libldom/sparc/ldmsvcs_utils.c

	ldmsvcs_utils.c revision 3dc13b01e6ccde35cc4e663e261cdcbed0070e48
/*
 * 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 <stdlib.h>
#include <stdio.h>

#include <strings.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <umem.h>
#include <alloca.h>
#include <sys/processor.h>
#include <poll.h>
#include <pthread.h>
#include <signal.h>
#include <values.h>
#include <libscf.h>

#include <ctype.h>

#include "ldmsvcs_utils.h"
#include "ldom_alloc.h"

#define ASSERT(cnd) \
    ((void) ((cnd) || ((void) fprintf(stderr, \
        "assertion failure in %s:%d: %s\n", \
        __FILE__, __LINE__, #cnd), 0)))

#define FDS_VLDC \
    "/devices/virtual-devices@100/channel-devices@200/" \
    "/virtual-channel-client@1:ldmfma"

/* allow timeouts in sec that are nearly forever but small enough for an int */
#define LDM_TIMEOUT_CEILING (MAXINT / 2)

#define MIN(x, y)   ((x) < (y) ? (x) : (y))

/*
 * functions in this file are for version 1.0 of FMA domain services
 */
static ds_ver_t ds_vers[] = {
    { 1, 0 }
};

#define DS_NUM_VER  (sizeof (ds_vers) / sizeof (ds_ver_t))

/*
 * information for each channel
 */
struct ldmsvcs_info {
    pthread_mutex_t mt;
    pthread_cond_t cv;
    fds_channel_t fds_chan;
    fds_reg_svcs_t fmas_svcs;
    int cv_twait;
};

/*
 * struct listdata_s and struct poller_s are used to maintain the state of
 * the poller thread.  this thread is used to manage incoming messages and
 * pass those messages onto the correct requesting thread.  see the "poller
 * functions" section for more details.
 */
struct listdata_s {
    enum {
        UNUSED,
        PENDING,
        ARRIVED
    } status;
    uint64_t req_num;
    int fd;
    size_t datalen;
};

static struct poller_s {
    pthread_mutex_t mt;
    pthread_cond_t cv;
    pthread_t polling_tid;
    int doreset;
    int doexit;
    int nclients;
    struct listdata_s **list;
    int list_len;
    int pending_count;
} pollbase = {
    PTHREAD_MUTEX_INITIALIZER,
    PTHREAD_COND_INITIALIZER,
    0,
    1,
    0,
    0,
    NULL,
    0,
    0
};


static struct ldmsvcs_info *channel_init(struct ldom_hdl *lhp);
static int channel_openreset(struct ldmsvcs_info *lsp);
static int read_msg(struct ldmsvcs_info *lsp);

static int
get_smf_int_val(char *prop_nm, int min, int max, int default_val)
{
    scf_simple_prop_t   *prop;      /* SMF property */
    int64_t         *valp;      /* prop value ptr */
    int64_t         val;        /* prop value to return */

    val = default_val;
    if ((prop = scf_simple_prop_get(NULL, LDM_SVC_NM, LDM_PROP_GROUP_NM,
        prop_nm)) != NULL) {
        if ((valp = scf_simple_prop_next_integer(prop)) != NULL) {
            val = *valp;
            if (val < min)
                val = min;
            else if (val > max)
                val = max;
        }
        scf_simple_prop_free(prop);
    }
    return ((int)val);
}

static void
channel_close(struct ldmsvcs_info *lsp)
{
    (void) pthread_mutex_lock(&lsp->mt);

    if (lsp->fds_chan.state == CHANNEL_OPEN ||
        lsp->fds_chan.state == CHANNEL_READY) {
        (void) close(lsp->fds_chan.fd);
        lsp->cv_twait = get_smf_int_val(LDM_INIT_TO_PROP_NM,
            0, LDM_TIMEOUT_CEILING, LDM_INIT_WAIT_TIME);
        lsp->fds_chan.state = CHANNEL_CLOSED;
    }

    (void) pthread_mutex_unlock(&lsp->mt);
}

/*
 * read size bytes of data from a streaming fd into buf
 */
static int
read_stream(int fd, void *buf, size_t size)
{
    pollfd_t pollfd;
    ssize_t rv;
    size_t data_left;
    ptrdiff_t currentp;

    pollfd.events = POLLIN;
    pollfd.revents = 0;
    pollfd.fd = fd;

    currentp = (ptrdiff_t)buf;
    data_left = size;

    /*
     * data may come in bits and pieces
     */
    do {
        if ((rv = read(fd, (void *)currentp, data_left)) < 0) {
            if (errno == EAGAIN && poll(&pollfd, 1, -1) > 0)
                continue;   /* retry */
            else
                return (1);
        }

        data_left -= rv;
        currentp += rv;
    } while (data_left > 0);

    return (0);
}


/*
 * poller functions
 *
 * at init time, a thread is created for the purpose of monitoring incoming
 * messages and doing one of the following:
 *
 * 1. doing the initial handshake and version negotiation
 *
 * 2. handing incoming data off to the requesting thread (which is an fmd
 * module or scheme thread)
 */
static int
poller_handle_data(int fd, size_t payloadsize)
{
    uint64_t *req_num;
    void *pr;
    size_t prlen;
    int i;

    prlen = sizeof (ds_data_handle_t) + sizeof (uint64_t);

    if (payloadsize < prlen)
        return (1);

    pr = alloca(prlen);

    if (read_stream(fd, pr, prlen) != 0)
        return (1);

    req_num = (uint64_t *)((ptrdiff_t)pr + sizeof (ds_data_handle_t));

    (void) pthread_mutex_lock(&pollbase.mt);

    for (i = 0; i < pollbase.list_len; i++) {
        if (pollbase.list[i]->req_num == *req_num) {
            ASSERT(pollbase.list[i]->status == PENDING);

            pollbase.list[i]->status = ARRIVED;
            pollbase.list[i]->fd = fd;
            pollbase.list[i]->datalen = payloadsize - prlen;

            pollbase.pending_count--;
            (void) pthread_cond_broadcast(&pollbase.cv);
            break;
        }
    }

    /*
     * now wait for receiving thread to read in the data
     */
    if (i < pollbase.list_len) {
        while (pollbase.list[i]->status == ARRIVED)
            (void) pthread_cond_wait(&pollbase.cv, &pollbase.mt);
    }

    (void) pthread_mutex_unlock(&pollbase.mt);

    return (0);
}


/*
 * note that this function is meant to handle only DS_DATA messages
 */
static int
poller_recv_data(struct ldom_hdl *lhp, uint64_t req_num, int index,
        void **resp, size_t *resplen)
{
    struct timespec twait;
    int ier;

    ier = 0;
    twait.tv_sec = time(NULL) + lhp->lsinfo->cv_twait;
    twait.tv_nsec = 0;

    (void) pthread_mutex_lock(&pollbase.mt);

    ASSERT(pollbase.list[index]->req_num == req_num);

    while (pollbase.list[index]->status == PENDING &&
        pollbase.doreset == 0 && ier == 0)
        ier = pthread_cond_timedwait(&pollbase.cv, &pollbase.mt,
            &twait);

    if (ier == 0) {
        if (pollbase.doreset == 0) {
            ASSERT(pollbase.list[index]->status == ARRIVED);

            /*
             * need to add req_num to beginning of resp
             */
            *resplen = pollbase.list[index]->datalen +
                sizeof (uint64_t);
            *resp = lhp->allocp(*resplen);
            *((uint64_t *)*resp) = req_num;

            if (read_stream(pollbase.list[index]->fd,
                (void *)((ptrdiff_t)*resp + sizeof (uint64_t)),
                *resplen - sizeof (uint64_t)) != 0)
                ier = ETIMEDOUT;

            pollbase.list[index]->status = UNUSED;
            pollbase.list[index]->req_num = 0;
            (void) pthread_cond_broadcast(&pollbase.cv);
        } else {
            if (--(pollbase.pending_count) == 0)
                (void) pthread_cond_broadcast(&pollbase.cv);
        }
    }

    (void) pthread_mutex_unlock(&pollbase.mt);

    ASSERT(ier == 0 || ier == ETIMEDOUT);

    return (ier);
}


static void
poller_add_client(void)
{
    (void) pthread_mutex_lock(&pollbase.mt);
    pollbase.nclients++;
    (void) pthread_mutex_unlock(&pollbase.mt);
}


static void
poller_remove_client(void)
{
    (void) pthread_mutex_lock(&pollbase.mt);
    pollbase.nclients--;
    ASSERT(pollbase.nclients >= 0);
    (void) pthread_mutex_unlock(&pollbase.mt);
}


static int
poller_add_pending(uint64_t req_num)
{
    int newlen, index, i, j;

    (void) pthread_mutex_lock(&pollbase.mt);
    pollbase.pending_count++;

    for (j = 0, index = -1; j < 2 && index == -1; j++) {
        for (i = 0; i < pollbase.list_len; i++) {
            if (pollbase.list[i]->status == UNUSED) {
                pollbase.list[i]->status = PENDING;
                pollbase.list[i]->req_num = req_num;
                pollbase.list[i]->datalen = 0;
                index = i;
                break;
            }
        }

        if (index == -1) {
            struct listdata_s **newlist, **oldlist;

            /*
             * get to this point if list is not long enough.
             * check for a runaway list.  since requests are
             * synchronous (clients send a request and need to
             * wait for the result before returning) the size
             * of the list cannot be much more than the number
             * of clients.
             */
            ASSERT(pollbase.list_len < pollbase.nclients + 1);

            newlen = pollbase.list_len + 5;
            newlist = ldom_alloc(newlen *
                sizeof (struct listdata_s *));

            for (i = 0; i < pollbase.list_len; i++)
                newlist[i] = pollbase.list[i];

            oldlist = pollbase.list;
            pollbase.list = newlist;
            ldom_free(oldlist, pollbase.list_len *
                sizeof (struct listdata_s *));

            for (i = pollbase.list_len; i < newlen; i++) {
                pollbase.list[i] =
                    ldom_alloc(sizeof (struct listdata_s));
                pollbase.list[i]->status = UNUSED;
            }

            pollbase.list_len = newlen;
        }
    }

    (void) pthread_mutex_unlock(&pollbase.mt);
    ASSERT(index != -1);

    return (index);
}


static void
poller_delete_pending(uint64_t req_num, int index)
{
    (void) pthread_mutex_lock(&pollbase.mt);

    ASSERT(pollbase.list[index]->req_num == req_num);
    pollbase.list[index]->status = UNUSED;

    if (--(pollbase.pending_count) == 0 && pollbase.doreset == 1)
        (void) pthread_cond_broadcast(&pollbase.cv);

    (void) pthread_mutex_unlock(&pollbase.mt);
}


static void
poller_shutdown(boolean_t wait)
{
    (void) pthread_mutex_lock(&pollbase.mt);

    pollbase.doexit = 1;

    (void) pthread_mutex_unlock(&pollbase.mt);

    if (wait == B_TRUE) {
        /* stop the poller thread  and wait for it to end */
        (void) pthread_kill(pollbase.polling_tid, SIGTERM);
        (void) pthread_join(pollbase.polling_tid, NULL);
    }
}


/*
 * perform the polling of incoming messages.  manage any resets (usually
 * due to one end of the connection being closed) as well as exit
 * conditions.
 */
static void *
poller_loop(void *arg)
{
    struct ldmsvcs_info *lsp;
    pollfd_t pollfd;
    int ier;

    lsp = (struct ldmsvcs_info *)arg;

    for (;;) {
        (void) pthread_mutex_lock(&pollbase.mt);

        if (pollbase.doexit) {
            (void) pthread_mutex_unlock(&pollbase.mt);
            break;
        }

        if (pollbase.doreset) {
            int i;

            while (pollbase.pending_count > 0)
                (void) pthread_cond_wait(&pollbase.cv,
                    &pollbase.mt);

            ASSERT(pollbase.pending_count == 0);
            for (i = 0; i < pollbase.list_len; i++)
                pollbase.list[i]->status = UNUSED;

            pollbase.doreset = 0;
        }
        (void) pthread_mutex_unlock(&pollbase.mt);

        if ((ier = channel_openreset(lsp)) == 1) {
            continue;
        } else if (ier == 2) {
            /*
             * start exit preparations
             */
            poller_shutdown(B_FALSE);
            continue;
        }

        pollfd.events = POLLIN;
        pollfd.revents = 0;
        pollfd.fd = lsp->fds_chan.fd;

        if (poll(&pollfd, 1, -1) <= 0 || read_msg(lsp) != 0) {
            /*
             * read error and/or fd got closed
             */
            (void) pthread_mutex_lock(&pollbase.mt);
            pollbase.doreset = 1;
            (void) pthread_mutex_unlock(&pollbase.mt);

            channel_close(lsp);
        }
    }

    return (NULL);
}


/*
 * create the polling thread
 */
static int
poller_init(struct ldmsvcs_info *lsp)
{
    int rc = 0;

    (void) pthread_mutex_lock(&pollbase.mt);

    if (pollbase.polling_tid == 0) {
        pthread_attr_t *attr = NULL;

        /*
         * create a joinable polling thread for receiving messages
         */
        if (pthread_create(&pollbase.polling_tid, attr,
            poller_loop, lsp) != 0)
            rc = 1;
    }

    (void) pthread_mutex_unlock(&pollbase.mt);

    return (rc);
}

/*
 * Cleanup the polling thread
 */
static void
poller_fini(void)
{
    int i;

    /* stop the poller thread */
    poller_shutdown(B_TRUE);

    (void) pthread_mutex_lock(&pollbase.mt);

    /* Free up the list of outstanding requests */
    if (pollbase.list != NULL) {
        for (i = 0; i < pollbase.list_len; i++) {
            if (pollbase.list[i]) {
                ldom_free(pollbase.list[i],
                    sizeof (struct listdata_s));
            }
        }
        ldom_free(pollbase.list, pollbase.list_len *
            sizeof (struct listdata_s *));
        pollbase.list = NULL;
        pollbase.list_len = 0;
    }

    (void) pthread_mutex_unlock(&pollbase.mt);
}

/*
 * utilities for message handlers
 */
static int
fds_send(struct ldmsvcs_info *lsp, void *msg, size_t msglen)
{
    static pthread_mutex_t mt = PTHREAD_MUTEX_INITIALIZER;

    (void) pthread_mutex_lock(&mt);

    if (write(lsp->fds_chan.fd, msg, msglen) != msglen) {
        channel_close(lsp);
        (void) pthread_mutex_unlock(&mt);
        return (ETIMEDOUT);
    }

    (void) pthread_mutex_unlock(&mt);
    return (0);
}


/*
 * Find the max and min version supported
 */
static void
fds_min_max_versions(uint16_t *min_major, uint16_t *max_major)
{
    int i;

    *min_major = ds_vers[0].major;
    *max_major = *min_major;

    for (i = 1; i < DS_NUM_VER; i++) {
        if (ds_vers[i].major < *min_major)
            *min_major = ds_vers[i].major;

        if (ds_vers[i].major > *max_major)
            *max_major = ds_vers[i].major;
    }
}

/*
 * check whether the major and minor numbers requested by remote ds client
 * can be satisfied.  if the requested major is supported, true is
 * returned, and the agreed minor is returned in new_minor.  if the
 * requested major is not supported, the routine returns false, and the
 * closest major is returned in *new_major, upon which the ds client should
 * renegotiate.  the closest major is the just lower that the requested
 * major number.
 */
static boolean_t
fds_negotiate_version(uint16_t req_major, uint16_t *new_majorp,
    uint16_t *new_minorp)
{
    int i = 0;
    uint16_t major, lower_major;
    uint16_t min_major, max_major;
    boolean_t found_match = B_FALSE;

    fds_min_max_versions(&min_major, &max_major);

    /*
     * if the minimum version supported is greater than the version
     * requested, return the lowest version supported
     */
    if (min_major > req_major) {
        *new_majorp = min_major;
        return (B_FALSE);
    }

    /*
     * if the largest version supported is lower than the version
     * requested, return the largest version supported
     */
    if (max_major < req_major) {
        *new_majorp = max_major;
        return (B_FALSE);
    }

    /*
     * now we know that the requested version lies between the min and
     * max versions supported.  check if the requested major can be
     * found in supported versions.
     */
    lower_major = min_major;
    for (i = 0; i < DS_NUM_VER; i++) {
        major = ds_vers[i].major;
        if (major == req_major) {
            found_match = B_TRUE;
            *new_minorp = ds_vers[i].minor;
            *new_majorp = major;
            break;
        } else if ((major < req_major) && (major > lower_major))
            lower_major = major;
    }

    /*
     * If  no match is found, return the closest available number
     */
    if (!found_match)
        *new_majorp = lower_major;

    return (found_match);
}


/*
 * return 0 if service is added; 1 if service is a duplicate
 */
static int
fds_svc_add(struct ldmsvcs_info *lsp, ds_reg_req_t *req, int minor)
{
    fds_svc_t *svc;
    int i, rc;

    svc = NULL;
    for (i = 0; i < lsp->fmas_svcs.nsvcs; i++) {
        if (strcmp(lsp->fmas_svcs.tbl[i]->name, req->svc_id) == 0) {
            svc = lsp->fmas_svcs.tbl[i];
            break;
        }
    }

    if (svc == NULL)
        return (0); /* we don't need this service */

    (void) pthread_mutex_lock(&lsp->fmas_svcs.mt);

    /*
     * duplicate registration is OK --- we retain the previous entry
     * (which has not been unregistered anyway)
     */
    if (svc->state == DS_SVC_ACTIVE) {
        rc = 1;
    } else {
        svc->state = DS_SVC_ACTIVE;
        svc->hdl = req->svc_handle;
        svc->ver.major = req->major_vers;
        svc->ver.minor = minor;

        rc = 0;
        (void) pthread_cond_broadcast(&lsp->fmas_svcs.cv);
    }

    (void) pthread_mutex_unlock(&lsp->fmas_svcs.mt);

    return (rc);
}


static void
fds_svc_reset(struct ldmsvcs_info *lsp, int index)
{
    int i, start, end;

    if (index >= 0) {
        start = index;
        end = index + 1;
    } else {
        start = 0;
        end = lsp->fmas_svcs.nsvcs;
    }

    (void) pthread_mutex_lock(&lsp->fmas_svcs.mt);

    for (i = start; i < end; i++) {
        lsp->fmas_svcs.tbl[i]->hdl = 0;
        lsp->fmas_svcs.tbl[i]->state = DS_SVC_INVAL;
        lsp->fmas_svcs.tbl[i]->ver.major =
            ds_vers[DS_NUM_VER - 1].major;
        lsp->fmas_svcs.tbl[i]->ver.minor =
            ds_vers[DS_NUM_VER - 1].minor;
    }

    (void) pthread_mutex_unlock(&lsp->fmas_svcs.mt);
}


static int
fds_svc_remove(struct ldmsvcs_info *lsp, ds_svc_hdl_t svc_handle)
{
    int i;

    for (i = 0; i < lsp->fmas_svcs.nsvcs; i++) {
        if (lsp->fmas_svcs.tbl[i]->hdl == svc_handle) {
            fds_svc_reset(lsp, i);
            return (0);
        }
    }

    return (1);
}


/*
 * message handlers
 */
/*ARGSUSED*/
static void
ds_handle_msg_noop(struct ldmsvcs_info *lsp, void *buf, size_t len)
{
}

static void
ds_handle_init_req(struct ldmsvcs_info *lsp, void *buf, size_t len)
{
    ds_init_req_t *req;
    uint16_t new_major, new_minor;
    size_t msglen;

    req = (ds_init_req_t *)buf;

    /* sanity check the incoming message */
    if (len != sizeof (ds_init_req_t)) {
        channel_close(lsp);
        return;
    }

    /*
     * Check version info. ACK only if the major numbers exactly
     * match. The service entity can retry with a new minor
     * based on the response sent as part of the NACK.
     */
    if (fds_negotiate_version(req->major_vers, &new_major, &new_minor)) {
        ds_hdr_t *H;
        ds_init_ack_t *R;

        msglen = sizeof (ds_hdr_t) + sizeof (ds_init_ack_t);
        H = alloca(msglen);
        R = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));

        H->msg_type = DS_INIT_ACK;
        H->payload_len = sizeof (ds_init_ack_t);
        R->minor_vers = MIN(new_minor, req->minor_vers);

        if (fds_send(lsp, H, msglen) != 0)
            return;

        (void) pthread_mutex_lock(&lsp->mt);
        ASSERT(lsp->fds_chan.state == CHANNEL_OPEN);
        lsp->fds_chan.state = CHANNEL_READY;

        /*
         * Now the channel is ready after the handshake completes.
         * Reset the timeout to a smaller value for receiving messages
         * from the domain services.
         */
        lsp->cv_twait = get_smf_int_val(LDM_RUNNING_TO_PROP_NM,
            0, LDM_TIMEOUT_CEILING, LDM_RUNNING_WAIT_TIME);

        (void) pthread_mutex_unlock(&lsp->mt);
    } else {
        ds_hdr_t *H;
        ds_init_nack_t *R;

        msglen = sizeof (ds_hdr_t) + sizeof (ds_init_nack_t);
        H = alloca(msglen);
        R = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));

        H->msg_type = DS_INIT_NACK;
        H->payload_len = sizeof (ds_init_nack_t);
        R->major_vers = new_major;

        (void) fds_send(lsp, H, msglen);
        /*
         * do not update state; remote end may attempt to initiate
         * connection with a different version
         */
    }
}


/*ARGSUSED*/
static void
ds_handle_reg_req(struct ldmsvcs_info *lsp, void *buf, size_t len)
{
    ds_reg_req_t *req;
    char *msg;
    uint16_t new_major, new_minor;
    size_t msglen;
    int dup_svcreg = 0;

    req = (ds_reg_req_t *)buf;
    msg = (char *)req->svc_id;

    /*
     * Service must be NULL terminated
     */
    if (req->svc_id == NULL || strlen(req->svc_id) == 0 ||
        msg[strlen(req->svc_id)] != '\0') {
        channel_close(lsp);
        return;
    }

    if (fds_negotiate_version(req->major_vers, &new_major, &new_minor) &&
        (dup_svcreg = fds_svc_add(lsp, req,
        MIN(new_minor, req->minor_vers))) == 0) {

        /*
         * Check version info. ACK only if the major numbers
         * exactly match. The service entity can retry with a new
         * minor based on the response sent as part of the NACK.
         */
        ds_hdr_t *H;
        ds_reg_ack_t *R;

        msglen = sizeof (ds_hdr_t) + sizeof (ds_reg_ack_t);
        H = alloca(msglen);
        bzero(H, msglen);
        R = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));

        H->msg_type = DS_REG_ACK;
        H->payload_len = sizeof (ds_reg_ack_t);
        R->svc_handle = req->svc_handle;
        R->minor_vers = MIN(new_minor, req->minor_vers);

        (void) fds_send(lsp, H, msglen);
    } else {
        ds_hdr_t *H;
        ds_reg_nack_t *R;

        msglen = sizeof (ds_hdr_t) + sizeof (ds_reg_nack_t);
        H = alloca(msglen);
        bzero(H, msglen);
        R = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));

        H->msg_type = DS_REG_NACK;
        H->payload_len = sizeof (ds_reg_nack_t);
        R->svc_handle = req->svc_handle;
        R->major_vers = new_major;

        if (dup_svcreg)
            R->result = DS_REG_DUP;
        else
            R->result = DS_REG_VER_NACK;

        (void) fds_send(lsp, H, msglen);
    }
}


/*ARGSUSED*/
static void
ds_handle_unreg(struct ldmsvcs_info *lsp, void *buf, size_t len)
{
    ds_unreg_req_t *req;
    size_t msglen;

    req = (ds_unreg_req_t *)buf;

    if (fds_svc_remove(lsp, req->svc_handle) == 0) {
        ds_hdr_t *H;
        ds_unreg_ack_t *R;

        msglen = sizeof (ds_hdr_t) + sizeof (ds_unreg_ack_t);
        H = alloca(msglen);
        R = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));

        H->msg_type = DS_REG_ACK;
        H->payload_len = sizeof (ds_unreg_ack_t);
        R->svc_handle = req->svc_handle;

        (void) fds_send(lsp, H, msglen);
    } else {
        ds_hdr_t *H;
        ds_unreg_nack_t *R;

        msglen = sizeof (ds_hdr_t) + sizeof (ds_unreg_nack_t);
        H = alloca(msglen);
        R = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));

        H->msg_type = DS_REG_NACK;
        H->payload_len = sizeof (ds_unreg_nack_t);
        R->svc_handle = req->svc_handle;

        (void) fds_send(lsp, H, msglen);
    }
}


/*
 * Message handler lookup table (v1.0 only for now) Future
 * versions can add their own lookup table.
 */
typedef void (*ds_msg_handler_t)(struct ldmsvcs_info *lsp,
                void *buf, size_t len);

static const ds_msg_handler_t ds_msg_handlers[] = {
    ds_handle_init_req,     /* DS_INIT_REQ */
    ds_handle_msg_noop,     /* DS_INIT_ACK */
    ds_handle_msg_noop,     /* DS_INIT_NACK */
    ds_handle_reg_req,      /* DS_REG_REQ */
    ds_handle_msg_noop,     /* DS_REG_ACK */
    ds_handle_msg_noop,     /* DS_REG_NACK */
    ds_handle_unreg,        /* DS_UNREG */
    ds_handle_msg_noop,     /* DS_UNREG_ACK */
    ds_handle_msg_noop,     /* DS_UNREG_NACK */
    ds_handle_msg_noop,     /* DS_DATA */
    ds_handle_msg_noop      /* DS_NACK */
};


/*
 * message and service internal functions
 */
static void
fds_svc_alloc(struct ldmsvcs_info *lsp)
{
    int i;
    static char *name[] = { LDM_DS_NAME_CPU, LDM_DS_NAME_MEM,
            LDM_DS_NAME_PRI, LDM_DS_NAME_IOD, NULL };

    (void) pthread_mutex_init(&lsp->fmas_svcs.mt, NULL);
    (void) pthread_cond_init(&lsp->fmas_svcs.cv, NULL);

    for (lsp->fmas_svcs.nsvcs = 0; name[lsp->fmas_svcs.nsvcs] != NULL;
        lsp->fmas_svcs.nsvcs++)
        ;

    lsp->fmas_svcs.tbl = (fds_svc_t **)ldom_alloc(sizeof (fds_svc_t *) *
        lsp->fmas_svcs.nsvcs);

    for (i = 0; i < lsp->fmas_svcs.nsvcs; i++) {
        lsp->fmas_svcs.tbl[i] =
            (fds_svc_t *)ldom_alloc(sizeof (fds_svc_t));
        bzero(lsp->fmas_svcs.tbl[i], sizeof (fds_svc_t));
        lsp->fmas_svcs.tbl[i]->name = name[i];
    }
}


static fds_svc_t *
fds_svc_lookup(struct ldmsvcs_info *lsp, char *name)
{
    struct timespec twait;
    fds_svc_t *svc;
    int i, ier;

    if (pthread_mutex_lock(&lsp->fmas_svcs.mt) == EINVAL)
        return (NULL);  /* uninitialized or destroyed mutex */

    svc = NULL;
    for (i = 0; i < lsp->fmas_svcs.nsvcs; i++) {
        if (strcmp(lsp->fmas_svcs.tbl[i]->name, name) == 0) {
            svc = lsp->fmas_svcs.tbl[i];
            break;
        }
    }

    ASSERT(svc != NULL);

    if (svc->state == DS_SVC_INACTIVE) {
        /* service is not registered */
        ier = ETIMEDOUT;
    } else {
        ier = 0;
        twait.tv_sec = time(NULL) + lsp->cv_twait;
        twait.tv_nsec = 0;

        while (svc->state != DS_SVC_ACTIVE && ier == 0 &&
            lsp->fds_chan.state != CHANNEL_UNUSABLE)
            ier = pthread_cond_timedwait(&lsp->fmas_svcs.cv,
                &lsp->fmas_svcs.mt, &twait);

        /*
         * By now, the ds service should have registered already.
         * If it does not, ldmd probably does not support this service.
         * Then mark the service state as inactive.
         */
        if (ier == ETIMEDOUT) {
            svc->state = DS_SVC_INACTIVE;
        }
    }

    (void) pthread_mutex_unlock(&lsp->fmas_svcs.mt);

    if (ier == 0)
        return (svc);
    else
        return (NULL);
}


static uint64_t
fds_svc_req_num(void)
{
    static uint64_t req_num = 1;

    return (req_num++);
}


/*
 * return 0 if successful, 1 if otherwise
 */
static int
read_msg(struct ldmsvcs_info *lsp)
{
    ds_hdr_t header;
    void *msg_buf;

    /*
     * read the header
     */
    if (read_stream(lsp->fds_chan.fd, &header, sizeof (ds_hdr_t)) != 0)
        return (1);

    if (header.msg_type >=
        sizeof (ds_msg_handlers) / sizeof (ds_msg_handler_t))
        return (1);

    /*
     * handle data as a special case
     */
    if (header.msg_type == 9)
        return (poller_handle_data(lsp->fds_chan.fd,
            header.payload_len));

    /*
     * all other types of messages should be small
     */
    ASSERT(header.payload_len < 1024);
    msg_buf = alloca(header.payload_len);

    /*
     * read the payload
     */
    if (read_stream(lsp->fds_chan.fd, msg_buf, header.payload_len) != 0)
        return (1);

    (*ds_msg_handlers[header.msg_type])(lsp, msg_buf, header.payload_len);

    return (0);
}


/*
 * return values:
 *  0 - success
 *  1 - problem with opening the channel
 *  2 - channed not opened; request to exit has been detected
 */
static int
channel_openreset(struct ldmsvcs_info *lsp)
{
    int ier;

    ier = pthread_mutex_lock(&lsp->mt);

    if (ier == EINVAL || lsp->fds_chan.state == CHANNEL_EXIT ||
        lsp->fds_chan.state == CHANNEL_UNUSABLE) {
        (void) pthread_mutex_unlock(&lsp->mt);
        return (2);
    }

    if (lsp->fds_chan.state == CHANNEL_UNINITIALIZED ||
        lsp->fds_chan.state == CHANNEL_CLOSED) {
        (void) pthread_cond_broadcast(&lsp->cv);

        if ((lsp->fds_chan.fd = open(FDS_VLDC, O_RDWR)) < 0) {
            lsp->fds_chan.state = CHANNEL_UNUSABLE;
            lsp->cv_twait = get_smf_int_val(LDM_RUNNING_TO_PROP_NM,
                0, LDM_TIMEOUT_CEILING, LDM_RUNNING_WAIT_TIME);
            (void) pthread_mutex_unlock(&lsp->mt);
            (void) pthread_cond_broadcast(&lsp->fmas_svcs.cv);

            return (2);
        } else {
            vldc_opt_op_t op;

            op.op_sel = VLDC_OP_SET;
            op.opt_sel = VLDC_OPT_MODE;
            op.opt_val = LDC_MODE_RELIABLE;

            if (ioctl(lsp->fds_chan.fd, VLDC_IOCTL_OPT_OP,
                &op) != 0) {
                (void) close(lsp->fds_chan.fd);
                (void) pthread_mutex_unlock(&lsp->mt);
                return (1);
            }
        }
        lsp->fds_chan.state = CHANNEL_OPEN;
    }

    if (lsp->fds_chan.state == CHANNEL_OPEN) {
        /*
         * reset various channel parameters
         */
        lsp->fds_chan.ver.major = 0;
        lsp->fds_chan.ver.minor = 0;
        fds_svc_reset(lsp, -1);
    }
    (void) pthread_mutex_unlock(&lsp->mt);

    return (0);
}


static void
channel_fini(void)
{
    int i;
    struct ldmsvcs_info *lsp;

    /*
     * End the poller thread
     */
    poller_fini();

    if ((lsp = channel_init(NULL)) == NULL)
        return;

    (void) pthread_mutex_lock(&lsp->mt);

    lsp->fds_chan.state = CHANNEL_EXIT;
    (void) close(lsp->fds_chan.fd);

    (void) pthread_mutex_unlock(&lsp->mt);

    /* Free the ldom service structure */
    for (i = 0; i < lsp->fmas_svcs.nsvcs; i++) {
        ldom_free(lsp->fmas_svcs.tbl[i], sizeof (fds_svc_t));
    }
    ldom_free(lsp->fmas_svcs.tbl,
        lsp->fmas_svcs.nsvcs * sizeof (fds_svc_t *));
    ldom_free(lsp, sizeof (struct ldmsvcs_info));
}


static struct ldmsvcs_info *
channel_init(struct ldom_hdl *lhp)
{
    static pthread_mutex_t mt = PTHREAD_MUTEX_INITIALIZER;
    static pthread_cond_t cv = PTHREAD_COND_INITIALIZER;
    static struct ldmsvcs_info *root = NULL;
    static int busy_init = 0;

    struct timespec twait;
    int expired;

    (void) pthread_mutex_lock(&mt);

    while (busy_init == 1)
        (void) pthread_cond_wait(&cv, &mt);

    if (root != NULL || (lhp == NULL && root == NULL)) {
        (void) pthread_mutex_unlock(&mt);
        return (root);
    }

    /*
     * get to this point if we need to open the channel
     */
    busy_init = 1;
    (void) pthread_mutex_unlock(&mt);

    root = (struct ldmsvcs_info *)
        ldom_alloc(sizeof (struct ldmsvcs_info));
    bzero(root, sizeof (struct ldmsvcs_info));

    root->fds_chan.state = CHANNEL_UNINITIALIZED;
    root->cv_twait = get_smf_int_val(LDM_INIT_TO_PROP_NM,
        0, LDM_TIMEOUT_CEILING, LDM_INIT_WAIT_TIME);

    if (pthread_mutex_init(&root->mt, NULL) != 0 ||
        pthread_cond_init(&root->cv, NULL) != 0) {
        ldom_free(root, sizeof (struct ldmsvcs_info));
        return (NULL);
    }

    fds_svc_alloc(root);
    fds_svc_reset(root, -1);

    (void) poller_init(root);

    expired = 0;
    twait.tv_sec = time(NULL) + 10;
    twait.tv_nsec = 0;

    (void) pthread_mutex_lock(&root->mt);

    /*
     * wait for channel to become uninitialized.  this should be quick.
     */
    while (root->fds_chan.state == CHANNEL_UNINITIALIZED && expired == 0)
        expired = pthread_cond_timedwait(&root->cv, &root->mt, &twait);

    if (root->fds_chan.state == CHANNEL_UNUSABLE)
        expired = 1;

    (void) pthread_mutex_unlock(&root->mt);

    (void) pthread_mutex_lock(&mt);
    busy_init = 0;
    (void) pthread_mutex_unlock(&mt);
    (void) pthread_cond_broadcast(&cv);

    (void) atexit(channel_fini);

    if (expired == 0)
        return (root);
    else
        return (NULL);
}


static int
sendrecv(struct ldom_hdl *lhp, uint64_t req_num,
    void *msg, size_t msglen, ds_svc_hdl_t *svc_hdl, char *svcname,
    void **resp, size_t *resplen)
{
    struct ldmsvcs_info *lsp;
    fds_svc_t *svc;
    int maxretries, index, i, ier;

    lsp = lhp->lsinfo;
    i = 0;
    maxretries = 1;

    do {
        /*
         * if any of the calls in this loop fail, retry some number
         * of times before giving up.
         */
        if ((svc = fds_svc_lookup(lsp, svcname)) == NULL) {
            (void) pthread_mutex_lock(&lsp->mt);

            if (lsp->fds_chan.state != CHANNEL_READY)
                ier = ETIMEDOUT;    /* channel not ready */
            else
                ier = ENOTSUP;      /* service not ready */

            (void) pthread_mutex_unlock(&lsp->mt);

            continue;
        } else {
            ier = 0;
            *svc_hdl = svc->hdl;
        }

        index = poller_add_pending(req_num);

        if ((ier = fds_send(lsp, msg, msglen)) != 0 ||
            (ier = poller_recv_data(lhp, req_num, index, resp,
            resplen)) != 0)
            poller_delete_pending(req_num, index);

    } while (i++ < maxretries && ier != 0);

    ASSERT(ier == 0 || ier == ETIMEDOUT || ier == ENOTSUP);

    return (ier);
}


/*
 * input:
 *   msg_type - requested operation: FMA_CPU_REQ_STATUS or FMA_CPU_REQ_OFFLINE
 *   cpuid - physical cpu id
 *
 * normal return values:
 *   P_OFFLINE - cpu is offline
 *   P_ONLINE - cpu is online
 *
 * abnormal return values:
 *   ETIMEDOUT - LDOM manager is not responding
 *   ENOTSUP - LDOM service for cpu offlining/status is not available
 *   ENOMSG - got an unexpected response from the LDOM cpu service
 */
static int
cpu_request(struct ldom_hdl *lhp, uint32_t msg_type, uint32_t cpuid)
{
    ds_hdr_t *H;
    ds_data_handle_t *D;
    fma_cpu_service_req_t *R;

    char *svcname = LDM_DS_NAME_CPU;
    fma_cpu_resp_t *respmsg;
    void *resp;
    size_t resplen, reqmsglen;
    int rc;

    if (lhp->lsinfo == NULL)
        return (ENOMSG);

    reqmsglen = sizeof (ds_hdr_t) + sizeof (ds_data_handle_t) +
        sizeof (fma_cpu_service_req_t);

    H = lhp->allocp(reqmsglen);
    D = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));
    R = (void *)((ptrdiff_t)D + sizeof (ds_data_handle_t));

    H->msg_type = DS_DATA;
    H->payload_len = sizeof (ds_data_handle_t) +
        sizeof (fma_cpu_service_req_t);

    R->req_num = fds_svc_req_num();
    R->msg_type = msg_type;
    R->cpu_id = cpuid;

    if ((rc = sendrecv(lhp, R->req_num, H, reqmsglen,
        &D->svc_handle, svcname, &resp, &resplen)) != 0) {
        lhp->freep(H, reqmsglen);
        return (rc);
    }

    lhp->freep(H, reqmsglen);

    ASSERT(resplen == sizeof (fma_cpu_resp_t));
    respmsg = (fma_cpu_resp_t *)resp;

    rc = ENOMSG;
    if (respmsg->result == FMA_CPU_RESP_OK) {
        if (respmsg->status == FMA_CPU_STAT_ONLINE)
            rc = P_ONLINE;
        else if (respmsg->status == FMA_CPU_STAT_OFFLINE)
            rc = P_OFFLINE;
    } else {
        if (msg_type == FMA_CPU_REQ_OFFLINE &&
            respmsg->status == FMA_CPU_STAT_OFFLINE)
            rc = P_OFFLINE;
    }

    lhp->freep(resp, resplen);

    return (rc);
}


/*
 * input:
 *   msg_type - requested operation: FMA_MEM_REQ_STATUS or FMA_MEM_REQ_RETIRE
 *   pa - starting address of memory page
 *   pgsize - memory page size in bytes
 *
 * normal return values for msg_type == FMA_MEM_REQ_STATUS:
 *   0 - page is retired
 *   EAGAIN - page is scheduled for retirement
 *   EIO - page not scheduled for retirement
 *   EINVAL - error
 *
 * normal return values for msg_type == FMA_MEM_REQ_RETIRE:
 *   0 - success in retiring page
 *   EIO - page is already retired
 *   EAGAIN - page is scheduled for retirement
 *   EINVAL - error
 *
 * abnormal return values (regardless of msg_type)
 *   ETIMEDOUT - LDOM manager is not responding
 *   ENOTSUP - LDOM service for cpu offlining/status is not available
 *   ENOMSG - got an unexpected response from the LDOM cpu service
 */
static int
mem_request(struct ldom_hdl *lhp, uint32_t msg_type, uint64_t pa,
        uint64_t pgsize)
{
    ds_hdr_t *H;
    ds_data_handle_t *D;
    fma_mem_service_req_t *R;

    char *svcname = LDM_DS_NAME_MEM;
    fma_mem_resp_t *respmsg;
    void *resp;
    size_t resplen, reqmsglen;
    int rc;

    if (lhp->lsinfo == NULL)
        return (ENOMSG);

    reqmsglen = sizeof (ds_hdr_t) + sizeof (ds_data_handle_t) +
        sizeof (fma_mem_service_req_t);

    H = lhp->allocp(reqmsglen);
    bzero(H, reqmsglen);
    D = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));
    R = (void *)((ptrdiff_t)D + sizeof (ds_data_handle_t));

    H->msg_type = DS_DATA;
    H->payload_len = sizeof (ds_data_handle_t) +
        sizeof (fma_mem_service_req_t);

    R->req_num = fds_svc_req_num();
    R->msg_type = msg_type;
    R->real_addr = pa;
    R->length = pgsize;

    if ((rc = sendrecv(lhp, R->req_num, H, reqmsglen,
        &D->svc_handle, svcname, &resp, &resplen)) != 0) {
        lhp->freep(H, reqmsglen);
        return (rc);
    }

    lhp->freep(H, reqmsglen);

    ASSERT(resplen == sizeof (fma_mem_resp_t));
    respmsg = (fma_mem_resp_t *)resp;

    rc = ENOMSG;
    if (msg_type == FMA_MEM_REQ_STATUS) {
        if (respmsg->result == FMA_MEM_RESP_OK) {
            if (respmsg->status == FMA_MEM_STAT_RETIRED)
                rc = 0;     /* page is retired */
            else if (respmsg->status == FMA_MEM_STAT_NOTRETIRED)
                rc = EIO;   /* page is not scheduled */
        } else if (respmsg->result == FMA_MEM_RESP_FAILURE) {
            if (respmsg->status == FMA_MEM_STAT_NOTRETIRED)
                rc = EAGAIN;    /* page is scheduled */
            else if (respmsg->status == FMA_MEM_STAT_ILLEGAL)
                rc = EINVAL;
        }
    } else if (msg_type == FMA_MEM_REQ_RETIRE) {
        if (respmsg->result == FMA_MEM_RESP_OK) {
            if (respmsg->status == FMA_MEM_STAT_RETIRED)
                rc = 0;     /* is successfully retired */
        } else if (respmsg->result == FMA_MEM_RESP_FAILURE) {
            if (respmsg->status == FMA_MEM_STAT_RETIRED)
                rc = EIO;   /* is already retired */
            else if (respmsg->status == FMA_MEM_STAT_NOTRETIRED)
                rc = EAGAIN;    /* is scheduled to retire */
            else if (respmsg->status == FMA_MEM_STAT_ILLEGAL)
                rc = EINVAL;
        }
    } else if (msg_type == FMA_MEM_REQ_RESURRECT) {
        if (respmsg->result == FMA_MEM_RESP_OK) {
            if (respmsg->status == FMA_MEM_STAT_NOTRETIRED)
                rc = 0;     /* is successfully unretired */
        } if (respmsg->result == FMA_MEM_RESP_FAILURE) {
            if (respmsg->status == FMA_MEM_STAT_RETIRED)
                rc = EAGAIN;    /* page couldn't be locked */
            else if (respmsg->status == FMA_MEM_STAT_NOTRETIRED)
                rc = EIO;   /* page isn't retired already */
            else if (respmsg->status == FMA_MEM_STAT_ILLEGAL)
                rc = EINVAL;
        }
    }

    lhp->freep(resp, resplen);

    return (rc);
}


/*
 * APIs
 */
int
ldmsvcs_check_channel(void)
{
    struct stat buf;

    if (stat(FDS_VLDC, &buf) == 0)
        return (0); /* vldc exists */
    else if (errno == ENOENT || errno == ENOTDIR)
        return (1); /* vldc does not exist */
    else
        return (-1);    /* miscellaneous error */
}


/*ARGSUSED*/
void
ldmsvcs_init(struct ldom_hdl *lhp)
{
    if (ldmsvcs_check_channel() != 0)
        return;

    lhp->lsinfo = channel_init(lhp);
    poller_add_client();
}


/*ARGSUSED*/
void
ldmsvcs_fini(struct ldom_hdl *lhp)
{
    if (ldmsvcs_check_channel() != 0)
        return;

    poller_remove_client();
}


/*ARGSUSED*/
ssize_t
ldmsvcs_get_core_md(struct ldom_hdl *lhp, uint64_t **buf)
{
    ds_hdr_t *H;
    ds_data_handle_t *D;
    fma_req_pri_t *R;

    char *svcname = LDM_DS_NAME_PRI;
    void *resp;
    size_t resplen, reqmsglen;
    ssize_t buflen;
    int rc;

    if (lhp->lsinfo == NULL)
        return (-1);

    reqmsglen = sizeof (ds_hdr_t) + sizeof (ds_data_handle_t) +
        sizeof (fma_req_pri_t);

    H = lhp->allocp(reqmsglen);
    D = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));
    R = (void *)((ptrdiff_t)D + sizeof (ds_data_handle_t));

    H->msg_type = DS_DATA;
    H->payload_len = sizeof (ds_data_handle_t) +
        sizeof (fma_req_pri_t);

    R->req_num = fds_svc_req_num();

    if ((rc = sendrecv(lhp, R->req_num, H, reqmsglen,
        &D->svc_handle, svcname, &resp, &resplen)) != 0) {
        lhp->freep(H, reqmsglen);
        errno = rc;
        return (-1);
    }

    lhp->freep(H, reqmsglen);

    /*
     * resp should contain the req_num immediately followed by the PRI
     * (the latter may or may not be present).  unfortunately, the
     * current compiler flags cause a warning for the following
     * definition
     *
     * typedef struct {
     *    uint64_t req_num;
     *    uint8_t pri[];
     *  } fma_pri_resp_t;
     *
     * so we do not use the struct here.
     */
    if (resplen <= sizeof (uint64_t)) {
        lhp->freep(resp, resplen);
        if (resplen == sizeof (uint64_t))
            return (0);
        else
            return (-1);
    }

    buflen = resplen - sizeof (uint64_t);
    *buf = lhp->allocp(buflen);

    bcopy((void *)((ptrdiff_t)resp + sizeof (uint64_t)), *buf, buflen);
    lhp->freep(resp, resplen);

    return (buflen);
}


/*
 * see cpu_request() for a description of return values
 */
int
ldmsvcs_cpu_req_status(struct ldom_hdl *lhp, uint32_t cpuid)
{
    return (cpu_request(lhp, FMA_CPU_REQ_STATUS, cpuid));
}


int
ldmsvcs_cpu_req_offline(struct ldom_hdl *lhp, uint32_t cpuid)
{
    return (cpu_request(lhp, FMA_CPU_REQ_OFFLINE, cpuid));
}

int
ldmsvcs_cpu_req_online(struct ldom_hdl *lhp, uint32_t cpuid)
{
    return (cpu_request(lhp, FMA_CPU_REQ_ONLINE, cpuid));
}

/*
 * see mem_request() for a description of return values
 */
int
ldmsvcs_mem_req_status(struct ldom_hdl *lhp, uint64_t pa)
{
    return (mem_request(lhp, FMA_MEM_REQ_STATUS, pa, getpagesize()));
}

int
ldmsvcs_mem_req_retire(struct ldom_hdl *lhp, uint64_t pa)
{
    return (mem_request(lhp, FMA_MEM_REQ_RETIRE, pa, getpagesize()));
}

int
ldmsvcs_mem_req_unretire(struct ldom_hdl *lhp, uint64_t pa)
{
    return (mem_request(lhp, FMA_MEM_REQ_RESURRECT, pa, getpagesize()));
}

int
ldmsvcs_io_req_id(struct ldom_hdl *lhp, uint64_t addr, uint_t type,
    uint64_t *virt_addr, char *name, int name_len, uint64_t *did)
{

    ds_hdr_t *H;
    ds_data_handle_t *D;
    fma_io_req_t *R;

    char *svcname = LDM_DS_NAME_IOD;
    void *resp;
    fma_io_resp_t *iop;
    size_t resplen, reqmsglen;
    int offset;
    int rc;

    if (lhp->lsinfo == NULL)
        return (-1);

    reqmsglen = sizeof (ds_hdr_t) + sizeof (ds_data_handle_t) +
        sizeof (fma_io_req_t);

    H = lhp->allocp(reqmsglen);
    D = (void *)((ptrdiff_t)H + sizeof (ds_hdr_t));
    R = (void *)((ptrdiff_t)D + sizeof (ds_data_handle_t));

    H->msg_type = DS_DATA;
    H->payload_len = sizeof (ds_data_handle_t) + sizeof (fma_io_req_t);

    R->req_num = fds_svc_req_num();
    R->msg_type = type;
    R->rsrc_address = addr;

    rc = ENOMSG;
    if ((rc = sendrecv(lhp, R->req_num, H, reqmsglen,
        &D->svc_handle, svcname, &resp, &resplen)) != 0) {
        lhp->freep(H, reqmsglen);
        return (rc);
    }
    lhp->freep(H, reqmsglen);

    /*
     * resp should contain the req_num, status, virtual addr, domain id
     * and the domain name. The domain name may or may not be present.
     */
    offset = sizeof (fma_io_resp_t);
    if (resplen < offset) {
        lhp->freep(resp, resplen);
        return (-1);
    }

    iop = (fma_io_resp_t *)resp;
    switch (iop->result) {
    case FMA_IO_RESP_OK:
        /* success */
        rc = 0;
        *virt_addr = iop->virt_rsrc_address;
        *did = iop->domain_id;
        if (name == NULL || name_len <= 0)
            break;
        *name = '\0';
        if (resplen > offset) {
            (void) strncpy(name, (char *)((ptrdiff_t)resp + offset),
                name_len);
        }
        break;
    default:
        rc = -1;
        break;
    }

    lhp->freep(resp, resplen);
    return (rc);
}

/* end file */