the underlying driver.
                 */
                margin = 0;
                iocb.ic_cmd = DLIOCMARGININFO;
                iocb.ic_timout = INFTIM;
                iocb.ic_len = sizeof (margin);
                iocb.ic_dp = (char *)&margin;
                softmac->smac_margin = 0;

                if (ldi_ioctl(lh, I_STR, (intptr_t)&iocb, FKIOCTL, kcred,
                    &rval) == 0) {
                        softmac->smac_margin = margin;
                }

                /*
                 * If the legacy driver doesn't support DLIOCMARGININFO, but
                 * it can support native VLAN, correct its margin value to 4.
                 */
                if (native_vlan) {
                        if (softmac->smac_margin == 0)
                                softmac->smac_margin = VLAN_TAGSZ;
                } else {
                        softmac->smac_capab_flags |= MAC_CAPAB_NO_NATIVEVLAN;
                }

                /*
                 * Not all drivers support DL_NOTIFY_REQ, so ignore ENOTSUP.
                 */
                softmac->smac_notifications = 0;
                notes = DL_NOTE_PHYS_ADDR | DL_NOTE_LINK_UP | DL_NOTE_LINK_DOWN;
                switch (dl_notify(lh, &notes, NULL)) {
                case 0:
                        softmac->smac_notifications = notes;
                        break;
                case ENOTSUP:
                        break;
                default:
                        (void) ldi_close(lh, FREAD|FWRITE, kcred);
                        continue;
                }

                (void) ldi_close(lh, FREAD|FWRITE, kcred);
                err = 0;
                break;
        }
        ldi_ident_release(li);

        mutex_enter(&softmac->smac_mutex);

        if (err != 0)
                goto done;

        if (softmac->smac_media != DL_ETHER)
                softmac->smac_flags |= SOFTMAC_NOSUPP;

        /*
         * Finally, we're ready to register ourselves with the MAC layer
         * interface; if this succeeds, we're all ready to start()
         */
        if (!(softmac->smac_flags & SOFTMAC_NOSUPP)) {
                mac_register_t  *macp;

                if ((macp = mac_alloc(MAC_VERSION)) == NULL) {
                        err = ENOMEM;
                        goto done;
                }

                macp->m_type_ident = MAC_PLUGIN_IDENT_ETHER;
                macp->m_driver = softmac;
                macp->m_dip = softmac_dip;

                macp->m_margin = softmac->smac_margin;
                macp->m_src_addr = softmac->smac_unicst_addr;
                macp->m_min_sdu = softmac->smac_min_sdu;
                macp->m_max_sdu = softmac->smac_max_sdu;
                macp->m_callbacks = &softmac_m_callbacks;
                macp->m_instance = (uint_t)-1;

                err = mac_register(macp, &softmac->smac_mh);
                mac_free(macp);
                if (err != 0) {
                        cmn_err(CE_WARN, "mac_register failed for %s",
                            softmac->smac_devname);
                        goto done;
                }
        }
        mutex_exit(&softmac->smac_mutex);

        /*
         * Try to create the datalink for this softmac.
         */
        if ((err = softmac_create_datalink(softmac)) != 0) {
                if (!(softmac->smac_flags & SOFTMAC_NOSUPP))
                        (void) mac_unregister(softmac->smac_mh);
                mutex_enter(&softmac->smac_mutex);
                softmac->smac_mh = NULL;
                goto done;
        }
        /*
         * If succeed, create the thread which handles the DL_NOTIFY_IND from
         * the lower stream.
         */
        mutex_enter(&softmac->smac_mutex);
        if (softmac->smac_mh != NULL) {
                softmac->smac_notify_thread = thread_create(NULL, 0,
                    softmac_notify_thread, softmac, 0, &p0,
                    TS_RUN, minclsyspri);
        }

done:
        ASSERT(softmac->smac_state == SOFTMAC_ATTACH_INPROG &&
            softmac->smac_attachok_cnt == softmac->smac_cnt);
        softmac->smac_state = SOFTMAC_ATTACH_DONE;
        softmac->smac_attacherr = err;
        cv_broadcast(&softmac->smac_cv);
        mutex_exit(&softmac->smac_mutex);
}

int
softmac_destroy(dev_info_t *dip, dev_t dev)
{
        char                    devname[MAXNAMELEN];
        softmac_t               *softmac;
        softmac_dev_t           *softmac_dev;
        int                     index;
        int                     ppa, err;
        datalink_id_t           linkid;
        mac_handle_t            smac_mh;
        uint32_t                smac_flags;

        if (GLDV3_DRV(ddi_driver_major(dip))) {
                minor_t minor = getminor(dev);
                /*
                 * For an explanation of this logic, see the
                 * equivalent code in softmac_create.
                 */
                if ((strcmp(ddi_driver_name(dip), "clone") == 0) ||
                    (getmajor(dev) == ddi_name_to_major("clone")) ||
                    (minor == 0)) {
                        return (0);
                }
                if (minor >= DLS_MAX_MINOR) {
                        return (ENOTSUP);
                }
                ppa = DLS_MINOR2INST(minor);
        } else {
                ppa = ddi_get_instance(dip);
        }

        (void) snprintf(devname, MAXNAMELEN, "%s%d", ddi_driver_name(dip), ppa);

        /*
         * We are called only from the predetach entry point. The DACF
         * framework ensures there can't be a concurrent postattach call
         * for the same softmac. The softmac found out from the modhash
         * below can't vanish beneath us since this is the only place where
         * it is deleted.
         */
        err = mod_hash_find(softmac_hash, (mod_hash_key_t)devname,
            (mod_hash_val_t *)&softmac);
        ASSERT(err == 0);

        mutex_enter(&softmac->smac_mutex);
        SOFTMAC_STATE_VERIFY(softmac);

        /*
         * Fail the predetach routine if this softmac is in-use.
         * Make sure these downcalls into softmac_create or softmac_destroy
         * don't cv_wait on any devfs related condition. Thus softmac_destroy
         * returns EBUSY if the asynchronous thread started in softmac_create
         * hasn't finished
         */
        if ((softmac->smac_hold_cnt != 0) ||
            (softmac->smac_state == SOFTMAC_ATTACH_INPROG)) {
                softmac->smac_attached_left = softmac->smac_attachok_cnt;
                mutex_exit(&softmac->smac_mutex);
                return (EBUSY);
        }

        /*
         * Even if the predetach of one minor node has already failed
         * (smac_attached_left is not 0), the DACF framework will continue
         * to call the predetach routines of the other minor nodes,
         * so we fail these calls here.
         */
        if (softmac->smac_attached_left != 0) {
                mutex_exit(&softmac->smac_mutex);
                return (EBUSY);
        }

        smac_mh = softmac->smac_mh;
        smac_flags = softmac->smac_flags;
        softmac->smac_state = SOFTMAC_DETACH_INPROG;
        mutex_exit(&softmac->smac_mutex);

        if (smac_mh != NULL) {
                /*
                 * This is the first minor node that is being detached for this
                 * softmac.
                 */
                ASSERT(softmac->smac_attachok_cnt == softmac->smac_cnt);
                if (!(smac_flags & SOFTMAC_NOSUPP)) {
                        if ((err = dls_devnet_destroy(smac_mh, &linkid,
                            B_FALSE)) != 0) {
                                goto error;
                        }
                }
                /*
                 * If softmac_mac_register() succeeds in registering the mac
                 * of the legacy device, unregister it.
                 */
                if (!(smac_flags & (SOFTMAC_GLDV3 | SOFTMAC_NOSUPP))) {
                        if ((err = mac_disable_nowait(smac_mh)) != 0) {
                                (void) dls_devnet_create(smac_mh, linkid,
                                    crgetzoneid(CRED()));
                                goto error;
                        }
                        /*
                         * Ask softmac_notify_thread to quit, and wait for
                         * that to be done.
                         */
                        mutex_enter(&softmac->smac_mutex);
                        softmac->smac_flags |= SOFTMAC_NOTIFY_QUIT;
                        cv_broadcast(&softmac->smac_cv);
                        while (
                            (softmac->smac_flags & SOFTMAC_NOTIFY_DONE) == 0) {
                                cv_wait(&softmac->smac_cv,
                                    &softmac->smac_mutex);
                        }
                        thread_join(softmac->smac_notify_thread->t_did);
                        softmac->smac_notify_thread = NULL;
                        mutex_exit(&softmac->smac_mutex);
                        VERIFY(mac_unregister(smac_mh) == 0);
                }
                softmac->smac_mh = NULL;
        }

        /*
         * Free softmac_dev
         */
        rw_enter(&softmac_hash_lock, RW_WRITER);
        mutex_enter(&softmac->smac_mutex);

        ASSERT(softmac->smac_state == SOFTMAC_DETACH_INPROG &&
            softmac->smac_attachok_cnt != 0);
        softmac->smac_mh = NULL;
        index = (getmajor(dev) == ddi_name_to_major("clone"));
        softmac_dev = softmac->smac_softmac[index];
        ASSERT(softmac_dev != NULL);
        softmac->smac_softmac[index] = NULL;
        kmem_free(softmac_dev, sizeof (softmac_dev_t));

        if (--softmac->smac_attachok_cnt == 0) {
                mod_hash_val_t  hashval;

                softmac->smac_state = SOFTMAC_UNINIT;
                if (softmac->smac_hold_cnt != 0) {
                        /*
                         * Someone did a softmac_hold_device while we dropped
                         * the locks. Leave the softmac itself intact which
                         * will be reused by the reattach
                         */
                        mutex_exit(&softmac->smac_mutex);
                        rw_exit(&softmac_hash_lock);
                        return (0);
                }
                err = mod_hash_remove(softmac_hash,
                    (mod_hash_key_t)devname,
                    (mod_hash_val_t *)&hashval);
                ASSERT(err == 0);

                mutex_exit(&softmac->smac_mutex);
                rw_exit(&softmac_hash_lock);
                ASSERT(softmac->smac_fp_disable_clients == 0);
                softmac->smac_fastpath_admin_disabled = B_FALSE;
                kmem_cache_free(softmac_cachep, softmac);
                return (0);
        }
        mutex_exit(&softmac->smac_mutex);
        rw_exit(&softmac_hash_lock);
        return (0);

error:
        mutex_enter(&softmac->smac_mutex);
        softmac->smac_attached_left = softmac->smac_attachok_cnt;
        softmac->smac_state = SOFTMAC_ATTACH_DONE;
        cv_broadcast(&softmac->smac_cv);
        mutex_exit(&softmac->smac_mutex);
        return (err);
}

/*
 * This function is called as the result of a newly started dlmgmtd daemon.
 *
 * We walk through every softmac that was created but failed to notify
 * dlmgmtd about it (whose SOFTMAC_NEED_RECREATE flag is set).  This occurs
 * when softmacs are created before dlmgmtd is ready.  For example, during
 * diskless boot, a network device is used (and therefore attached) before
 * the datalink-management service starts dlmgmtd.
 */
/* ARGSUSED */
static uint_t
softmac_mac_recreate(mod_hash_key_t key, mod_hash_val_t *val, void *arg)
{
        softmac_t       *softmac = (softmac_t *)val;
        datalink_id_t   linkid;
        int             err;
        softmac_walk_t  *smwp = arg;

        /*
         * The framework itself must not hold any locks across calls to the
         * mac perimeter. Thus this function does not call any framework
         * function that needs to grab the mac perimeter.
         */
        ASSERT(RW_READ_HELD(&softmac_hash_lock));

        smwp->smw_retry = B_FALSE;
        mutex_enter(&softmac->smac_mutex);
        SOFTMAC_STATE_VERIFY(softmac);
        if (softmac->smac_state == SOFTMAC_ATTACH_INPROG) {
                /*
                 * Wait till softmac_create or softmac_mac_register finishes
                 * Hold the softmac to ensure it stays around. The wait itself
                 * is done in the caller, since we need to drop all locks
                 * including the mod hash's internal lock before calling
                 * cv_wait.
                 */
                smwp->smw_retry = B_TRUE;
                smwp->smw_softmac = softmac;
                softmac->smac_hold_cnt++;
                return (MH_WALK_TERMINATE);
        }

        if ((softmac->smac_state != SOFTMAC_ATTACH_DONE) ||
            !(softmac->smac_flags & SOFTMAC_NEED_RECREATE)) {
                mutex_exit(&softmac->smac_mutex);
                return (MH_WALK_CONTINUE);
        }

        /*
         * Bumping up the smac_hold_cnt allows us to drop the lock. It also
         * makes softmac_destroy() return failure on an attempted device detach.
         * We don't want to hold the lock across calls to other subsystems
         * like kstats, which will happen in the call to dls_devnet_recreate
         */
        softmac->smac_hold_cnt++;
        mutex_exit(&softmac->smac_mutex);

        if (dls_mgmt_create(softmac->smac_devname,
            makedevice(softmac->smac_umajor, softmac->smac_uppa + 1),
            DATALINK_CLASS_PHYS, softmac->smac_media, B_TRUE, &linkid) != 0) {
                softmac_rele_device((dls_dev_handle_t)softmac);
                return (MH_WALK_CONTINUE);
        }

        if ((err = softmac_update_info(softmac, &linkid)) != 0) {
                cmn_err(CE_WARN, "softmac: softmac_update_info() for %s "
                    "failed (%d)", softmac->smac_devname, err);
                softmac_rele_device((dls_dev_handle_t)softmac);
                return (MH_WALK_CONTINUE);
        }

        /*
         * Create a link for this MAC. The link name will be the same
         * as the MAC name.
         */
        if (!(softmac->smac_flags & SOFTMAC_NOSUPP)) {
                err = dls_devnet_recreate(softmac->smac_mh, linkid);
                if (err != 0) {
                        cmn_err(CE_WARN, "softmac: dls_devnet_recreate() for "
                            "%s (linkid %d) failed (%d)",
                            softmac->smac_devname, linkid, err);
                }
        }

        mutex_enter(&softmac->smac_mutex);
        softmac->smac_flags &= ~SOFTMAC_NEED_RECREATE;
        ASSERT(softmac->smac_hold_cnt != 0);
        softmac->smac_hold_cnt--;
        mutex_exit(&softmac->smac_mutex);

        return (MH_WALK_CONTINUE);
}

/*
 * See comments above softmac_mac_recreate().
 */
void
softmac_recreate()
{
        softmac_walk_t  smw;
        softmac_t       *softmac;

        /*
         * Walk through the softmac_hash table. Request to create the
         * [link name, linkid] mapping if we failed to do so.
         */
        do {
                smw.smw_retry = B_FALSE;
                rw_enter(&softmac_hash_lock, RW_READER);
                mod_hash_walk(softmac_hash, softmac_mac_recreate, &smw);
                rw_exit(&softmac_hash_lock);
                if (smw.smw_retry) {
                        /*
                         * softmac_create or softmac_mac_register hasn't yet
                         * finished and the softmac is not yet in the
                         * SOFTMAC_ATTACH_DONE state.
                         */
                        softmac = smw.smw_softmac;
                        cv_wait(&softmac->smac_cv, &softmac->smac_mutex);
                        softmac->smac_hold_cnt--;
                        mutex_exit(&softmac->smac_mutex);
                }
        } while (smw.smw_retry);
}

static int
softmac_m_start(void *arg)
{
        softmac_t       *softmac = arg;
        softmac_lower_t *slp = softmac->smac_lower;
        int             err;

        ASSERT(MAC_PERIM_HELD(softmac->smac_mh));
        /*
         * Bind to SAP 2 on token ring, 0 on other interface types.
         * (SAP 0 has special significance on token ring).
         * Note that the receive-side packets could come anytime after bind.
         */
        err = softmac_send_bind_req(slp, softmac->smac_media == DL_TPR ? 2 : 0);
        if (err != 0)
                return (err);

        /*
         * Put the lower stream to the DL_PROMISC_SAP mode in order to receive
         * all packets of interest.
         *
         * some driver (e.g. the old legacy eri driver) incorrectly passes up
         * packets to DL_PROMISC_SAP stream when the lower stream is not bound,
         * so that we send DL_PROMISON_REQ after DL_BIND_REQ.
         */
        err = softmac_send_promisc_req(slp, DL_PROMISC_SAP, B_TRUE);
        if (err != 0) {
                (void) softmac_send_unbind_req(slp);
                return (err);
        }

        /*
         * Enable capabilities the underlying driver claims to support.
         * Some driver requires this being called after the stream is bound.
         */
        if ((err = softmac_capab_enable(slp)) != 0) {
                (void) softmac_send_promisc_req(slp, DL_PROMISC_SAP, B_FALSE);
                (void) softmac_send_unbind_req(slp);
        }

        return (err);
}

/* ARGSUSED */
static void
softmac_m_stop(void *arg)
{
        softmac_t       *softmac = arg;
        softmac_lower_t *slp = softmac->smac_lower;

        ASSERT(MAC_PERIM_HELD(softmac->smac_mh));

        /*
         * It is not needed to reset zerocopy, MDT or HCKSUM capabilities.
         */
        (void) softmac_send_promisc_req(slp, DL_PROMISC_SAP, B_FALSE);
        (void) softmac_send_unbind_req(slp);
}

/*
 * Set up the lower stream above the legacy device. There are two different
 * type of lower streams:
 *
 * - Shared lower-stream
 *
 * Shared by all GLDv3 MAC clients. Put the lower stream to the DLIOCRAW
 * mode to send and receive the raw data. Further, put the lower stream into
 * DL_PROMISC_SAP mode to receive all packets of interest.
 *
 * - Dedicated lower-stream
 *
 * The lower-stream which is dedicated to upper IP/ARP stream. This is used
 * as fast-path for IP. In this case, the second argument is the pointer to
 * the softmac upper-stream.
 */
int
softmac_lower_setup(softmac_t *softmac, softmac_upper_t *sup,
    softmac_lower_t **slpp)
{
        ldi_ident_t             li;
        dev_t                   dev;
        ldi_handle_t            lh = NULL;
        softmac_lower_t         *slp = NULL;
        smac_ioc_start_t        start_arg;
        struct strioctl         strioc;
        uint32_t                notifications;
        int                     err, rval;

        if ((err = ldi_ident_from_dip(softmac_dip, &li)) != 0)
                return (err);

        /*
         * The GLDv3 framework makes sure that mac_unregister(), mac_open(),
         * and mac_close() cannot be called at the same time. So we don't
         * need any protection to access softmac here.
         */
        dev = softmac->smac_dev;

        err = ldi_open_by_dev(&dev, OTYP_CHR, FREAD|FWRITE, kcred, &lh, li);
        ldi_ident_release(li);
        if (err != 0)
                goto done;

        /*
         * Pop all the intermediate modules. The autopushed modules will
         * be pushed when the softmac node is opened.
         */
        while (ldi_ioctl(lh, I_POP, 0, FKIOCTL, kcred, &rval) == 0)
                ;

        if ((softmac->smac_style == DL_STYLE2) &&
            ((err = dl_attach(lh, softmac->smac_uppa, NULL)) != 0)) {
                goto done;
        }

        /*
         * If this is the shared-lower-stream, put the lower stream to
         * the DLIOCRAW mode to send/receive raw data.
         */
        if ((sup == NULL) && (err = ldi_ioctl(lh, DLIOCRAW, 0, FKIOCTL,
            kcred, &rval)) != 0) {
                goto done;
        }

        /*
         * Then push the softmac shim layer atop the lower stream.
         */
        if ((err = ldi_ioctl(lh, I_PUSH, (intptr_t)SOFTMAC_DEV_NAME, FKIOCTL,
            kcred, &rval)) != 0) {
                goto done;
        }

        /*
         * Send the ioctl to get the slp pointer.
         */
        strioc.ic_cmd = SMAC_IOC_START;
        strioc.ic_timout = INFTIM;
        strioc.ic_len = sizeof (start_arg);
        strioc.ic_dp = (char *)&start_arg;

        if ((err = ldi_ioctl(lh, I_STR, (intptr_t)&strioc, FKIOCTL,
            kcred, &rval)) != 0) {
                goto done;
        }
        slp = start_arg.si_slp;
        slp->sl_sup = sup;
        slp->sl_lh = lh;
        slp->sl_softmac = softmac;
        *slpp = slp;

        if (sup != NULL) {
                slp->sl_rxinfo = &sup->su_rxinfo;
        } else {
                /*
                 * Send DL_NOTIFY_REQ to enable certain DL_NOTIFY_IND.
                 * We don't have to wait for the ack.
                 */
                notifications = DL_NOTE_PHYS_ADDR | DL_NOTE_LINK_UP |
                    DL_NOTE_LINK_DOWN | DL_NOTE_PROMISC_ON_PHYS |
                    DL_NOTE_PROMISC_OFF_PHYS;

                (void) softmac_send_notify_req(slp,
                    (notifications & softmac->smac_notifications));
        }

done:
        if (err != 0)
                (void) ldi_close(lh, FREAD|FWRITE, kcred);
        return (err);
}

static int
softmac_m_open(void *arg)
{
        softmac_t       *softmac = arg;
        softmac_lower_t *slp;
        int             err;

        ASSERT(MAC_PERIM_HELD(softmac->smac_mh));

        if ((err = softmac_lower_setup(softmac, NULL, &slp)) != 0)
                return (err);

        softmac->smac_lower = slp;
        return (0);
}

static void
softmac_m_close(void *arg)
{
        softmac_t       *softmac = arg;
        softmac_lower_t *slp;

        ASSERT(MAC_PERIM_HELD(softmac->smac_mh));
        slp = softmac->smac_lower;
        ASSERT(slp != NULL);

        /*
         * Note that slp is destroyed when lh is closed.
         */
        (void) ldi_close(slp->sl_lh, FREAD|FWRITE, kcred);
        softmac->smac_lower = NULL;
}

/*
 * Softmac supports two priviate link properteis:
 *
 * - "_fastpath"
 *
 *    This is a read-only link property which points out the current data-path
 *    model of the given legacy link. The possible values are "disabled" and
 *    "enabled".
 *
 * - "_disable_fastpath"
 *
 *    This is a read-write link property which can be used to disable or enable
 *    the fast-path of the given legacy link. The possible values are "true"
 *    and "false". Note that even when "_disable_fastpath" is set to be
 *    "false", the fast-path may still not be enabled since there may be
 *    other mac cleints that request the fast-path to be disabled.
 */
/* ARGSUSED */
static int
softmac_m_setprop(void *arg, const char *name, mac_prop_id_t id,
    uint_t valsize, const void *val)
{
        softmac_t       *softmac = arg;

        if (id != MAC_PROP_PRIVATE || strcmp(name, "_disable_fastpath") != 0)
                return (ENOTSUP);

        if (strcmp(val, "true") == 0)
                return (softmac_datapath_switch(softmac, B_TRUE, B_TRUE));
        else if (strcmp(val, "false") == 0)
                return (softmac_datapath_switch(softmac, B_FALSE, B_TRUE));
        else
                return (EINVAL);
}

static int
softmac_m_getprop(void *arg, const char *name, mac_prop_id_t id,
    uint_t valsize, void *val)
{
        softmac_t       *softmac = arg;
        char            *fpstr;

        if (id != MAC_PROP_PRIVATE)
                return (ENOTSUP);

        if (strcmp(name, "_fastpath") == 0) {
                mutex_enter(&softmac->smac_fp_mutex);
                fpstr = (DATAPATH_MODE(softmac) == SOFTMAC_SLOWPATH) ?
                    "disabled" : "enabled";
                mutex_exit(&softmac->smac_fp_mutex);
        } else if (strcmp(name, "_disable_fastpath") == 0) {
                fpstr = softmac->smac_fastpath_admin_disabled ?
                    "true" : "false";
        } else if (strcmp(name, "_softmac") == 0) {
                fpstr = "true";
        } else {
                return (ENOTSUP);
        }

        return (strlcpy(val, fpstr, valsize) >= valsize ? EINVAL : 0);
}

static void
softmac_m_propinfo(void *arg, const char *name, mac_prop_id_t id,
    mac_prop_info_handle_t prh)
{
        _NOTE(ARGUNUSED(arg));

        if (id != MAC_PROP_PRIVATE)
                return;

        if (strcmp(name, "_fastpath") == 0) {
                mac_prop_info_set_perm(prh, MAC_PROP_PERM_READ);
        } else if (strcmp(name, "_disable_fastpath") == 0) {
                mac_prop_info_set_default_str(prh, "false");
        }

}

int
softmac_hold_device(dev_t dev, dls_dev_handle_t *ddhp)
{
        dev_info_t      *dip;
        char            devname[MAXNAMELEN];
        softmac_t       *softmac;
        major_t         major;
        int             ppa, err = 0, inst;

        major = getmajor(dev);
        ppa = getminor(dev) - 1;

        /*
         * For GLDv3 devices, look up the device instance using getinfo(9e).
         * Otherwise, fall back to the old assumption that inst == ppa.  The
         * GLDV3_DRV() macro depends on the driver module being loaded, hence
         * the call to ddi_hold_driver().
         */
        if (ddi_hold_driver(major) == NULL)
                return (ENXIO);
        if (GLDV3_DRV(major)) {
                if ((inst = dev_to_instance(dev)) < 0)
                        err = ENOENT;
        } else {
                inst = ppa;
        }
        ddi_rele_driver(major);
        if (err != 0)
                return (err);

        /*
         * First try to hold this device instance to force device to attach
         * and ensure that the softmac entry gets created in net_postattach().
         */
        if ((dip = ddi_hold_devi_by_instance(major, inst, 0)) == NULL)
                return (ENOENT);

        /*
         * Exclude non-physical network device instances, for example, aggr0.
         * Note: this check *must* occur after the dip is held, or else
         * NETWORK_PHYSDRV might return false incorrectly.  The
         * DN_NETWORK_PHYSDRIVER flag used by NETWORK_PHYSDRV() gets set if
         * ddi_create_minor_node() is called during the device's attach
         * phase.
         */
        if (!NETWORK_PHYSDRV(major)) {
                ddi_release_devi(dip);
                return (ENOENT);
        }

        /* Now wait for its softmac to be created. */
        (void) snprintf(devname, MAXNAMELEN, "%s%d", ddi_major_to_name(major),
            ppa);
again:
        rw_enter(&softmac_hash_lock, RW_READER);

        if (mod_hash_find(softmac_hash, (mod_hash_key_t)devname,
            (mod_hash_val_t *)&softmac) != 0) {
                /*
                 * This is rare but possible. It could happen when pre-detach
                 * routine of the device succeeds. But the softmac will then
                 * be recreated when device fails to detach (as this device
                 * is held).
                 */
                mutex_enter(&smac_global_lock);
                rw_exit(&softmac_hash_lock);
                cv_wait(&smac_global_cv, &smac_global_lock);
                mutex_exit(&smac_global_lock);
                goto again;
        }

        /*
         * Bump smac_hold_cnt to prevent device detach.
         */
        mutex_enter(&softmac->smac_mutex);
        softmac->smac_hold_cnt++;
        rw_exit(&softmac_hash_lock);

        /*
         * Wait till the device is fully attached.
         */
        while (softmac->smac_state != SOFTMAC_ATTACH_DONE)
                cv_wait(&softmac->smac_cv, &softmac->smac_mutex);

        SOFTMAC_STATE_VERIFY(softmac);

        if ((err = softmac->smac_attacherr) != 0)
                softmac->smac_hold_cnt--;
        else
                *ddhp = (dls_dev_handle_t)softmac;
        mutex_exit(&softmac->smac_mutex);

        ddi_release_devi(dip);
        return (err);
}

void
softmac_rele_device(dls_dev_handle_t ddh)
{
        if (ddh != NULL)
                softmac_rele((softmac_t *)ddh);
}

int
softmac_hold(dev_t dev, softmac_t **softmacp)
{
        softmac_t       *softmac;
        char            *drv;
        mac_handle_t    mh;
        char            mac[MAXNAMELEN];
        int             err;

        if ((drv = ddi_major_to_name(getmajor(dev))) == NULL)
                return (EINVAL);

        (void) snprintf(mac, MAXNAMELEN, "%s%d", drv, getminor(dev) - 1);
        if ((err = mac_open(mac, &mh)) != 0)
                return (err);

        softmac = (softmac_t *)mac_driver(mh);

        mutex_enter(&softmac->smac_mutex);
        softmac->smac_hold_cnt++;
        mutex_exit(&softmac->smac_mutex);
        mac_close(mh);
        *softmacp = softmac;
        return (0);
}

void
softmac_rele(softmac_t *softmac)
{
        mutex_enter(&softmac->smac_mutex);
        softmac->smac_hold_cnt--;
        mutex_exit(&softmac->smac_mutex);
}