libtopo/common/dev.c

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

/*
 * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <limits.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <alloca.h>
#include <devid.h>
#include <sys/stat.h>
#include <libnvpair.h>
#include <fm/topo_mod.h>
#include <fm/fmd_fmri.h>
#include <sys/fm/protocol.h>

#include <topo_method.h>
#include <topo_subr.h>
#include <dev.h>

static int dev_enum(topo_mod_t *, tnode_t *, const char *, topo_instance_t,
    topo_instance_t, void *, void *);
static void dev_release(topo_mod_t *, tnode_t *);
static int dev_fmri_nvl2str(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int dev_fmri_str2nvl(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int dev_fmri_create_meth(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int dev_fmri_present(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int dev_fmri_replaced(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int dev_fmri_unusable(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int dev_fmri_service_state(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);

static const topo_method_t dev_methods[] = {
    { TOPO_METH_NVL2STR, TOPO_METH_NVL2STR_DESC, TOPO_METH_NVL2STR_VERSION,
        TOPO_STABILITY_INTERNAL, dev_fmri_nvl2str },
    { TOPO_METH_STR2NVL, TOPO_METH_STR2NVL_DESC, TOPO_METH_STR2NVL_VERSION,
        TOPO_STABILITY_INTERNAL, dev_fmri_str2nvl },
    { TOPO_METH_FMRI, TOPO_METH_FMRI_DESC, TOPO_METH_FMRI_VERSION,
        TOPO_STABILITY_INTERNAL, dev_fmri_create_meth },
    { TOPO_METH_PRESENT, TOPO_METH_PRESENT_DESC, TOPO_METH_PRESENT_VERSION,
        TOPO_STABILITY_INTERNAL, dev_fmri_present },
    { TOPO_METH_REPLACED, TOPO_METH_REPLACED_DESC,
        TOPO_METH_REPLACED_VERSION, TOPO_STABILITY_INTERNAL,
        dev_fmri_replaced },
    { TOPO_METH_UNUSABLE, TOPO_METH_UNUSABLE_DESC,
        TOPO_METH_UNUSABLE_VERSION, TOPO_STABILITY_INTERNAL,
        dev_fmri_unusable },
    { TOPO_METH_SERVICE_STATE, TOPO_METH_SERVICE_STATE_DESC,
        TOPO_METH_SERVICE_STATE_VERSION, TOPO_STABILITY_INTERNAL,
        dev_fmri_service_state },
    { NULL }
};

static const topo_modops_t dev_ops =
    { dev_enum, dev_release };
static const topo_modinfo_t dev_info =
    { "dev", FM_FMRI_SCHEME_DEV, DEV_VERSION, &dev_ops };

int
dev_init(topo_mod_t *mod, topo_version_t version)
{
    if (getenv("TOPOHCDEBUG"))
        topo_mod_setdebug(mod);
    topo_mod_dprintf(mod, "initializing dev builtin\n");

    if (version != DEV_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (topo_mod_register(mod, &dev_info, TOPO_VERSION) != 0) {
        topo_mod_dprintf(mod, "failed to register dev_info: "
            "%s\n", topo_mod_errmsg(mod));
        return (-1);
    }

    return (0);
}

void
dev_fini(topo_mod_t *mod)
{
    topo_mod_unregister(mod);
}

/*ARGSUSED*/
static int
dev_enum(topo_mod_t *mod, tnode_t *pnode, const char *name,
    topo_instance_t min, topo_instance_t max, void *notused1, void *notused2)
{
    /*
     * Methods are registered, but there is no enumeration.  Should
     * enumeration be added be sure to cater for global vs non-global
     * zones.
     */
    (void) topo_method_register(mod, pnode, dev_methods);
    return (0);
}

static void
dev_release(topo_mod_t *mod, tnode_t *node)
{
    topo_method_unregister_all(mod, node);
}

static ssize_t
fmri_nvl2str(nvlist_t *nvl, char *buf, size_t buflen)
{
    char *devid = NULL, *tpl0id = NULL;
    char *devpath = NULL;
    ssize_t size = 0;
    uint8_t version;
    int err;

    if (nvlist_lookup_uint8(nvl, FM_VERSION, &version) != 0 ||
        version > FM_DEV_SCHEME_VERSION)
        return (-1);

    /* Get devid, if present */
    err = nvlist_lookup_string(nvl, FM_FMRI_DEV_ID, &devid);
    if (err != 0 && err != ENOENT)
        return (-1);

    /* Get target-port-l0id, if present */
    err = nvlist_lookup_string(nvl, FM_FMRI_DEV_TGTPTLUN0, &tpl0id);
    if (err != 0 && err != ENOENT)
        return (-1);

    /* There must be a device path present */
    err = nvlist_lookup_string(nvl, FM_FMRI_DEV_PATH, &devpath);
    if (err != 0 || devpath == NULL)
        return (-1);

    /*
     * dev:///
     *
     * The dev scheme does not render fmri authority information
     * in the string form of an fmri.  It is meaningless to
     * transmit a dev scheme fmri outside of the immediate fault
     * manager.
     */
    topo_fmristr_build(&size,
        buf, buflen, FM_FMRI_SCHEME_DEV, NULL, ":///");

    /* device-id part, topo_fmristr_build does nothing if devid is NULL */
    topo_fmristr_build(&size,
        buf, buflen, devid, ":" FM_FMRI_DEV_ID "=", NULL);

    /* target-port-l0id part */
    topo_fmristr_build(&size,
        buf, buflen, tpl0id, ":" FM_FMRI_DEV_TGTPTLUN0 "=", NULL);

    /*
     * device-path part; the devpath should always start with a /
     * so you'd think we don't need to add a further / prefix here;
     * however past implementation has always added the / if
     * there is a devid component so we continue to do that
     * so strings match exactly as before.  So we can have:
     *
     *  dev:////pci@0,0/...
     *  dev:///<devid-and-tpl0>//pci@0,0/...
     *
     *  where <devid-and-tpl0> =
     *          [:devid=<devid>][:target-port-l0id=<tpl0>]
     */
    topo_fmristr_build(&size, buf, buflen, devpath,
        devid || tpl0id ? "/" : NULL, NULL);

    return (size);
}

/*ARGSUSED*/
static int
dev_fmri_nvl2str(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *nvl, nvlist_t **out)
{
    ssize_t len;
    char *name = NULL;
    nvlist_t *fmristr;

    if (version > TOPO_METH_NVL2STR_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if ((len = fmri_nvl2str(nvl, NULL, 0)) == 0 ||
        (name = topo_mod_alloc(mod, len + 1)) == NULL ||
        fmri_nvl2str(nvl, name, len + 1) == 0) {
        if (name != NULL)
            topo_mod_free(mod, name, len + 1);
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }

    if (topo_mod_nvalloc(mod, &fmristr, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    if (nvlist_add_string(fmristr, "fmri-string", name) != 0) {
        topo_mod_free(mod, name, len + 1);
        nvlist_free(fmristr);
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }
    topo_mod_free(mod, name, len + 1);
    *out = fmristr;

    return (0);
}

/*ARGSUSED*/
static int
dev_fmri_str2nvl(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    char *cur, *devid = NULL, *tpl0id = NULL;
    char *str, *strcp;
    nvlist_t *fmri;
    char *devpath;
    size_t len;
    int err;

    if (version > TOPO_METH_STR2NVL_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_string(in, "fmri-string", &str) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));

    len = strlen(str);

    /*
     * We're expecting a string version of a dev scheme FMRI, and
     * no fmri authority information.
     *
     * The shortest legal string would be "dev:////" (len 8) for a string
     * with no FMRI auth info, no devid or target-port-l0id and
     * an empty devpath string.
     */
    if (len < 8 || strncmp(str, "dev:///", 7) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    strcp = alloca(len + 1);
    (void) memcpy(strcp, str, len);
    strcp[len] = '\0';
    cur = strcp + 7;    /* already parsed "dev:///" */

    /*
     * If the first character after the "/" that terminates the (empty)
     * fmri authority is a colon then we have devid and/or target-port-l0id
     * info.  They could be in either order.
     *
     * If not a colon then it must be the / that begins the devpath.
     */
    if (*cur == ':') {
        char *eos, *part[2];
        int i;
        /*
         * Look ahead to the "/" that starts the devpath.  If not
         * found or if straight after the : then we're busted.
         */
        eos = devpath = strchr(cur, '/');
        if (devpath == NULL || devpath == cur + 1)
            return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

        part[0] = ++cur;

        /*
         * Replace the initial "/" of the devpath with a NUL
         * to terminate the string before it.  We'll undo this
         * before rendering devpath.
         */
        *eos = '\0';

        /*
         * We should now have a NUL-terminated string matching
         * foo=<pat1>[:bar=<pat2>] (we stepped over the initial :)
         * Look for a second colon; if found there must be space
         * after it for the additional component, but no more colons.
         */
        if ((part[1] = strchr(cur, ':')) != NULL) {
            if (part[1] + 1 == eos ||
                strchr(part[1] + 1, ':') != NULL)
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            *part[1] = '\0'; /* terminate part[0] */
            part[1]++;
        }

        for (i = 0; i < 2; i++) {
            char *eq;

            if (!part[i])
                continue;

            if ((eq = strchr(part[i], '=')) == NULL ||
                *(eq + 1) == '\0')
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));

            *eq = '\0';
            if (strcmp(part[i], FM_FMRI_DEV_ID) == 0)
                devid = eq + 1;
            else if (strcmp(part[i], FM_FMRI_DEV_TGTPTLUN0) == 0)
                tpl0id = eq + 1;
            else
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
        }

        if (devid == NULL && tpl0id == NULL)
            return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

        cur = devpath;  /* initial slash is NULled */
    } else if (*cur != '/') {
        /* the device-path should start with a slash */
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));
    } else {
        devpath = cur;
    }

    if (topo_mod_nvalloc(mod, &fmri, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));

    err = nvlist_add_uint8(fmri, FM_VERSION, FM_DEV_SCHEME_VERSION);
    err |= nvlist_add_string(fmri, FM_FMRI_SCHEME, FM_FMRI_SCHEME_DEV);

    if (devid != NULL)
        err |= nvlist_add_string(fmri, FM_FMRI_DEV_ID, devid);

    if (tpl0id != NULL)
        err |= nvlist_add_string(fmri, FM_FMRI_DEV_TGTPTLUN0, tpl0id);

    if (devid != NULL || tpl0id != NULL)
        *devpath = '/'; /* we NULed this earlier; put it back */

    /* step over repeated initial / in the devpath */
    while (*(devpath + 1) == '/')
        devpath++;

    err |= nvlist_add_string(fmri, FM_FMRI_DEV_PATH, devpath);

    if (err != 0) {
        nvlist_free(fmri);
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }

    *out = fmri;

    return (0);
}

/*ARGSUSED*/
static int
dev_fmri_present(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    uint8_t fmversion;
    char *devpath = NULL;
    uint32_t present;
    char *devid = NULL, *path;
    ddi_devid_t id;
    ddi_devid_t matchid;
    di_node_t dnode;
    struct stat sb;
    int len;

    if (version > TOPO_METH_PRESENT_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_uint8(in, FM_VERSION, &fmversion) != 0 ||
        fmversion > FM_DEV_SCHEME_VERSION ||
        nvlist_lookup_string(in, FM_FMRI_DEV_PATH, &devpath) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    (void) nvlist_lookup_string(in, FM_FMRI_DEV_ID, &devid);

    if (devpath == NULL || strlen(devpath) == 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    /*
     * stat() the device node in devfs. This will tell us if the device is
     * present or not. Don't stat the minor,  just the whole device.
     * If the device is present and there is a devid, it must also match.
     * so di_init that one node. No need for DINFOFORCE.
     */
    len = strlen(devpath) + strlen("/devices") + 1;
    path = topo_mod_alloc(mod, len);
    (void) snprintf(path, len, "/devices%s", devpath);
    if (devid == NULL) {
        if (stat(path, &sb) != -1)
            present = 1;
        else if ((dnode = di_init("/", DINFOCACHE)) == DI_NODE_NIL)
            present = 0;
        else {
            if (di_lookup_node(dnode, devpath) == DI_NODE_NIL)
                present = 0;
            else
                present = 1;
            di_fini(dnode);
        }
    } else {
        if (stat(path, &sb) == -1)
            present = 0;
        else if ((dnode = di_init(devpath, DINFOCPYONE)) == DI_NODE_NIL)
            present = 0;
        else {
            if ((id = di_devid(dnode)) == NULL ||
                devid_str_decode(devid, &matchid, NULL) != 0)
                present = 0;
            else {
                if (devid_compare(id, matchid) != 0)
                    present = 0;
                else
                    present = 1;
                devid_free(matchid);
            }
            di_fini(dnode);
        }
    }
    topo_mod_free(mod, path, len);

    if (topo_mod_nvalloc(mod, out, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    if (nvlist_add_uint32(*out, TOPO_METH_PRESENT_RET, present) != 0) {
        nvlist_free(*out);
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    }

    return (0);
}

/*ARGSUSED*/
static int
dev_fmri_replaced(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    uint8_t fmversion;
    char *devpath = NULL;
    uint32_t rval;
    char *devid = NULL, *path;
    ddi_devid_t id;
    ddi_devid_t matchid;
    di_node_t dnode;
    struct stat sb;
    int len;

    if (version > TOPO_METH_REPLACED_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_uint8(in, FM_VERSION, &fmversion) != 0 ||
        fmversion > FM_DEV_SCHEME_VERSION ||
        nvlist_lookup_string(in, FM_FMRI_DEV_PATH, &devpath) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    (void) nvlist_lookup_string(in, FM_FMRI_DEV_ID, &devid);

    if (devpath == NULL || strlen(devpath) == 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    /*
     * stat() the device node in devfs. This will tell us if the device is
     * present or not. Don't stat the minor,  just the whole device.
     * If the device is present and there is a devid, it must also match.
     * so di_init that one node. No need for DINFOFORCE.
     */
    len = strlen(devpath) + strlen("/devices") + 1;
    path = topo_mod_alloc(mod, len);
    (void) snprintf(path, len, "/devices%s", devpath);
    if (devid == NULL) {
        if (stat(path, &sb) != -1)
            rval = FMD_OBJ_STATE_UNKNOWN;
        else if ((dnode = di_init("/", DINFOCACHE)) == DI_NODE_NIL)
            rval = FMD_OBJ_STATE_UNKNOWN;
        else {
            if (di_lookup_node(dnode, devpath) == DI_NODE_NIL)
                rval = FMD_OBJ_STATE_UNKNOWN;
            else
                rval = FMD_OBJ_STATE_UNKNOWN;
            di_fini(dnode);
        }
    } else {
        if (stat(path, &sb) == -1)
            rval = FMD_OBJ_STATE_UNKNOWN;
        else if ((dnode = di_init(devpath, DINFOCPYONE)) == DI_NODE_NIL)
            rval = FMD_OBJ_STATE_UNKNOWN;
        else {
            if ((id = di_devid(dnode)) == NULL ||
                devid_str_decode(devid, &matchid, NULL) != 0)
                rval = FMD_OBJ_STATE_UNKNOWN;
            else {
                if (devid_compare(id, matchid) != 0)
                    rval = FMD_OBJ_STATE_REPLACED;
                else
                    rval = FMD_OBJ_STATE_STILL_PRESENT;
                devid_free(matchid);
            }
            di_fini(dnode);
        }
    }
    topo_mod_free(mod, path, len);

    if (topo_mod_nvalloc(mod, out, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    if (nvlist_add_uint32(*out, TOPO_METH_REPLACED_RET, rval) != 0) {
        nvlist_free(*out);
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    }

    return (0);
}

/*ARGSUSED*/
static int
dev_fmri_unusable(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    di_node_t dnode;
    uint8_t fmversion;
    char *devpath = NULL;
    uint32_t unusable;
    uint_t state;

    if (version > TOPO_METH_UNUSABLE_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_uint8(in, FM_VERSION, &fmversion) != 0 ||
        fmversion > FM_DEV_SCHEME_VERSION ||
        nvlist_lookup_string(in, FM_FMRI_DEV_PATH, &devpath) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    if (devpath == NULL)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    if ((dnode = di_init(devpath, DINFOCPYONE)) == DI_NODE_NIL) {
        if (errno != ENXIO)
            return (topo_mod_seterrno(mod, EMOD_UKNOWN_ENUM));
        unusable = 1;
    } else {
        uint_t retired = di_retired(dnode);
        state = di_state(dnode);
        if (retired || (state & (DI_DEVICE_OFFLINE | DI_DEVICE_DOWN |
            DI_BUS_QUIESCED | DI_BUS_DOWN)))
            unusable = 1;
        else
            unusable = 0;
        di_fini(dnode);
    }

    if (topo_mod_nvalloc(mod, out, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    if (nvlist_add_uint32(*out, TOPO_METH_UNUSABLE_RET, unusable) != 0) {
        nvlist_free(*out);
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    }

    return (0);
}

/*ARGSUSED*/
static int
dev_fmri_service_state(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    di_node_t dnode;
    uint8_t fmversion;
    char *devpath = NULL;
    uint32_t service_state;
    uint_t state;

    if (version > TOPO_METH_SERVICE_STATE_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_uint8(in, FM_VERSION, &fmversion) != 0 ||
        fmversion > FM_DEV_SCHEME_VERSION ||
        nvlist_lookup_string(in, FM_FMRI_DEV_PATH, &devpath) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    if (devpath == NULL)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    if ((dnode = di_init(devpath, DINFOCPYONE)) == DI_NODE_NIL) {
        if (errno != ENXIO)
            return (topo_mod_seterrno(mod, EMOD_UKNOWN_ENUM));
        service_state = FMD_SERVICE_STATE_UNUSABLE;
    } else {
        uint_t retired = di_retired(dnode);
        state = di_state(dnode);
        if (retired || (state & (DI_DEVICE_OFFLINE | DI_DEVICE_DOWN |
            DI_BUS_QUIESCED | DI_BUS_DOWN)))
            service_state = FMD_SERVICE_STATE_UNUSABLE;
        else if (state & DI_DEVICE_DEGRADED)
            service_state = FMD_SERVICE_STATE_DEGRADED;
        else
            service_state = FMD_SERVICE_STATE_OK;
        di_fini(dnode);
    }

    if (topo_mod_nvalloc(mod, out, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    if (nvlist_add_uint32(*out, TOPO_METH_SERVICE_STATE_RET,
        service_state) != 0) {
        nvlist_free(*out);
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    }

    return (0);
}

static nvlist_t *
dev_fmri_create(topo_mod_t *mp, const char *id, const char *path)
{
    nvlist_t *out = NULL;
    int e;

    if (topo_mod_nvalloc(mp, &out, NV_UNIQUE_NAME) != 0) {
        (void) topo_mod_seterrno(mp, EMOD_FMRI_NVL);
        return (NULL);
    }
    e = nvlist_add_string(out, FM_FMRI_SCHEME, FM_FMRI_SCHEME_DEV);
    e |= nvlist_add_uint8(out, FM_VERSION, FM_DEV_SCHEME_VERSION);
    e |= nvlist_add_string(out, FM_FMRI_DEV_PATH, path);

    if (id != NULL)
        e |= nvlist_add_string(out, FM_FMRI_DEV_ID, id);

    if (e == 0)
        return (out);

    topo_mod_dprintf(mp, "construction of dev nvl failed");
    (void) topo_mod_seterrno(mp, EMOD_FMRI_NVL);
    nvlist_free(out);
    return (NULL);
}

/*ARGSUSED*/
static int
dev_fmri_create_meth(topo_mod_t *mp, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    nvlist_t *args = NULL;
    char *path, *id = NULL;

    if (version > TOPO_METH_FMRI_VERSION)
        return (topo_mod_seterrno(mp, EMOD_VER_NEW));

    if (nvlist_lookup_nvlist(in, TOPO_METH_FMRI_ARG_NVL, &args) != 0 ||
        nvlist_lookup_string(args, FM_FMRI_DEV_PATH, &path) != 0) {
        topo_mod_dprintf(mp, "no path string in method argument\n");
        return (topo_mod_seterrno(mp, EMOD_METHOD_INVAL));
    }

    (void) nvlist_lookup_string(args, FM_FMRI_DEV_ID, &id);

    if ((*out = dev_fmri_create(mp, id, path)) == NULL)
        return (-1);
    return (0);
}