xref: /onnv-gate/usr/src/uts/common/io/vnic/vnic_dev.c (revision 9514:7732f19e67a6)

/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/conf.h>
#include <sys/cmn_err.h>
#include <sys/list.h>
#include <sys/ksynch.h>
#include <sys/kmem.h>
#include <sys/stream.h>
#include <sys/modctl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/atomic.h>
#include <sys/stat.h>
#include <sys/modhash.h>
#include <sys/strsubr.h>
#include <sys/strsun.h>
#include <sys/dlpi.h>
#include <sys/mac.h>
#include <sys/mac_provider.h>
#include <sys/mac_client.h>
#include <sys/mac_client_priv.h>
#include <sys/mac_ether.h>
#include <sys/dls.h>
#include <sys/pattr.h>
#include <sys/time.h>
#include <sys/vlan.h>
#include <sys/vnic.h>
#include <sys/vnic_impl.h>
#include <sys/mac_flow_impl.h>
#include <inet/ip_impl.h>

/*
 * Note that for best performance, the VNIC is a passthrough design.
 * For each VNIC corresponds a MAC client of the underlying MAC (lower MAC).
 * This MAC client is opened by the VNIC driver at VNIC creation,
 * and closed when the VNIC is deleted.
 * When a MAC client of the VNIC itself opens a VNIC, the MAC layer
 * (upper MAC) detects that the MAC being opened is a VNIC. Instead
 * of allocating a new MAC client, it asks the VNIC driver to return
 * the lower MAC client handle associated with the VNIC, and that handle
 * is returned to the upper MAC client directly. This allows access
 * by upper MAC clients of the VNIC to have direct access to the lower
 * MAC client for the control path and data path.
 *
 * Due to this passthrough, some of the entry points exported by the
 * VNIC driver are never directly invoked. These entry points include
 * vnic_m_start, vnic_m_stop, vnic_m_promisc, vnic_m_multicst, etc.
 */

static int vnic_m_start(void *);
static void vnic_m_stop(void *);
static int vnic_m_promisc(void *, boolean_t);
static int vnic_m_multicst(void *, boolean_t, const uint8_t *);
static int vnic_m_unicst(void *, const uint8_t *);
static int vnic_m_stat(void *, uint_t, uint64_t *);
static void vnic_m_ioctl(void *, queue_t *, mblk_t *);
static int vnic_m_setprop(void *, const char *, mac_prop_id_t, uint_t,
    const void *);
static int vnic_m_getprop(void *, const char *, mac_prop_id_t, uint_t,
    uint_t, void *, uint_t *);
static mblk_t *vnic_m_tx(void *, mblk_t *);
static boolean_t vnic_m_capab_get(void *, mac_capab_t, void *);
static void vnic_notify_cb(void *, mac_notify_type_t);

static kmem_cache_t	*vnic_cache;
static krwlock_t	vnic_lock;
static uint_t		vnic_count;

#define	ANCHOR_VNIC_MIN_MTU	576
#define	ANCHOR_VNIC_MAX_MTU	9000

/* hash of VNICs (vnic_t's), keyed by VNIC id */
static mod_hash_t	*vnic_hash;
#define	VNIC_HASHSZ	64
#define	VNIC_HASH_KEY(vnic_id)	((mod_hash_key_t)(uintptr_t)vnic_id)

#define	VNIC_M_CALLBACK_FLAGS	\
	(MC_IOCTL | MC_GETCAPAB | MC_SETPROP | MC_GETPROP)

static mac_callbacks_t vnic_m_callbacks = {
	VNIC_M_CALLBACK_FLAGS,
	vnic_m_stat,
	vnic_m_start,
	vnic_m_stop,
	vnic_m_promisc,
	vnic_m_multicst,
	vnic_m_unicst,
	vnic_m_tx,
	vnic_m_ioctl,
	vnic_m_capab_get,
	NULL,
	NULL,
	vnic_m_setprop,
	vnic_m_getprop
};

void
vnic_dev_init(void)
{
	vnic_cache = kmem_cache_create("vnic_cache",
	    sizeof (vnic_t), 0, NULL, NULL, NULL, NULL, NULL, 0);

	vnic_hash = mod_hash_create_idhash("vnic_hash",
	    VNIC_HASHSZ, mod_hash_null_valdtor);

	rw_init(&vnic_lock, NULL, RW_DEFAULT, NULL);

	vnic_count = 0;
}

void
vnic_dev_fini(void)
{
	ASSERT(vnic_count == 0);

	rw_destroy(&vnic_lock);
	mod_hash_destroy_idhash(vnic_hash);
	kmem_cache_destroy(vnic_cache);
}

uint_t
vnic_dev_count(void)
{
	return (vnic_count);
}

static vnic_ioc_diag_t
vnic_mac2vnic_diag(mac_diag_t diag)
{
	switch (diag) {
	case MAC_DIAG_MACADDR_NIC:
		return (VNIC_IOC_DIAG_MACADDR_NIC);
	case MAC_DIAG_MACADDR_INUSE:
		return (VNIC_IOC_DIAG_MACADDR_INUSE);
	case MAC_DIAG_MACADDR_INVALID:
		return (VNIC_IOC_DIAG_MACADDR_INVALID);
	case MAC_DIAG_MACADDRLEN_INVALID:
		return (VNIC_IOC_DIAG_MACADDRLEN_INVALID);
	case MAC_DIAG_MACFACTORYSLOTINVALID:
		return (VNIC_IOC_DIAG_MACFACTORYSLOTINVALID);
	case MAC_DIAG_MACFACTORYSLOTUSED:
		return (VNIC_IOC_DIAG_MACFACTORYSLOTUSED);
	case MAC_DIAG_MACFACTORYSLOTALLUSED:
		return (VNIC_IOC_DIAG_MACFACTORYSLOTALLUSED);
	case MAC_DIAG_MACFACTORYNOTSUP:
		return (VNIC_IOC_DIAG_MACFACTORYNOTSUP);
	case MAC_DIAG_MACPREFIX_INVALID:
		return (VNIC_IOC_DIAG_MACPREFIX_INVALID);
	case MAC_DIAG_MACPREFIXLEN_INVALID:
		return (VNIC_IOC_DIAG_MACPREFIXLEN_INVALID);
	case MAC_DIAG_MACNO_HWRINGS:
		return (VNIC_IOC_DIAG_NO_HWRINGS);
	default:
		return (VNIC_IOC_DIAG_NONE);
	}
}

static int
vnic_unicast_add(vnic_t *vnic, vnic_mac_addr_type_t vnic_addr_type,
    int *addr_slot, uint_t prefix_len, int *addr_len_ptr_arg,
    uint8_t *mac_addr_arg, uint16_t flags, vnic_ioc_diag_t *diag,
    uint16_t vid)
{
	mac_diag_t mac_diag;
	uint16_t mac_flags = 0;
	int err;
	uint_t addr_len;

	if (flags & VNIC_IOC_CREATE_NODUPCHECK)
		mac_flags |= MAC_UNICAST_NODUPCHECK;

	switch (vnic_addr_type) {
	case VNIC_MAC_ADDR_TYPE_FIXED:
		/*
		 * The MAC address value to assign to the VNIC
		 * is already provided in mac_addr_arg. addr_len_ptr_arg
		 * already contains the MAC address length.
		 */
		break;

	case VNIC_MAC_ADDR_TYPE_RANDOM:
		/*
		 * Random MAC address. There are two sub-cases:
		 *
		 * 1 - If mac_len == 0, a new MAC address is generated.
		 *	The length of the MAC address to generated depends
		 *	on the type of MAC used. The prefix to use for the MAC
		 *	address is stored in the most significant bytes
		 *	of the mac_addr argument, and its length is specified
		 *	by the mac_prefix_len argument. This prefix can
		 *	correspond to a IEEE OUI in the case of Ethernet,
		 *	for example.
		 *
		 * 2 - If mac_len > 0, the address was already picked
		 *	randomly, and is now passed back during VNIC
		 *	re-creation. The mac_addr argument contains the MAC
		 *	address that was generated. We distinguish this
		 *	case from the fixed MAC address case, since we
		 *	want the user consumers to know, when they query
		 *	the list of VNICs, that a VNIC was assigned a
		 *	random MAC address vs assigned a fixed address
		 *	specified by the user.
		 */

		/*
		 * If it's a pre-generated address, we're done. mac_addr_arg
		 * and addr_len_ptr_arg already contain the MAC address
		 * value and length.
		 */
		if (*addr_len_ptr_arg > 0)
			break;

		/* generate a new random MAC address */
		if ((err = mac_addr_random(vnic->vn_mch,
		    prefix_len, mac_addr_arg, &mac_diag)) != 0) {
			*diag = vnic_mac2vnic_diag(mac_diag);
			return (err);
		}
		*addr_len_ptr_arg = mac_addr_len(vnic->vn_lower_mh);
		break;

	case VNIC_MAC_ADDR_TYPE_FACTORY:
		err = mac_addr_factory_reserve(vnic->vn_mch, addr_slot);
		if (err != 0) {
			if (err == EINVAL)
				*diag = VNIC_IOC_DIAG_MACFACTORYSLOTINVALID;
			if (err == EBUSY)
				*diag = VNIC_IOC_DIAG_MACFACTORYSLOTUSED;
			if (err == ENOSPC)
				*diag = VNIC_IOC_DIAG_MACFACTORYSLOTALLUSED;
			return (err);
		}

		mac_addr_factory_value(vnic->vn_lower_mh, *addr_slot,
		    mac_addr_arg, &addr_len, NULL, NULL);
		*addr_len_ptr_arg = addr_len;
		break;

	case VNIC_MAC_ADDR_TYPE_AUTO:
		/* first try to allocate a factory MAC address */
		err = mac_addr_factory_reserve(vnic->vn_mch, addr_slot);
		if (err == 0) {
			mac_addr_factory_value(vnic->vn_lower_mh, *addr_slot,
			    mac_addr_arg, &addr_len, NULL, NULL);
			vnic_addr_type = VNIC_MAC_ADDR_TYPE_FACTORY;
			*addr_len_ptr_arg = addr_len;
			break;
		}

		/*
		 * Allocating a factory MAC address failed, generate a
		 * random MAC address instead.
		 */
		if ((err = mac_addr_random(vnic->vn_mch,
		    prefix_len, mac_addr_arg, &mac_diag)) != 0) {
			*diag = vnic_mac2vnic_diag(mac_diag);
			return (err);
		}
		*addr_len_ptr_arg = mac_addr_len(vnic->vn_lower_mh);
		vnic_addr_type = VNIC_MAC_ADDR_TYPE_RANDOM;
		break;
	case VNIC_MAC_ADDR_TYPE_PRIMARY:
		/*
		 * We get the address here since we copy it in the
		 * vnic's vn_addr.
		 */
		mac_unicast_primary_get(vnic->vn_lower_mh, mac_addr_arg);
		*addr_len_ptr_arg = mac_addr_len(vnic->vn_lower_mh);
		mac_flags |= MAC_UNICAST_VNIC_PRIMARY;
		break;
	}

	vnic->vn_addr_type = vnic_addr_type;

	err = mac_unicast_add(vnic->vn_mch, mac_addr_arg, mac_flags,
	    &vnic->vn_muh, vid, &mac_diag);
	if (err != 0) {
		if (vnic_addr_type == VNIC_MAC_ADDR_TYPE_FACTORY) {
			/* release factory MAC address */
			mac_addr_factory_release(vnic->vn_mch, *addr_slot);
		}
		*diag = vnic_mac2vnic_diag(mac_diag);
	}

	return (err);
}

/*
 * Create a new VNIC upon request from administrator.
 * Returns 0 on success, an errno on failure.
 */
/* ARGSUSED */
int
vnic_dev_create(datalink_id_t vnic_id, datalink_id_t linkid,
    vnic_mac_addr_type_t *vnic_addr_type, int *mac_len, uchar_t *mac_addr,
    int *mac_slot, uint_t mac_prefix_len, uint16_t vid,
    mac_resource_props_t *mrp, uint32_t flags, vnic_ioc_diag_t *diag)
{
	vnic_t *vnic;
	mac_register_t *mac;
	int err;
	boolean_t is_anchor = ((flags & VNIC_IOC_CREATE_ANCHOR) != 0);
	char vnic_name[MAXNAMELEN];
	const mac_info_t *minfop;
	uint32_t req_hwgrp_flag = ((flags & VNIC_IOC_CREATE_REQ_HWRINGS) != 0) ?
	    MAC_OPEN_FLAGS_REQ_HWRINGS : 0;

	*diag = VNIC_IOC_DIAG_NONE;

	rw_enter(&vnic_lock, RW_WRITER);

	/* does a VNIC with the same id already exist? */
	err = mod_hash_find(vnic_hash, VNIC_HASH_KEY(vnic_id),
	    (mod_hash_val_t *)&vnic);
	if (err == 0) {
		rw_exit(&vnic_lock);
		return (EEXIST);
	}

	vnic = kmem_cache_alloc(vnic_cache, KM_NOSLEEP);
	if (vnic == NULL) {
		rw_exit(&vnic_lock);
		return (ENOMEM);
	}

	bzero(vnic, sizeof (*vnic));

	vnic->vn_id = vnic_id;
	vnic->vn_link_id = linkid;

	if (!is_anchor) {
		if (linkid == DATALINK_INVALID_LINKID) {
			err = EINVAL;
			goto bail;
		}

		/*
		 * Open the lower MAC and assign its initial bandwidth and
		 * MAC address. We do this here during VNIC creation and
		 * do not wait until the upper MAC client open so that we
		 * can validate the VNIC creation parameters (bandwidth,
		 * MAC address, etc) and reserve a factory MAC address if
		 * one was requested.
		 */
		err = mac_open_by_linkid(linkid, &vnic->vn_lower_mh);
		if (err != 0)
			goto bail;

		/*
		 * VNIC(vlan) over VNICs(vlans) is not supported.
		 */
		if (mac_is_vnic(vnic->vn_lower_mh)) {
			err = EINVAL;
			goto bail;
		}

		/* only ethernet support for now */
		minfop = mac_info(vnic->vn_lower_mh);
		if (minfop->mi_nativemedia != DL_ETHER) {
			err = ENOTSUP;
			goto bail;
		}

		(void) dls_mgmt_get_linkinfo(vnic_id, vnic_name, NULL, NULL,
		    NULL);
		err = mac_client_open(vnic->vn_lower_mh, &vnic->vn_mch,
		    vnic_name, MAC_OPEN_FLAGS_IS_VNIC | req_hwgrp_flag);
		if (err != 0)
			goto bail;

		if (mrp != NULL) {
			err = mac_client_set_resources(vnic->vn_mch, mrp);
			if (err != 0)
				goto bail;
		}
		/* assign a MAC address to the VNIC */

		err = vnic_unicast_add(vnic, *vnic_addr_type, mac_slot,
		    mac_prefix_len, mac_len, mac_addr, flags, diag, vid);
		if (err != 0) {
			vnic->vn_muh = NULL;
			if (diag != NULL && req_hwgrp_flag != 0)
				*diag = VNIC_IOC_DIAG_NO_HWRINGS;
			goto bail;
		}

		/* register to receive notification from underlying MAC */
		vnic->vn_mnh = mac_notify_add(vnic->vn_lower_mh, vnic_notify_cb,
		    vnic);

		*vnic_addr_type = vnic->vn_addr_type;
		vnic->vn_addr_len = *mac_len;
		vnic->vn_vid = vid;

		bcopy(mac_addr, vnic->vn_addr, vnic->vn_addr_len);

		if (vnic->vn_addr_type == VNIC_MAC_ADDR_TYPE_FACTORY)
			vnic->vn_slot_id = *mac_slot;

		/* set the initial VNIC capabilities */
		if (!mac_capab_get(vnic->vn_lower_mh, MAC_CAPAB_HCKSUM,
		    &vnic->vn_hcksum_txflags))
			vnic->vn_hcksum_txflags = 0;
	}

	/* register with the MAC module */
	if ((mac = mac_alloc(MAC_VERSION)) == NULL)
		goto bail;

	mac->m_type_ident = MAC_PLUGIN_IDENT_ETHER;
	mac->m_driver = vnic;
	mac->m_dip = vnic_get_dip();
	mac->m_instance = (uint_t)-1;
	mac->m_src_addr = vnic->vn_addr;
	mac->m_callbacks = &vnic_m_callbacks;

	if (!is_anchor) {
		/*
		 * If this is a VNIC based VLAN, then we check for the
		 * margin unless it has been created with the force
		 * flag. If we are configuring a VLAN over an etherstub,
		 * we don't check the margin even if force is not set.
		 */
		if (vid == 0 || (flags & VNIC_IOC_CREATE_FORCE) != 0) {
			if (vid != VLAN_ID_NONE)
				vnic->vn_force = B_TRUE;
			/*
			 * As the current margin size of the underlying mac is
			 * used to determine the margin size of the VNIC
			 * itself, request the underlying mac not to change
			 * to a smaller margin size.
			 */
			err = mac_margin_add(vnic->vn_lower_mh,
			    &vnic->vn_margin, B_TRUE);
			ASSERT(err == 0);
		} else {
			vnic->vn_margin = VLAN_TAGSZ;
			err = mac_margin_add(vnic->vn_lower_mh,
			    &vnic->vn_margin, B_FALSE);
			if (err != 0) {
				mac_free(mac);
				if (diag != NULL)
					*diag = VNIC_IOC_DIAG_MACMARGIN_INVALID;
				goto bail;
			}
		}

		mac_sdu_get(vnic->vn_lower_mh, &mac->m_min_sdu,
		    &mac->m_max_sdu);
	} else {
		vnic->vn_margin = VLAN_TAGSZ;
		mac->m_min_sdu = ANCHOR_VNIC_MIN_MTU;
		mac->m_max_sdu = ANCHOR_VNIC_MAX_MTU;
	}

	mac->m_margin = vnic->vn_margin;

	err = mac_register(mac, &vnic->vn_mh);
	mac_free(mac);
	if (err != 0) {
		VERIFY(is_anchor || mac_margin_remove(vnic->vn_lower_mh,
		    vnic->vn_margin) == 0);
		goto bail;
	}

	/* Set the VNIC's MAC in the client */
	if (!is_anchor)
		mac_set_upper_mac(vnic->vn_mch, vnic->vn_mh);

	if ((err = dls_devnet_create(vnic->vn_mh, vnic->vn_id)) != 0) {
		VERIFY(is_anchor || mac_margin_remove(vnic->vn_lower_mh,
		    vnic->vn_margin) == 0);
		(void) mac_unregister(vnic->vn_mh);
		goto bail;
	}

	/* add new VNIC to hash table */
	err = mod_hash_insert(vnic_hash, VNIC_HASH_KEY(vnic_id),
	    (mod_hash_val_t)vnic);
	ASSERT(err == 0);
	vnic_count++;

	vnic->vn_enabled = B_TRUE;
	rw_exit(&vnic_lock);

	return (0);

bail:
	rw_exit(&vnic_lock);
	if (!is_anchor) {
		if (vnic->vn_mnh != NULL)
			(void) mac_notify_remove(vnic->vn_mnh, B_TRUE);
		if (vnic->vn_muh != NULL)
			(void) mac_unicast_remove(vnic->vn_mch, vnic->vn_muh);
		if (vnic->vn_mch != NULL)
			mac_client_close(vnic->vn_mch, MAC_CLOSE_FLAGS_IS_VNIC);
		if (vnic->vn_lower_mh != NULL)
			mac_close(vnic->vn_lower_mh);
	}

	kmem_cache_free(vnic_cache, vnic);
	return (err);
}

/*
 * Modify the properties of an existing VNIC.
 */
/* ARGSUSED */
int
vnic_dev_modify(datalink_id_t vnic_id, uint_t modify_mask,
    vnic_mac_addr_type_t mac_addr_type, uint_t mac_len, uchar_t *mac_addr,
    uint_t mac_slot, mac_resource_props_t *mrp)
{
	vnic_t *vnic = NULL;

	rw_enter(&vnic_lock, RW_WRITER);

	if (mod_hash_find(vnic_hash, VNIC_HASH_KEY(vnic_id),
	    (mod_hash_val_t *)&vnic) != 0) {
		rw_exit(&vnic_lock);
		return (ENOENT);
	}

	rw_exit(&vnic_lock);

	return (0);
}

/* ARGSUSED */
int
vnic_dev_delete(datalink_id_t vnic_id, uint32_t flags)
{
	vnic_t *vnic = NULL;
	mod_hash_val_t val;
	datalink_id_t tmpid;
	int rc;

	rw_enter(&vnic_lock, RW_WRITER);

	if (mod_hash_find(vnic_hash, VNIC_HASH_KEY(vnic_id),
	    (mod_hash_val_t *)&vnic) != 0) {
		rw_exit(&vnic_lock);
		return (ENOENT);
	}

	if ((rc = dls_devnet_destroy(vnic->vn_mh, &tmpid, B_TRUE)) != 0) {
		rw_exit(&vnic_lock);
		return (rc);
	}

	ASSERT(vnic_id == tmpid);

	/*
	 * We cannot unregister the MAC yet. Unregistering would
	 * free up mac_impl_t which should not happen at this time.
	 * So disable mac_impl_t by calling mac_disable(). This will prevent
	 * any new claims on mac_impl_t.
	 */
	if ((rc = mac_disable(vnic->vn_mh)) != 0) {
		(void) dls_devnet_create(vnic->vn_mh, vnic_id);
		rw_exit(&vnic_lock);
		return (rc);
	}

	vnic->vn_enabled = B_FALSE;
	(void) mod_hash_remove(vnic_hash, VNIC_HASH_KEY(vnic_id), &val);
	ASSERT(vnic == (vnic_t *)val);
	vnic_count--;
	rw_exit(&vnic_lock);

	/*
	 * XXX-nicolas shouldn't have a void cast here, if it's
	 * expected that the function will never fail, then we should
	 * have an ASSERT().
	 */
	(void) mac_unregister(vnic->vn_mh);

	if (vnic->vn_lower_mh != NULL) {
		/*
		 * Check if MAC address for the vnic was obtained from the
		 * factory MAC addresses. If yes, release it.
		 */
		if (vnic->vn_addr_type == VNIC_MAC_ADDR_TYPE_FACTORY) {
			(void) mac_addr_factory_release(vnic->vn_mch,
			    vnic->vn_slot_id);
		}
		(void) mac_margin_remove(vnic->vn_lower_mh, vnic->vn_margin);
		(void) mac_notify_remove(vnic->vn_mnh, B_TRUE);
		(void) mac_unicast_remove(vnic->vn_mch, vnic->vn_muh);
		mac_client_close(vnic->vn_mch, MAC_CLOSE_FLAGS_IS_VNIC);
		mac_close(vnic->vn_lower_mh);
	}

	kmem_cache_free(vnic_cache, vnic);
	return (0);
}

/* ARGSUSED */
mblk_t *
vnic_m_tx(void *arg, mblk_t *mp_chain)
{
	/*
	 * This function could be invoked for an anchor VNIC when sending
	 * broadcast and multicast packets, and unicast packets which did
	 * not match any local known destination.
	 */
	freemsgchain(mp_chain);
	return (NULL);
}

/*ARGSUSED*/
static void
vnic_m_ioctl(void *arg, queue_t *q, mblk_t *mp)
{
	miocnak(q, mp, 0, ENOTSUP);
}

/*
 * This entry point cannot be passed-through, since it is invoked
 * for the per-VNIC kstats which must be exported independently
 * of the existence of VNIC MAC clients.
 */
static int
vnic_m_stat(void *arg, uint_t stat, uint64_t *val)
{
	vnic_t *vnic = arg;
	int rval = 0;

	if (vnic->vn_lower_mh == NULL) {
		/*
		 * It's an anchor VNIC, which does not have any
		 * statistics in itself.
		 */
		return (ENOTSUP);
	}

	/*
	 * ENOTSUP must be reported for unsupported stats, the VNIC
	 * driver reports a subset of the stats that would
	 * be returned by a real piece of hardware.
	 */

	switch (stat) {
	case MAC_STAT_LINK_STATE:
	case MAC_STAT_LINK_UP:
	case MAC_STAT_PROMISC:
	case MAC_STAT_IFSPEED:
	case MAC_STAT_MULTIRCV:
	case MAC_STAT_MULTIXMT:
	case MAC_STAT_BRDCSTRCV:
	case MAC_STAT_BRDCSTXMT:
	case MAC_STAT_OPACKETS:
	case MAC_STAT_OBYTES:
	case MAC_STAT_IERRORS:
	case MAC_STAT_OERRORS:
	case MAC_STAT_RBYTES:
	case MAC_STAT_IPACKETS:
		*val = mac_client_stat_get(vnic->vn_mch, stat);
		break;
	default:
		rval = ENOTSUP;
	}

	return (rval);
}

/*
 * Invoked by the upper MAC to retrieve the lower MAC client handle
 * corresponding to a VNIC. A pointer to this function is obtained
 * by the upper MAC via capability query.
 *
 * XXX-nicolas Note: this currently causes all VNIC MAC clients to
 * receive the same MAC client handle for the same VNIC. This is ok
 * as long as we have only one VNIC MAC client which sends and
 * receives data, but we don't currently enforce this at the MAC layer.
 */
static void *
vnic_mac_client_handle(void *vnic_arg)
{
	vnic_t *vnic = vnic_arg;

	return (vnic->vn_mch);
}


/*
 * Return information about the specified capability.
 */
/* ARGSUSED */
static boolean_t
vnic_m_capab_get(void *arg, mac_capab_t cap, void *cap_data)
{
	vnic_t *vnic = arg;

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

		*hcksum_txflags = vnic->vn_hcksum_txflags &
		    (HCKSUM_INET_FULL_V4 | HCKSUM_IPHDRCKSUM |
		    HCKSUM_INET_PARTIAL);
		break;
	}
	case MAC_CAPAB_VNIC: {
		mac_capab_vnic_t *vnic_capab = cap_data;

		if (vnic->vn_lower_mh == NULL) {
			/*
			 * It's an anchor VNIC, we don't have an underlying
			 * NIC and MAC client handle.
			 */
			return (B_FALSE);
		}

		if (vnic_capab != NULL) {
			vnic_capab->mcv_arg = vnic;
			vnic_capab->mcv_mac_client_handle =
			    vnic_mac_client_handle;
		}
		break;
	}
	case MAC_CAPAB_ANCHOR_VNIC: {
		/* since it's an anchor VNIC we don't have lower mac handle */
		if (vnic->vn_lower_mh == NULL) {
			ASSERT(vnic->vn_link_id == 0);
			return (B_TRUE);
		}
		return (B_FALSE);
	}
	case MAC_CAPAB_NO_NATIVEVLAN:
	case MAC_CAPAB_NO_ZCOPY:
		return (B_TRUE);
	default:
		return (B_FALSE);
	}
	return (B_TRUE);
}

/* ARGSUSED */
static int
vnic_m_start(void *arg)
{
	return (0);
}

/* ARGSUSED */
static void
vnic_m_stop(void *arg)
{
}

/* ARGSUSED */
static int
vnic_m_promisc(void *arg, boolean_t on)
{
	return (0);
}

/* ARGSUSED */
static int
vnic_m_multicst(void *arg, boolean_t add, const uint8_t *addrp)
{
	return (0);
}

static int
vnic_m_unicst(void *arg, const uint8_t *macaddr)
{
	vnic_t *vnic = arg;

	return (mac_vnic_unicast_set(vnic->vn_mch, macaddr));
}

/*
 * Callback functions for set/get of properties
 */
/*ARGSUSED*/
static int
vnic_m_setprop(void *m_driver, const char *pr_name, mac_prop_id_t pr_num,
    uint_t pr_valsize, const void *pr_val)
{
	int 		err = ENOTSUP;
	vnic_t		*vn = m_driver;

	/* allow setting MTU only on an etherstub */
	if (vn->vn_link_id != DATALINK_INVALID_LINKID)
		return (err);

	switch (pr_num) {
	case MAC_PROP_MTU: {
		uint32_t	mtu;

		if (pr_valsize < sizeof (mtu)) {
			err = EINVAL;
			break;
		}
		bcopy(pr_val, &mtu, sizeof (mtu));
		if (mtu < ANCHOR_VNIC_MIN_MTU || mtu > ANCHOR_VNIC_MAX_MTU) {
			err = EINVAL;
			break;
		}
		err = mac_maxsdu_update(vn->vn_mh, mtu);
		break;
	}
	default:
		break;
	}
	return (err);
}

/*ARGSUSED*/
static int
vnic_m_getprop(void *m_driver, const char *pr_name, mac_prop_id_t pr_num,
    uint_t pr_flags, uint_t pr_valsize, void *pr_val, uint_t *perm)
{
	mac_propval_range_t 	range;
	vnic_t			*vn = m_driver;
	int 			err = ENOTSUP;

	/* MTU setting allowed only on an etherstub */
	if (vn->vn_link_id != DATALINK_INVALID_LINKID)
		return (err);

	switch (pr_num) {
	case MAC_PROP_MTU:
		if (!(pr_flags & MAC_PROP_POSSIBLE))
			return (ENOTSUP);
		if (pr_valsize < sizeof (mac_propval_range_t))
			return (EINVAL);
		range.mpr_count = 1;
		range.mpr_type = MAC_PROPVAL_UINT32;
		range.range_uint32[0].mpur_min = ANCHOR_VNIC_MIN_MTU;
		range.range_uint32[0].mpur_max = ANCHOR_VNIC_MAX_MTU;
		bcopy(&range, pr_val, sizeof (range));
		return (0);
	default:
		break;
	}

	return (err);
}

int
vnic_info(vnic_info_t *info)
{
	vnic_t		*vnic;
	int		err;

	rw_enter(&vnic_lock, RW_WRITER);

	err = mod_hash_find(vnic_hash, VNIC_HASH_KEY(info->vn_vnic_id),
	    (mod_hash_val_t *)&vnic);
	if (err != 0) {
		rw_exit(&vnic_lock);
		return (ENOENT);
	}

	info->vn_link_id = vnic->vn_link_id;
	info->vn_mac_addr_type = vnic->vn_addr_type;
	info->vn_mac_len = vnic->vn_addr_len;
	bcopy(vnic->vn_addr, info->vn_mac_addr, MAXMACADDRLEN);
	info->vn_mac_slot = vnic->vn_slot_id;
	info->vn_mac_prefix_len = 0;
	info->vn_vid = vnic->vn_vid;
	info->vn_force = vnic->vn_force;

	bzero(&info->vn_resource_props, sizeof (mac_resource_props_t));
	if (vnic->vn_mch != NULL)
		mac_resource_ctl_get(vnic->vn_mch, &info->vn_resource_props);

	rw_exit(&vnic_lock);
	return (0);
}

static void
vnic_notify_cb(void *arg, mac_notify_type_t type)
{
	vnic_t *vnic = arg;

	/*
	 * Do not deliver notifications if the vnic is not fully initialized
	 * or is in process of being torn down.
	 */
	if (!vnic->vn_enabled)
		return;

	switch (type) {
	case MAC_NOTE_UNICST:
		/*
		 * Only the VLAN VNIC needs to be notified with primary MAC
		 * address change.
		 */
		if (vnic->vn_addr_type != VNIC_MAC_ADDR_TYPE_PRIMARY)
			return;

		/*  the unicast MAC address value */
		mac_unicast_primary_get(vnic->vn_lower_mh, vnic->vn_addr);

		/* notify its upper layer MAC about MAC address change */
		mac_unicst_update(vnic->vn_mh, (const uint8_t *)vnic->vn_addr);
		break;

	case MAC_NOTE_LINK:
		mac_link_update(vnic->vn_mh,
		    mac_client_stat_get(vnic->vn_mch, MAC_STAT_LINK_STATE));
		break;

	default:
		break;
	}
}