libdladm/common/libdladm.c

	libdladm.c revision 4eaa471005973e11a6110b69fe990530b3b95a38
/*
 * 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 <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <fcntl.h>
#include <strings.h>
#include <dirent.h>
#include <stdlib.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/dld.h>
#include <sys/dld_ioc.h>
#include <libdladm_impl.h>
#include <libintl.h>
#include <libdlpi.h>

static char dladm_rootdir[MAXPATHLEN] = "/";

typedef struct media_type_desc {
    uint32_t    media_type;
#define MAX_MEDIA_TYPE_STRING   32
    const char  media_type_str[MAX_MEDIA_TYPE_STRING];
} media_type_t;

static media_type_t media_type_table[] =  {
    { DL_ETHER, "Ethernet" },
    { DL_WIFI,  "WiFi" },
    { DL_IB,    "Infiniband" },
    { DL_IPV4,  "IPv4Tunnel" },
    { DL_IPV6,  "IPv6Tunnel" },
    { DL_CSMACD,    "CSMA/CD" },
    { DL_TPB,   "TokenBus" },
    { DL_TPR,   "TokenRing" },
    { DL_METRO, "MetroNet" },
    { DL_HDLC,  "HDLC" },
    { DL_CHAR,  "SyncCharacter" },
    { DL_CTCA,  "CTCA" },
    { DL_FDDI,  "FDDI" },
    { DL_FC,    "FiberChannel" },
    { DL_ATM,   "ATM" },
    { DL_IPATM,     "ATM(ClassicIP)" },
    { DL_X25,   "X.25" },
    { DL_IPX25,     "X.25(ClassicIP)" },
    { DL_ISDN,  "ISDN" },
    { DL_HIPPI,     "HIPPI" },
    { DL_100VG,     "100BaseVGEthernet" },
    { DL_100VGTPR,  "100BaseVGTokenRing" },
    { DL_ETH_CSMA,  "IEEE802.3" },
    { DL_100BT,     "100BaseT" },
    { DL_FRAME,     "FrameRelay" },
    { DL_MPFRAME,   "MPFrameRelay" },
    { DL_ASYNC,     "AsyncCharacter" },
    { DL_IPNET,     "IPNET" },
    { DL_OTHER,     "Other" }
};
#define MEDIATYPECOUNT  (sizeof (media_type_table) / sizeof (media_type_t))

dladm_status_t
dladm_open(dladm_handle_t *handle)
{
    int dld_fd;

    if (handle == NULL)
        return (DLADM_STATUS_BADARG);

    if ((dld_fd = open(DLD_CONTROL_DEV, O_RDWR)) < 0)
        return (dladm_errno2status(errno));

    /*
     * Don't open DLMGMT_DOOR now.  dlmgmtd(1M) is not able to
     * open the door when the dladm handle is opened because the
     * door hasn't been created yet at that time.  Thus, we must
     * open it on-demand in dladm_door_fd().  Move the open()
     * to dladm_door_fd() for all cases.
     */

    if ((*handle = malloc(sizeof (struct dladm_handle))) == NULL) {
        (void) close(dld_fd);
        return (DLADM_STATUS_NOMEM);
    }

    (*handle)->dld_fd = dld_fd;
    (*handle)->door_fd = -1;

    return (DLADM_STATUS_OK);
}

void
dladm_close(dladm_handle_t handle)
{
    if (handle != NULL) {
        (void) close(handle->dld_fd);
        if (handle->door_fd != -1)
            (void) close(handle->door_fd);
        free(handle);
    }
}

int
dladm_dld_fd(dladm_handle_t handle)
{
    return (handle->dld_fd);
}

/*
 * If DLMGMT_DOOR hasn't been opened in the handle yet, open it.
 */
dladm_status_t
dladm_door_fd(dladm_handle_t handle, int *door_fd)
{
    int fd;

    if (handle->door_fd == -1) {
        if ((fd = open(DLMGMT_DOOR, O_RDONLY)) < 0)
            return (dladm_errno2status(errno));
        handle->door_fd = fd;
    }
    *door_fd = handle->door_fd;

    return (DLADM_STATUS_OK);
}

const char *
dladm_status2str(dladm_status_t status, char *buf)
{
    const char  *s;

    switch (status) {
    case DLADM_STATUS_OK:
        s = "ok";
        break;
    case DLADM_STATUS_BADARG:
        s = "invalid argument";
        break;
    case DLADM_STATUS_FAILED:
        s = "operation failed";
        break;
    case DLADM_STATUS_TOOSMALL:
        s = "buffer size too small";
        break;
    case DLADM_STATUS_NOTSUP:
        s = "operation not supported";
        break;
    case DLADM_STATUS_NOTFOUND:
        s = "object not found";
        break;
    case DLADM_STATUS_BADVAL:
        s = "invalid value";
        break;
    case DLADM_STATUS_NOMEM:
        s = "insufficient memory";
        break;
    case DLADM_STATUS_EXIST:
        s = "object already exists";
        break;
    case DLADM_STATUS_LINKINVAL:
        s = "invalid link";
        break;
    case DLADM_STATUS_PROPRDONLY:
        s = "read-only property";
        break;
    case DLADM_STATUS_BADVALCNT:
        s = "invalid number of values";
        break;
    case DLADM_STATUS_DBNOTFOUND:
        s = "database not found";
        break;
    case DLADM_STATUS_DENIED:
        s = "permission denied";
        break;
    case DLADM_STATUS_IOERR:
        s = "I/O error";
        break;
    case DLADM_STATUS_TEMPONLY:
        s = "change cannot be persistent";
        break;
    case DLADM_STATUS_TIMEDOUT:
        s = "operation timed out";
        break;
    case DLADM_STATUS_ISCONN:
        s = "already connected";
        break;
    case DLADM_STATUS_NOTCONN:
        s = "not connected";
        break;
    case DLADM_STATUS_REPOSITORYINVAL:
        s = "invalid configuration repository";
        break;
    case DLADM_STATUS_MACADDRINVAL:
        s = "invalid MAC address";
        break;
    case DLADM_STATUS_KEYINVAL:
        s = "invalid key";
        break;
    case DLADM_STATUS_INVALIDMACADDRLEN:
        s = "invalid MAC address length";
        break;
    case DLADM_STATUS_INVALIDMACADDRTYPE:
        s = "invalid MAC address type";
        break;
    case DLADM_STATUS_LINKBUSY:
        s = "link busy";
        break;
    case DLADM_STATUS_VIDINVAL:
        s = "invalid VLAN identifier";
        break;
    case DLADM_STATUS_TRYAGAIN:
        s = "try again later";
        break;
    case DLADM_STATUS_NONOTIF:
        s = "link notification is not supported";
        break;
    case DLADM_STATUS_BADTIMEVAL:
        s = "invalid time range";
        break;
    case DLADM_STATUS_INVALIDMACADDR:
        s = "invalid MAC address value";
        break;
    case DLADM_STATUS_INVALIDMACADDRNIC:
        s = "MAC address reserved for use by underlying data-link";
        break;
    case DLADM_STATUS_INVALIDMACADDRINUSE:
        s = "MAC address is already in use";
        break;
    case DLADM_STATUS_MACFACTORYSLOTINVALID:
        s = "invalid factory MAC address slot";
        break;
    case DLADM_STATUS_MACFACTORYSLOTUSED:
        s = "factory MAC address slot already used";
        break;
    case DLADM_STATUS_MACFACTORYSLOTALLUSED:
        s = "all factory MAC address slots are in use";
        break;
    case DLADM_STATUS_MACFACTORYNOTSUP:
        s = "factory MAC address slots not supported";
        break;
    case DLADM_STATUS_INVALIDMACPREFIX:
        s = "Invalid MAC address prefix value";
        break;
    case DLADM_STATUS_INVALIDMACPREFIXLEN:
        s = "Invalid MAC address prefix length";
        break;
    case DLADM_STATUS_CPUMAX:
        s = "non-existent processor ID";
        break;
    case DLADM_STATUS_CPUERR:
        s = "could not determine processor status";
        break;
    case DLADM_STATUS_CPUNOTONLINE:
        s = "processor not online";
        break;
    case DLADM_STATUS_DB_NOTFOUND:
        s = "database not found";
        break;
    case DLADM_STATUS_DB_PARSE_ERR:
        s = "database parse error";
        break;
    case DLADM_STATUS_PROP_PARSE_ERR:
        s = "property parse error";
        break;
    case DLADM_STATUS_ATTR_PARSE_ERR:
        s = "attribute parse error";
        break;
    case DLADM_STATUS_FLOW_DB_ERR:
        s = "flow database error";
        break;
    case DLADM_STATUS_FLOW_DB_OPEN_ERR:
        s = "flow database open error";
        break;
    case DLADM_STATUS_FLOW_DB_PARSE_ERR:
        s = "flow database parse error";
        break;
    case DLADM_STATUS_FLOWPROP_DB_PARSE_ERR:
        s = "flow property database parse error";
        break;
    case DLADM_STATUS_FLOW_ADD_ERR:
        s = "flow add error";
        break;
    case DLADM_STATUS_FLOW_WALK_ERR:
        s = "flow walk error";
        break;
    case DLADM_STATUS_FLOW_IDENTICAL:
        s = "a flow with identical attributes exists";
        break;
    case DLADM_STATUS_FLOW_INCOMPATIBLE:
        s = "flow(s) with incompatible attributes exists";
        break;
    case DLADM_STATUS_FLOW_EXISTS:
        s = "link still has flows";
        break;
    case DLADM_STATUS_PERSIST_FLOW_EXISTS:
        s = "persistent flow with the same name exists";
        break;
    case DLADM_STATUS_INVALID_IP:
        s = "invalid IP address";
        break;
    case DLADM_STATUS_INVALID_PREFIXLEN:
        s = "invalid IP prefix length";
        break;
    case DLADM_STATUS_INVALID_PROTOCOL:
        s = "invalid IP protocol";
        break;
    case DLADM_STATUS_INVALID_PORT:
        s = "invalid port number";
        break;
    case DLADM_STATUS_INVALID_DSF:
        s = "invalid dsfield";
        break;
    case DLADM_STATUS_INVALID_DSFMASK:
        s = "invalid dsfield mask";
        break;
    case DLADM_STATUS_INVALID_MACMARGIN:
        s = "MTU check failed, use lower MTU or -f option";
        break;
    case DLADM_STATUS_BADPROP:
        s = "invalid property";
        break;
    case DLADM_STATUS_MINMAXBW:
        s = "minimum value for maxbw is 1.2M";
        break;
    case DLADM_STATUS_NO_HWRINGS:
        s = "request hw rings failed";
        break;
    case DLADM_STATUS_PERMONLY:
        s = "change must be persistent";
        break;
    case DLADM_STATUS_OPTMISSING:
        s = "optional software not installed";
        break;
    default:
        s = "<unknown error>";
        break;
    }
    (void) snprintf(buf, DLADM_STRSIZE, "%s", dgettext(TEXT_DOMAIN, s));
    return (buf);
}

/*
 * Convert a unix errno to a dladm_status_t.
 * We only convert errnos that are likely to be encountered. All others
 * are mapped to DLADM_STATUS_FAILED.
 */
dladm_status_t
dladm_errno2status(int err)
{
    switch (err) {
    case 0:
        return (DLADM_STATUS_OK);
    case EINVAL:
        return (DLADM_STATUS_BADARG);
    case EEXIST:
        return (DLADM_STATUS_EXIST);
    case ENOENT:
        return (DLADM_STATUS_NOTFOUND);
    case ENOSPC:
        return (DLADM_STATUS_TOOSMALL);
    case ENOMEM:
        return (DLADM_STATUS_NOMEM);
    case ENOTSUP:
        return (DLADM_STATUS_NOTSUP);
    case ENETDOWN:
        return (DLADM_STATUS_NONOTIF);
    case EACCES:
    case EPERM:
        return (DLADM_STATUS_DENIED);
    case EIO:
        return (DLADM_STATUS_IOERR);
    case EBUSY:
        return (DLADM_STATUS_LINKBUSY);
    case EAGAIN:
        return (DLADM_STATUS_TRYAGAIN);
    case ENOTEMPTY:
        return (DLADM_STATUS_FLOW_EXISTS);
    case EOPNOTSUPP:
        return (DLADM_STATUS_FLOW_INCOMPATIBLE);
    case EALREADY:
        return (DLADM_STATUS_FLOW_IDENTICAL);
    default:
        return (DLADM_STATUS_FAILED);
    }
}

boolean_t
dladm_str2interval(char *oarg, uint32_t *interval)
{
    int     val;
    char        *endp = NULL;

    errno = 0;
    val = strtol(oarg, &endp, 10);
    if (errno != 0 || val <= 0 || *endp != '\0')
        return (B_FALSE);

    *interval = val;

    return (B_TRUE);
}

dladm_status_t
dladm_str2bw(char *oarg, uint64_t *bw)
{
    char        *endp = NULL;
    int64_t     n;
    int     mult = 1;

    n = strtoull(oarg, &endp, 10);

    if ((errno != 0) || (strlen(endp) > 1))
        return (DLADM_STATUS_BADARG);

    if (n < 0)
        return (DLADM_STATUS_BADVAL);

    switch (*endp) {
    case 'k':
    case 'K':
        mult = 1000;
        break;
    case 'm':
    case 'M':
    case '\0':
        mult = 1000000;
        break;
    case 'g':
    case 'G':
        mult = 1000000000;
        break;
    case '%':
        /*
         * percentages not supported for now,
         * see RFE 6540675
         */
        return (DLADM_STATUS_NOTSUP);
    default:
        return (DLADM_STATUS_BADVAL);
    }

    *bw = n * mult;

    /* check for overflow */
    if (*bw / mult != n)
        return (DLADM_STATUS_BADARG);

    return (DLADM_STATUS_OK);
}

/*
 * Convert bandwidth in bps to a string in mpbs.  For values greater
 * than 1mbps or 1000000, print a whole mbps value.  For values that
 * have fractional Mbps in whole Kbps , print the bandwidth in a manner
 * simlilar to a floating point format.
 *
 *        bps       string
 *          0            0
 *        100            0
 *       2000        0.002
 *     431000        0.431
 *    1000000            1
 *    1030000        1.030
 *  100000000          100
 */
const char *
dladm_bw2str(int64_t bw, char *buf)
{
    int kbps, mbps;

    kbps = (bw%1000000)/1000;
    mbps = bw/1000000;
    if (kbps != 0) {
        if (mbps == 0)
            (void) snprintf(buf, DLADM_STRSIZE, "0.%03u", kbps);
        else
            (void) snprintf(buf, DLADM_STRSIZE, "%5u.%03u", mbps,
                kbps);
    } else {
        (void) snprintf(buf, DLADM_STRSIZE, "%5u", mbps);
    }

    return (buf);
}

#define LOCK_DB_PERMS   S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH

static int
i_dladm_lock_db(const char *lock_file, short type)
{
    int lock_fd;
    struct  flock lock;

    if ((lock_fd = open(lock_file, O_RDWR | O_CREAT | O_TRUNC,
        LOCK_DB_PERMS)) < 0)
        return (-1);

    lock.l_type = type;
    lock.l_whence = SEEK_SET;
    lock.l_start = 0;
    lock.l_len = 0;

    if (fcntl(lock_fd, F_SETLKW, &lock) < 0) {
        int err = errno;

        (void) close(lock_fd);
        (void) unlink(lock_file);
        errno = err;
        return (-1);
    }
    return (lock_fd);
}

static void
i_dladm_unlock_db(const char *lock_file, int fd)
{
    struct flock lock;

    if (fd < 0)
        return;

    lock.l_type = F_UNLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = 0;
    lock.l_len = 0;

    (void) fcntl(fd, F_SETLKW, &lock);
    (void) close(fd);
    (void) unlink(lock_file);
}

/*
 * Given a link class, returns its class string.
 */
const char *
dladm_class2str(datalink_class_t class, char *buf)
{
    const char *s;

    switch (class) {
    case DATALINK_CLASS_PHYS:
        s = "phys";
        break;
    case DATALINK_CLASS_VLAN:
        s = "vlan";
        break;
    case DATALINK_CLASS_AGGR:
        s = "aggr";
        break;
    case DATALINK_CLASS_VNIC:
        s = "vnic";
        break;
    case DATALINK_CLASS_ETHERSTUB:
        s = "etherstub";
        break;
    case DATALINK_CLASS_SIMNET:
        s = "simnet";
        break;
    case DATALINK_CLASS_BRIDGE:
        s = "bridge";
        break;
    default:
        s = "unknown";
        break;
    }

    (void) snprintf(buf, DLADM_STRSIZE, "%s", s);
    return (buf);
}

/*
 * Given a physical link media type, returns its media type string.
 */
const char *
dladm_media2str(uint32_t media, char *buf)
{
    const char *s = "--";
    media_type_t *mt;
    int idx;

    for (idx = 0; idx < MEDIATYPECOUNT; idx++) {
        mt = media_type_table + idx;
        if (mt->media_type == media) {
            s = mt->media_type_str;
            break;
        }
    }

    (void) snprintf(buf, DLADM_STRSIZE, "%s", s);
    return (buf);
}

/*
 * Given a physical link media type string, returns its media type constant.
 */
uint32_t
dladm_str2media(const char *buf)
{
    media_type_t *mt;
    int idx;

    for (idx = 0; idx < MEDIATYPECOUNT; idx++) {
        mt = media_type_table + idx;
        if (strcasecmp(buf, mt->media_type_str) == 0)
            return (mt->media_type);
    }

    return (DL_OTHER);
}

dladm_status_t
i_dladm_rw_db(dladm_handle_t handle, const char *db_file, mode_t db_perms,
    dladm_status_t (*process_db)(dladm_handle_t, void *, FILE *, FILE *),
    void *arg, boolean_t writeop)
{
    dladm_status_t  status = DLADM_STATUS_OK;
    FILE        *fp, *nfp = NULL;
    char        lock[MAXPATHLEN];
    char        file[MAXPATHLEN];
    char        newfile[MAXPATHLEN];
    char        *db_basename;
    int     nfd, lock_fd;

    /*
     * If we are called from a boot script such as net-physical,
     * it's quite likely that the root fs is still not writable.
     * For this case, it's ok for the lock creation to fail since
     * no one else could be accessing our configuration file.
     */
    db_basename = strrchr(db_file, '/');
    if (db_basename == NULL || db_basename[1] == '\0')
        return (dladm_errno2status(EINVAL));
    db_basename++;
    (void) snprintf(lock, MAXPATHLEN, "/tmp/%s.lock", db_basename);
    if ((lock_fd = i_dladm_lock_db
        (lock, (writeop ? F_WRLCK : F_RDLCK))) < 0 && errno != EROFS)
        return (dladm_errno2status(errno));

    (void) snprintf(file, MAXPATHLEN, "%s/%s", dladm_rootdir, db_file);
    if ((fp = fopen(file, (writeop ? "r+" : "r"))) == NULL) {
        int err = errno;

        i_dladm_unlock_db(lock, lock_fd);
        if (err == ENOENT)
            return (DLADM_STATUS_DBNOTFOUND);

        return (dladm_errno2status(err));
    }

    if (writeop) {
        (void) snprintf(newfile, MAXPATHLEN, "%s/%s.new",
            dladm_rootdir, db_file);
        if ((nfd = open(newfile, O_WRONLY | O_CREAT | O_TRUNC,
            db_perms)) < 0) {
            (void) fclose(fp);
            i_dladm_unlock_db(lock, lock_fd);
            return (dladm_errno2status(errno));
        }

        if ((nfp = fdopen(nfd, "w")) == NULL) {
            (void) close(nfd);
            (void) fclose(fp);
            (void) unlink(newfile);
            i_dladm_unlock_db(lock, lock_fd);
            return (dladm_errno2status(errno));
        }
    }
    status = (*process_db)(handle, arg, fp, nfp);
    if (!writeop || status != DLADM_STATUS_OK)
        goto done;

    /*
     * Configuration files need to be owned by the 'dladm' user.
     * If we are invoked by root, the file ownership needs to be fixed.
     */
    if (getuid() == 0 || geteuid() == 0) {
        if (fchown(nfd, UID_DLADM, GID_SYS) < 0) {
            status = dladm_errno2status(errno);
            goto done;
        }
    }

    if (fflush(nfp) == EOF) {
        status = dladm_errno2status(errno);
        goto done;
    }
    (void) fclose(fp);
    (void) fclose(nfp);

    if (rename(newfile, file) < 0) {
        (void) unlink(newfile);
        i_dladm_unlock_db(lock, lock_fd);
        return (dladm_errno2status(errno));
    }

    i_dladm_unlock_db(lock, lock_fd);
    return (DLADM_STATUS_OK);

done:
    if (nfp != NULL) {
        (void) fclose(nfp);
        if (status != DLADM_STATUS_OK)
            (void) unlink(newfile);
    }
    (void) fclose(fp);
    i_dladm_unlock_db(lock, lock_fd);
    return (status);
}

dladm_status_t
dladm_set_rootdir(const char *rootdir)
{
    DIR *dp;

    if (rootdir == NULL || *rootdir != '/' ||
        (dp = opendir(rootdir)) == NULL)
        return (DLADM_STATUS_BADARG);

    (void) strncpy(dladm_rootdir, rootdir, MAXPATHLEN);
    (void) closedir(dp);
    return (DLADM_STATUS_OK);
}

boolean_t
dladm_valid_linkname(const char *link)
{
    size_t      len = strlen(link);
    const char  *cp;

    if (len + 1 >= MAXLINKNAMELEN)
        return (B_FALSE);

    /*
     * The link name cannot start with a digit and must end with a digit.
     */
    if ((isdigit(link[0]) != 0) || (isdigit(link[len - 1]) == 0))
        return (B_FALSE);

    /*
     * The legal characters in a link name are:
     * alphanumeric (a-z,  A-Z,  0-9), and the underscore ('_').
     */
    for (cp = link; *cp != '\0'; cp++) {
        if ((isalnum(*cp) == 0) && (*cp != '_'))
            return (B_FALSE);
    }

    return (B_TRUE);
}

/*
 * Convert priority string to a value.
 */
dladm_status_t
dladm_str2pri(char *token, mac_priority_level_t *pri)
{
    if (strlen(token) == strlen("low") &&
        strncasecmp(token, "low", strlen("low")) == 0) {
        *pri = MPL_LOW;
    } else if (strlen(token) == strlen("medium") &&
        strncasecmp(token, "medium", strlen("medium")) == 0) {
        *pri = MPL_MEDIUM;
    } else if (strlen(token) == strlen("high") &&
        strncasecmp(token, "high", strlen("high")) == 0) {
        *pri = MPL_HIGH;
    } else {
        return (DLADM_STATUS_BADVAL);
    }
    return (DLADM_STATUS_OK);
}

/*
 * Convert priority value to a string.
 */
const char *
dladm_pri2str(mac_priority_level_t pri, char *buf)
{
    const char  *s;

    switch (pri) {
    case MPL_LOW:
        s = "low";
        break;
    case MPL_MEDIUM:
        s = "medium";
        break;
    case MPL_HIGH:
        s = "high";
        break;
    default:
        s = "--";
        break;
    }
    (void) snprintf(buf, DLADM_STRSIZE, "%s", dgettext(TEXT_DOMAIN, s));
    return (buf);
}

void
dladm_free_args(dladm_arg_list_t *list)
{
    if (list != NULL) {
        free(list->al_buf);
        free(list);
    }
}

dladm_status_t
dladm_parse_args(char *str, dladm_arg_list_t **listp, boolean_t novalues)
{
    dladm_arg_list_t    *list;
    dladm_arg_info_t    *aip;
    char            *buf, *curr;
    int         len, i;

    if (str == NULL)
        return (DLADM_STATUS_BADVAL);

    if (str[0] == '\0')
        return (DLADM_STATUS_OK);

    list = malloc(sizeof (dladm_arg_list_t));
    if (list == NULL)
        return (dladm_errno2status(errno));

    list->al_count = 0;
    list->al_buf = buf = strdup(str);
    if (buf == NULL)
        return (dladm_errno2status(errno));

    curr = buf;
    len = strlen(buf);
    aip = NULL;
    for (i = 0; i < len; i++) {
        char        c = buf[i];
        boolean_t   match = (c == '=' || c == ',');

        if (!match && i != len - 1)
            continue;

        if (match) {
            buf[i] = '\0';
            if (*curr == '\0')
                goto fail;
        }

        if (aip != NULL && c != '=') {
            if (aip->ai_count > DLADM_MAX_ARG_VALS)
                goto fail;

            if (novalues)
                goto fail;

            aip->ai_val[aip->ai_count] = curr;
            aip->ai_count++;
        } else {
            if (list->al_count > DLADM_MAX_ARG_VALS)
                goto fail;

            aip = &list->al_info[list->al_count];
            aip->ai_name = curr;
            aip->ai_count = 0;
            list->al_count++;
            if (c == ',')
                aip = NULL;
        }
        curr = buf + i + 1;
    }

    *listp = list;
    return (DLADM_STATUS_OK);

fail:
    dladm_free_args(list);
    return (DLADM_STATUS_FAILED);
}