xen/io/xnbo.c

	xnbo.c revision 193974072f41a843678abf5f61979c748687e66b
/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Xen network backend - mac client edition.
 *
 * A driver that sits above an existing GLDv3/Nemo MAC driver and
 * relays packets to/from that driver from/to a guest domain.
 */

#include "xnb.h"

#include <sys/sunddi.h>
#include <sys/modctl.h>
#include <sys/strsubr.h>
#include <sys/mac.h>
#include <net/if.h>
#include <sys/dlpi.h>
#include <sys/pattr.h>
#include <xen/sys/xenbus_impl.h>
#include <xen/sys/xendev.h>

typedef struct xnbo {
    mac_handle_t        o_mh;
    mac_rx_handle_t     o_mrh;
    const mac_txinfo_t  *o_mtx;
    mac_notify_handle_t o_mnh;
    boolean_t       o_running;
    boolean_t       o_promiscuous;
    uint32_t        o_hcksum_capab;
} xnbo_t;

static void xnbo_close_mac(xnbo_t *);

/*
 * Packets from the peer come here.  We pass them to the mac device.
 */
static void
xnbo_to_mac(xnb_t *xnbp, mblk_t *mp)
{
    xnbo_t *xnbop = xnbp->xnb_flavour_data;

    ASSERT(mp != NULL);

    if (!xnbop->o_running) {
        xnbp->xnb_stat_tx_too_early++;
        goto fail;
    }

    mp = xnbop->o_mtx->mt_fn(xnbop->o_mtx->mt_arg, mp);

    if (mp != NULL) {
        xnbp->xnb_stat_mac_full++;
        goto fail;
    }

    return;

fail:
    freemsgchain(mp);
}

static mblk_t *
xnbo_cksum_from_peer(xnb_t *xnbp, mblk_t *mp, uint16_t flags)
{
    xnbo_t *xnbop = xnbp->xnb_flavour_data;

    ASSERT(mp->b_next == NULL);

    if ((flags & NETTXF_csum_blank) != 0) {
        /*
         * It would be nice to ASSERT that xnbp->xnb_cksum_offload
         * is TRUE here, but some peers insist on assuming
         * that it is available even when they have been told
         * otherwise.
         *
         * The checksum in the packet is blank.  Determine
         * whether we can do hardware offload and, if so,
         * update the flags on the mblk according.  If not,
         * calculate and insert the checksum using software.
         */
        mp = xnb_process_cksum_flags(xnbp, mp,
            xnbop->o_hcksum_capab);
    }

    return (mp);
}

static uint16_t
xnbo_cksum_to_peer(xnb_t *xnbp, mblk_t *mp)
{
    uint16_t r = 0;

    /*
     * We might also check for HCK_PARTIALCKSUM here and,
     * providing that the partial checksum covers the TCP/UDP
     * payload, return NETRXF_data_validated.
     *
     * It seems that it's probably not worthwhile, as even MAC
     * devices which advertise HCKSUM_INET_PARTIAL in their
     * capabilities tend to use HCK_FULLCKSUM on the receive side
     * - they are actually saying that in the output path the
     * caller must use HCK_PARTIALCKSUM.
     */

    if (xnbp->xnb_cksum_offload) {
        uint32_t pflags, csum;

        /*
         * XXPV dme: Pull in improved hcksum_retrieve() from
         * Crossbow, which gives back the csum in the seventh
         * argument for HCK_FULLCKSUM.
         */
        hcksum_retrieve(mp, NULL, NULL, NULL, NULL,
            NULL, NULL, &pflags);
        csum = DB_CKSUM16(mp);

        /*
         * If the MAC driver has asserted that the checksum is
         * good, let the peer know.
         */
        if (((pflags & HCK_FULLCKSUM) != 0) &&
            (((pflags & HCK_FULLCKSUM_OK) != 0) ||
            (csum == 0xffff)))
            r |= NETRXF_data_validated;
    }

    return (r);
}

/*
 * Packets from the mac device come here.  We pass them to the peer.
 */
/*ARGSUSED*/
static void
xnbo_from_mac(void *arg, mac_resource_handle_t mrh, mblk_t *mp)
{
    xnb_t *xnbp = arg;

    mp = xnb_copy_to_peer(xnbp, mp);

    if (mp != NULL)
        freemsgchain(mp);
}

/*
 * Packets from the mac device come here. We pass them to the peer if
 * the destination mac address matches or it's a multicast/broadcast
 * address.
 */
/*ARGSUSED*/
static void
xnbo_from_mac_filter(void *arg, mac_resource_handle_t mrh, mblk_t *mp)
{
    xnb_t *xnbp = arg;
    xnbo_t *xnbop = xnbp->xnb_flavour_data;
    mblk_t *next, *keep, *keep_head, *free, *free_head;

    keep = keep_head = free = free_head = NULL;

#define ADD(list, bp)               \
    if (list != NULL)           \
        list->b_next = bp;      \
    else                    \
        list##_head = bp;       \
    list = bp;

    for (; mp != NULL; mp = next) {
        mac_header_info_t hdr_info;

        next = mp->b_next;
        mp->b_next = NULL;

        if (mac_header_info(xnbop->o_mh, mp, &hdr_info) != 0) {
            ADD(free, mp);
            continue;
        }

        if ((hdr_info.mhi_dsttype == MAC_ADDRTYPE_BROADCAST) ||
            (hdr_info.mhi_dsttype == MAC_ADDRTYPE_MULTICAST)) {
            ADD(keep, mp);
            continue;
        }

        if (bcmp(hdr_info.mhi_daddr, xnbp->xnb_mac_addr,
            sizeof (xnbp->xnb_mac_addr)) == 0) {
            ADD(keep, mp);
            continue;
        }

        ADD(free, mp);
    }
#undef  ADD

    if (keep_head != NULL)
        xnbo_from_mac(xnbp, mrh, keep_head);

    if (free_head != NULL)
        freemsgchain(free_head);
}

static void
xnbo_notify(void *arg, mac_notify_type_t type)
{
    xnb_t *xnbp = arg;
    xnbo_t *xnbop = xnbp->xnb_flavour_data;

    switch (type) {
    case MAC_NOTE_PROMISC:
        xnbop->o_mtx = mac_tx_get(xnbop->o_mh);
        break;
    }
}

static boolean_t
xnbo_open_mac(xnb_t *xnbp, char *mac)
{
    xnbo_t *xnbop = xnbp->xnb_flavour_data;
    int err, need_rx_filter, need_setphysaddr, need_promiscuous;
    const mac_info_t *mi;
    char *xsname;
    void (*rx_fn)(void *, mac_resource_handle_t, mblk_t *);
    uint_t max_sdu;

    xsname = xvdi_get_xsname(xnbp->xnb_devinfo);

    if ((err = mac_open_by_linkname(mac, &xnbop->o_mh)) != 0) {
        cmn_err(CE_WARN, "xnbo_open_mac: "
            "cannot open mac for link %s (%d)", mac, err);
        return (B_FALSE);
    }
    ASSERT(xnbop->o_mh != NULL);

    mi = mac_info(xnbop->o_mh);
    ASSERT(mi != NULL);

    if (mi->mi_media != DL_ETHER) {
        cmn_err(CE_WARN, "xnbo_open_mac: "
            "device is not DL_ETHER (%d)", mi->mi_media);
        xnbo_close_mac(xnbop);
        return (B_FALSE);
    }
    if (mi->mi_media != mi->mi_nativemedia) {
        cmn_err(CE_WARN, "xnbo_open_mac: "
            "device media and native media mismatch (%d != %d)",
            mi->mi_media, mi->mi_nativemedia);
        xnbo_close_mac(xnbop);
        return (B_FALSE);
    }

    mac_sdu_get(xnbop->o_mh, NULL, &max_sdu);
    if (max_sdu > XNBMAXPKT) {
        cmn_err(CE_WARN, "xnbo_open_mac: mac device SDU too big (%d)",
            max_sdu);
        xnbo_close_mac(xnbop);
        return (B_FALSE);
    }

    xnbop->o_mnh = mac_notify_add(xnbop->o_mh, xnbo_notify, xnbp);
    ASSERT(xnbop->o_mnh != NULL);

    /*
     * Should the receive path filter packets from the downstream
     * NIC before passing them to the peer? The default is "no".
     */
    if (xenbus_scanf(XBT_NULL, xsname,
        "SUNW-need-rx-filter", "%d", &need_rx_filter) != 0)
        need_rx_filter = 0;
    if (need_rx_filter > 0)
        rx_fn = xnbo_from_mac_filter;
    else
        rx_fn = xnbo_from_mac;

    xnbop->o_mrh = mac_rx_add(xnbop->o_mh, rx_fn, xnbp);
    ASSERT(xnbop->o_mrh != NULL);

    xnbop->o_mtx = mac_tx_get(xnbop->o_mh);
    ASSERT(xnbop->o_mtx != NULL);

    if (!mac_capab_get(xnbop->o_mh, MAC_CAPAB_HCKSUM,
        &xnbop->o_hcksum_capab))
        xnbop->o_hcksum_capab = 0;

    /*
     * Should we set the physical address of the underlying NIC
     * to match that assigned to the peer? The default is "no".
     */
    if (xenbus_scanf(XBT_NULL, xsname,
        "SUNW-need-set-physaddr", "%d", &need_setphysaddr) != 0)
        need_setphysaddr = 0;
    if (need_setphysaddr > 0) {
        struct ether_addr ea;

        err = mac_unicst_set(xnbop->o_mh, xnbp->xnb_mac_addr);
        /* Warn, but continue on. */
        if (err != 0) {
            bcopy(xnbp->xnb_mac_addr, ea.ether_addr_octet,
                ETHERADDRL);
            cmn_err(CE_WARN, "xnbo_open_mac: "
                "cannot set MAC address of %s to "
                "%s: %d", mac, ether_sprintf(&ea),
                err);
        }
    }

    /*
     * Should we set the underlying NIC into promiscuous mode? The
     * default is "no".
     */
    if (xenbus_scanf(XBT_NULL, xsname,
        "SUNW-need-promiscuous", "%d", &need_promiscuous) != 0)
        need_promiscuous = 0;
    if (need_promiscuous > 0) {
        err = mac_promisc_set(xnbop->o_mh, B_TRUE, MAC_DEVPROMISC);
        if (err != 0) {
            cmn_err(CE_WARN, "xnbo_open_mac: "
                "cannot enable promiscuous mode of %s: %d",
                mac, err);
            xnbo_close_mac(xnbop);
            return (B_FALSE);
        }
        xnbop->o_promiscuous = B_TRUE;
    }

    if ((err = mac_start(xnbop->o_mh)) != 0) {
        cmn_err(CE_WARN, "xnbo_open_mac: "
            "cannot start mac device (%d)", err);
        xnbo_close_mac(xnbop);
        return (B_FALSE);
    }
    xnbop->o_running = B_TRUE;

    return (B_TRUE);
}

/*
 * xnb calls back here when the user-level hotplug code reports that
 * the hotplug has successfully completed. For this flavour that means
 * that the underlying MAC device that we will use is ready to be
 * opened.
 */
static boolean_t
xnbo_hotplug(xnb_t *xnbp)
{
    char *xsname;
    char mac[LIFNAMSIZ];

    xsname = xvdi_get_xsname(xnbp->xnb_devinfo);
    if (xenbus_scanf(XBT_NULL, xsname, "nic", "%s", mac) != 0) {
        cmn_err(CE_WARN, "xnbo_hotplug: "
            "cannot read nic name from %s", xsname);
        return (B_FALSE);
    }

    return (xnbo_open_mac(xnbp, mac));
}

static void
xnbo_close_mac(xnbo_t *xnbop)
{
    if (xnbop->o_mh == NULL)
        return;

    if (xnbop->o_running) {
        mac_stop(xnbop->o_mh);
        xnbop->o_running = B_FALSE;
    }

    if (xnbop->o_promiscuous) {
        (void) mac_promisc_set(xnbop->o_mh, B_FALSE,
            MAC_DEVPROMISC);
        xnbop->o_promiscuous = B_FALSE;
    }

    xnbop->o_mtx = NULL;

    if (xnbop->o_mrh != NULL) {
        mac_rx_remove(xnbop->o_mh, xnbop->o_mrh, B_TRUE);
        xnbop->o_mrh = NULL;
    }

    if (xnbop->o_mnh != NULL) {
        mac_notify_remove(xnbop->o_mh, xnbop->o_mnh);
        xnbop->o_mnh = NULL;
    }

    mac_close(xnbop->o_mh);
    xnbop->o_mh = NULL;
}

/*
 * xnb calls back here when we successfully synchronize with the
 * driver in the guest domain. In this flavour there is nothing to do as
 * we open the underlying MAC device on successful hotplug completion.
 */
/*ARGSUSED*/
static void
xnbo_connected(xnb_t *xnbp)
{
}

/*
 * xnb calls back here when the driver in the guest domain has closed
 * down the inter-domain connection. We close the underlying MAC device.
 */
static void
xnbo_disconnected(xnb_t *xnbp)
{
    xnbo_close_mac(xnbp->xnb_flavour_data);
}

static int
xnbo_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
    static xnb_flavour_t flavour = {
        xnbo_to_mac, xnbo_connected, xnbo_disconnected, xnbo_hotplug,
        xnbo_cksum_from_peer, xnbo_cksum_to_peer,
    };
    xnbo_t *xnbop;

    switch (cmd) {
    case DDI_ATTACH:
        break;
    case DDI_RESUME:
        return (DDI_SUCCESS);
    default:
        return (DDI_FAILURE);
    }

    xnbop = kmem_zalloc(sizeof (*xnbop), KM_SLEEP);

    xnbop->o_mh = NULL;
    xnbop->o_mrh = NULL;
    xnbop->o_mtx = NULL;
    xnbop->o_running = B_FALSE;
    xnbop->o_hcksum_capab = 0;

    if (xnb_attach(dip, &flavour, xnbop) != DDI_SUCCESS) {
        kmem_free(xnbop, sizeof (*xnbop));
        return (DDI_FAILURE);
    }

    return (DDI_SUCCESS);
}

static int
xnbo_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
    xnb_t *xnbp = ddi_get_driver_private(dip);
    xnbo_t *xnbop = xnbp->xnb_flavour_data;

    switch (cmd) {
    case DDI_DETACH:
        break;
    case DDI_SUSPEND:
        return (DDI_SUCCESS);
    default:
        return (DDI_FAILURE);
    }

    mutex_enter(&xnbp->xnb_tx_lock);
    mutex_enter(&xnbp->xnb_rx_lock);

    if (!xnbp->xnb_detachable || xnbp->xnb_connected ||
        (xnbp->xnb_tx_buf_count > 0)) {
        mutex_exit(&xnbp->xnb_rx_lock);
        mutex_exit(&xnbp->xnb_tx_lock);

        return (DDI_FAILURE);
    }

    mutex_exit(&xnbp->xnb_rx_lock);
    mutex_exit(&xnbp->xnb_tx_lock);

    xnbo_close_mac(xnbop);
    kmem_free(xnbop, sizeof (*xnbop));

    xnb_detach(dip);

    return (DDI_SUCCESS);
}

static struct cb_ops cb_ops = {
    nulldev,        /* open */
    nulldev,        /* close */
    nodev,          /* strategy */
    nodev,          /* print */
    nodev,          /* dump */
    nodev,          /* read */
    nodev,          /* write */
    nodev,          /* ioctl */
    nodev,          /* devmap */
    nodev,          /* mmap */
    nodev,          /* segmap */
    nochpoll,       /* poll */
    ddi_prop_op,        /* cb_prop_op */
    0,          /* streamtab  */
    D_NEW | D_MP | D_64BIT  /* Driver compatibility flag */
};

static struct dev_ops ops = {
    DEVO_REV,       /* devo_rev */
    0,          /* devo_refcnt  */
    nulldev,        /* devo_getinfo */
    nulldev,        /* devo_identify */
    nulldev,        /* devo_probe */
    xnbo_attach,        /* devo_attach */
    xnbo_detach,        /* devo_detach */
    nodev,          /* devo_reset */
    &cb_ops,        /* devo_cb_ops */
    (struct bus_ops *)0,    /* devo_bus_ops */
    NULL,           /* devo_power */
    ddi_quiesce_not_needed,     /* devo_quiesce */
};

static struct modldrv modldrv = {
    &mod_driverops, "xnbo driver", &ops,
};

static struct modlinkage modlinkage = {
    MODREV_1, &modldrv, NULL
};

int
_init(void)
{
    return (mod_install(&modlinkage));
}

int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}

int
_fini(void)
{
    return (mod_remove(&modlinkage));
}