libntsvcs/common/dfs.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) 2010, 2012, Oracle and/or its affiliates. All rights reserved.
 */

#include <strings.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <dlfcn.h>
#include <pthread.h>
#include <syslog.h>
#include <assert.h>
#include <libgen.h>
#include <note.h>
#include <sys/fs_reparse.h>
#include <uuid/uuid.h>

#include <smbsrv/libsmb.h>
#include <smbsrv/libntsvcs.h>
#include <smbsrv/smb_dfs.h>
#include <smbsrv/smb_share.h>

#include "smb_reparse.h"
#include "dfs.h"

static void *dfs_intr_hdl = NULL;

static struct {
    int (*dfsops_remote_count)(uint32_t *);
} dfs_intr_ops;

/*
 * DFS Namespace
 *
 * Currently, only ONE standalone namespace is supported.
 *
 * ns_name  The name of the exported namespace. This will be the only
 *      exported namespace until hosting multiple namespaces
 *      is supported.
 *
 * ns_path  The filesystem path of the root share.
 *
 * ns_exported  B_TRUE if a standalone namespace is exported
 *
 * ns_cache Caches links' UNC and filesystem path where
 *      the key is the UNC path.
 */
typedef struct dfs_ns {
    rwlock_t    ns_lock;
    char        ns_name[MAXNAMELEN];
    char        ns_path[MAXPATHLEN];
    uint32_t    ns_type;
    boolean_t   ns_exported;
    smb_avl_t   *ns_cache;
} dfs_ns_t;

dfs_ns_t dfsns;

/*
 * Namespace cache node operations
 */
static int dfs_node_cmp(const void *, const void *);
static dfs_node_t *dfs_node_create(const char *, const char *, uint32_t);
static void dfs_node_destroy(void *);

static smb_avl_nops_t dfs_node_ops = {
    dfs_node_cmp,       /* compare */
    NULL,           /* add */
    dfs_node_destroy,   /* remove */
    NULL,           /* hold */
    NULL,           /* rele */
    dfs_node_destroy    /* flush */
};

/*
 * System's NetBIOS name
 */
static char dfs_nbname[NETBIOS_NAME_SZ];

/*
 * Lock for accessing root information (extended attribute)
 */
static rwlock_t dfs_root_rwl;

static struct {
    uint32_t    ns_type;
    const char  *svc_name;
} dfs_ns_info[] = {
    { SMB_NS_DFS,   DFS_REPARSE_SVCTYPE },
    { SMB_NS_FEDFS, DFS_FEDFS_SVCTYPE }
};

#define DFS_NS_NUM (sizeof (dfs_ns_info)/sizeof (dfs_ns_info[0]))

#define DFS_NS_EXPORTED(n) (dfsns.ns_exported && \
    (((n) == NULL) || (smb_strcasecmp((n), dfsns.ns_name, 0) == 0)))

extern uint32_t srvsvc_shr_setdfsroot(smb_share_t *, boolean_t);

/*
 * Namespace functions
 */
static void dfs_ns_load(const char *, const char *);
static void dfs_ns_unload(const char *);
static void dfs_ns_cleanup(const char *, uint32_t);
static uint32_t dfs_ns_path(const char *, char *, size_t, uint32_t);
static void dfs_ns_populate_cache(const char *, const char *);

/*
 * Root functions
 */
static int dfs_root_add(const char *, dfs_info_t *);
static uint32_t dfs_root_remove(const char *);
static uint32_t dfs_root_encode(dfs_info_t *, char **, size_t *);
static uint32_t dfs_root_decode(dfs_info_t *, char *, size_t, uint32_t);
static uint32_t dfs_root_isvalidstate(uint32_t);

static int dfs_root_xopen(const char *, int);
static void dfs_root_xclose(int);
static uint32_t dfs_root_xwrite(int, dfs_info_t *);
static uint32_t dfs_root_xread(int, dfs_info_t *, uint32_t);

/*
 * Link functions
 */
static uint32_t dfs_link_commit(const char *, dfs_info_t *, uint32_t);
static boolean_t dfs_link_isvalidstate(uint32_t);

/*
 * Target functions
 */
static void dfs_target_init(dfs_target_t *, const char *, const char *,
    uint32_t);
static int dfs_target_find(dfs_target_t *, uint32_t, const char *,
    const char *);
static boolean_t dfs_target_isvalidstate(uint32_t);

/*
 * Utility functions
 */
static boolean_t dfs_path_isdir(const char *);
static void dfs_path_create(const char *);
static void dfs_path_remove(smb_unc_t *, uint32_t);
static uint32_t dfs_modinfo(uint32_t, dfs_info_t *, dfs_info_t *, uint32_t);
static boolean_t dfs_isvalid_nstype(uint32_t);
static const char *dfs_svc_name(uint32_t);
static uint32_t dfs_ns_type(const char *);

/*
 * DFS module initialization:
 *
 * - gets system's NetBIOS name
 * - installs interposition ops
 */
void
dfs_init(void)
{
    smb_domain_t di;

    if (!smb_domain_lookup_type(SMB_DOMAIN_LOCAL, &di))
        return;

    (void) strlcpy(dfs_nbname, di.di_nbname, NETBIOS_NAME_SZ);

    bzero((void *)&dfs_intr_ops, sizeof (dfs_intr_ops));

    if ((dfs_intr_hdl = smb_dlopen()) == NULL)
        return;

    if ((dfs_intr_ops.dfsops_remote_count =
        (int (*)())dlsym(dfs_intr_hdl, "smb_dfs_remote_count")) == NULL) {
        smb_dlclose(dfs_intr_hdl);
        dfs_intr_hdl = NULL;
        bzero((void *)&dfs_intr_ops, sizeof (dfs_intr_ops));
    }
}

/*
 * DFS module cleanup:
 *
 * - destroys the namespace cache
 */
void
dfs_fini(void)
{
    smb_dlclose(dfs_intr_hdl);
    dfs_ns_unexport(NULL);
}

/*
 * To successfully handle some of link/root requests, some
 * file system operations need to be performed. These operations
 * should take place on behalf of the connected user (typically
 * Administrator) and to do so we need to have an infrastructure
 * in place so that smbd can act as a client and sends request to
 * the kernel. Right now, we lack this infrastructure, so we make
 * a compromise by temporarily enabling some privileges for smbd
 * to be able to fulfill various link/root requests.
 */
void
dfs_setpriv(priv_op_t op)
{
    (void) priv_set(op, PRIV_EFFECTIVE,
        PRIV_FILE_DAC_READ,
        PRIV_FILE_DAC_WRITE,
        PRIV_FILE_DAC_EXECUTE,
        PRIV_FILE_DAC_SEARCH, NULL);
}

/*
 * ========================
 * Namespace API (public)
 * ========================
 */

/*
 * Sets up a dfs_ns_t structure for the specified namespace
 * (root share) if a namespace hasn't already been exported.
 */
void *
dfs_ns_export(void *arg)
{
    char *share = arg;
    smb_share_t si;
    dfs_info_t info;

    (void) rw_wrlock(&dfsns.ns_lock);

    if (dfsns.ns_exported) {
        if (smb_strcasecmp(dfsns.ns_name, share, 0) != 0) {
            syslog(LOG_WARNING, "dfs: trying to export %s."
                " Only one standalone namespace is supported."
                " A namespace is already exported for %s:%s.",
                share, dfs_svc_name(dfsns.ns_type), dfsns.ns_name);
        }
        (void) rw_unlock(&dfsns.ns_lock);
        free(share);
        return (NULL);
    }

    if (smb_share_lookup(share, &si) != NERR_Success) {
        (void) rw_unlock(&dfsns.ns_lock);
        free(share);
        return (NULL);
    }

    if ((si.shr_flags & SMB_SHRF_DFSROOT) == 0) {
        (void) rw_unlock(&dfsns.ns_lock);
        smb_share_free(&si);
        free(share);
        return (NULL);
    }

    if (dfs_root_getinfo(si.shr_path, &info,
        DFS_INFO_LEVEL_ALL, SMB_NS_ANY) != ERROR_SUCCESS) {
        (void) rw_unlock(&dfsns.ns_lock);
        smb_share_free(&si);
        free(share);
        return (NULL);
    }

    (void) strlcpy(dfsns.ns_name, share, sizeof (dfsns.ns_name));
    (void) strlcpy(dfsns.ns_path, si.shr_path, sizeof (dfsns.ns_path));
    dfsns.ns_type = info.i_ns_type;
    dfs_ns_load(share, si.shr_path);
    dfsns.ns_exported = B_TRUE;

    (void) rw_unlock(&dfsns.ns_lock);
    dfs_info_free(&info);
    smb_share_free(&si);
    free(share);
    return (NULL);
}

/*
 * If the specified namespace is exported, the cache
 * will be destroyed and the namespace is marked as
 * not exported.
 *
 * If no name is specified then the active namespace
 * will be unexported if there is one.
 */
void
dfs_ns_unexport(const char *name)
{
    (void) rw_wrlock(&dfsns.ns_lock);

    if (DFS_NS_EXPORTED(name)) {
        dfs_ns_unload(name);
        *dfsns.ns_name = '\0';
        *dfsns.ns_path = '\0';
        dfsns.ns_type = 0;
        dfsns.ns_exported = B_FALSE;
    }

    (void) rw_unlock(&dfsns.ns_lock);
}

/*
 * Returns the file system path for the given namespace.
 */
static uint32_t
dfs_ns_path(const char *name, char *path, size_t pathsz, uint32_t ns_type)
{
    uint32_t status;

    if (name == NULL)
        return (ERROR_INVALID_PARAMETER);

    (void) rw_rdlock(&dfsns.ns_lock);

    if (DFS_NS_EXPORTED(name) && dfsns.ns_type == ns_type) {
        (void) strlcpy(path, dfsns.ns_path, pathsz);
        status = ERROR_SUCCESS;
    } else {
        status = ERROR_NOT_FOUND;
    }

    (void) rw_unlock(&dfsns.ns_lock);

    return (status);
}

/*
 * Returns the number of DFS root shares i.e. the number
 * of standalone namespaces.
 *
 * The caller must be holding the namespace lock (dfsns.ns_lock)
 * for at least reading.
 */
uint32_t
dfs_ns_count(void)
{
    uint32_t nroot = 0;
    int rc;

    if (dfs_intr_ops.dfsops_remote_count != NULL &&
        (rc = dfs_intr_ops.dfsops_remote_count(&nroot)) != 0) {
        /*
         * If this call fails, let's assume there's at least one root
         * namespace already configured.  The interposer library cannot
         * confirm or deny the presence of a namespace, so let's take
         * the safe approach and assume one exists.
         */
        nroot = 1;
        syslog(LOG_WARNING, "dfs: dfsops_remote_count() failed: %d, "
            "assuming one namespace exists", rc);
    }

    if (dfsns.ns_exported)
        nroot++;

    return (nroot);
}

/*
 * Creates a DFS root with the given name and comment.
 *
 * This function does not create the root share, it
 * should already exist.
 */
uint32_t
dfs_ns_create(const char *rootshr, const char *cmnt, uint32_t ns_type)
{
    dfs_info_t info;
    dfs_target_t t;
    smb_share_t si;
    uuid_t uuid;
    uint32_t status;

    if (*rootshr == '\\') {
        /* Windows has a special case here! */
        return (ERROR_BAD_PATHNAME);
    }

    if (!dfs_isvalid_nstype(ns_type))
        return (ERROR_NOT_SUPPORTED);

    (void) rw_wrlock(&dfsns.ns_lock);

    /* For now only allow a single standalone namespace */
    if (dfs_ns_count() > 0) {
        (void) rw_unlock(&dfsns.ns_lock);
        return (ERROR_NOT_SUPPORTED);
    }

    if (dfsns.ns_exported) {
        if (dfsns.ns_type != ns_type) {
            syslog(LOG_WARNING,
                "dfs: trying to create %s:%s namespace."
                " Only one standalone namespace is supported."
                " A namespace is already exported for %s:%s",
                dfs_svc_name(ns_type), rootshr,
                dfs_svc_name(dfsns.ns_type), dfsns.ns_name);
            (void) rw_unlock(&dfsns.ns_lock);
            return (ERROR_NOT_SUPPORTED);
        }

        if (smb_strcasecmp(dfsns.ns_name, rootshr, 0) == 0) {
            /* This DFS root is already exported */
            (void) rw_unlock(&dfsns.ns_lock);
            return (ERROR_FILE_EXISTS);
        }

        syslog(LOG_WARNING, "dfs: trying to create %s namespace."
            " Only one standalone namespace is supported."
            " A namespace is already exported for %s:%s.",
            rootshr, dfs_svc_name(dfsns.ns_type), dfsns.ns_name);
        (void) rw_unlock(&dfsns.ns_lock);
        return (ERROR_NOT_SUPPORTED);
    }

    if (smb_share_lookup(rootshr, &si) != NERR_Success) {
        (void) rw_unlock(&dfsns.ns_lock);
        return (NERR_NetNameNotFound);
    }

    bzero(&info, sizeof (info));
    if (cmnt)
        (void) strlcpy(info.i_comment, cmnt, sizeof (info.i_comment));
    info.i_ns_type = ns_type;
    info.i_state = DFS_VOLUME_STATE_OK | DFS_VOLUME_FLAVOR_STANDALONE;
    info.i_timeout = DFS_ROOT_TIMEOUT;
    info.i_propflags = 0;

    uuid_generate_random(uuid);
    uuid_unparse(uuid, info.i_guid);

    dfs_target_init(&t, dfs_nbname, rootshr, DFS_STORAGE_STATE_ONLINE);

    info.i_ntargets = 1;
    info.i_targets = &t;

    if ((status = dfs_root_add(si.shr_path, &info)) != ERROR_SUCCESS) {
        (void) rw_unlock(&dfsns.ns_lock);
        smb_share_free(&si);
        return (status);
    }

    status = srvsvc_shr_setdfsroot(&si, B_TRUE);
    if (status == ERROR_SUCCESS) {
        (void) strlcpy(dfsns.ns_name, rootshr, sizeof (dfsns.ns_name));
        (void) strlcpy(dfsns.ns_path, si.shr_path,
            sizeof (dfsns.ns_path));
        dfsns.ns_type = ns_type;
        dfs_ns_load(rootshr, si.shr_path);
        dfsns.ns_exported = B_TRUE;
    }
    (void) rw_unlock(&dfsns.ns_lock);

    smb_share_free(&si);
    return (status);
}

/*
 * Removes the namespace and all the links in it.
 */
uint32_t
dfs_ns_destroy(const char *name, uint32_t ns_type)
{
    smb_share_t si;
    dfs_info_t info;
    uint32_t status;

    if (smb_share_lookup(name, &si) != NERR_Success)
        return (ERROR_NOT_FOUND);

    if ((si.shr_flags & SMB_SHRF_DFSROOT) == 0) {
        smb_share_free(&si);
        return (ERROR_NOT_FOUND);
    }

    if (dfs_root_getinfo(si.shr_path, &info,
        DFS_INFO_LEVEL_ALL, SMB_NS_ANY) != ERROR_SUCCESS) {
        smb_share_free(&si);
        return (ERROR_NOT_FOUND);
    }

    if (info.i_ns_type != ns_type) {
        dfs_info_free(&info);
        smb_share_free(&si);
        return (ERROR_NOT_FOUND);
    }

    dfs_info_free(&info);

    status = srvsvc_shr_setdfsroot(&si, B_FALSE);
    if (status != ERROR_SUCCESS) {
        syslog(LOG_WARNING, "dfs: failed to disable root share %s (%d)",
            name, status);
        smb_share_free(&si);
        return (status);
    }

    if ((status = dfs_root_remove(si.shr_path)) != ERROR_SUCCESS) {
        smb_share_free(&si);
        return (status);
    }

    /*
     * do not remove links for fedfs namespaces
     * When fedfs namespaces are destroyed, the
     * entire dataset will be destroyed.
     */
    if (ns_type != SMB_NS_FEDFS)
        dfs_ns_cleanup(si.shr_path, ns_type);
    dfs_ns_unexport(name);
    smb_share_free(&si);

    return (ERROR_SUCCESS);
}

/*
 * Determines the DFS namespace flavor.
 */
uint32_t
dfs_ns_getflavor(const char *name, uint32_t ns_type)
{
    char rootdir[DFS_PATH_MAX];
    dfs_info_t info;

    if (dfs_ns_path(name, rootdir, DFS_PATH_MAX, ns_type) != ERROR_SUCCESS)
        return (0);

    /* get flavor info from state info (info level 2) */
    if (dfs_root_getinfo(rootdir, &info, 2, ns_type) != ERROR_SUCCESS)
        return (0);

    return (info.i_state & DFS_VOLUME_FLAVORS);
}

/*
 * Adds the given target to the link in the specified namespace.
 * It will update the cache if this is a new link
 */
uint32_t
dfs_ns_addlink(const char *name, dfs_path_t *dfspath, const char *server,
    const char *share, const char *cmnt, uint32_t flags, uint32_t ns_type)
{
    dfs_node_t *dn;
    char uncpath[DFS_PATH_MAX];
    char *fspath = dfspath->p_fspath;
    uint32_t status;
    boolean_t newlink;

    if (name == NULL)
        return (ERROR_INVALID_PARAMETER);

    dfs_path_create(fspath);

    status = dfs_link_add(fspath, server, share, cmnt, flags, &newlink,
        ns_type);
    if (status != ERROR_SUCCESS) {
        dfs_path_remove(&dfspath->p_unc, ns_type);
        return (status);
    }

    if (!newlink)
        return (status);

    (void) rw_wrlock(&dfsns.ns_lock);

    if (DFS_NS_EXPORTED(name) && (dfsns.ns_cache != NULL)) {
        (void) snprintf(uncpath, DFS_PATH_MAX, "\\\\%s\\%s\\%s",
            dfs_nbname, dfspath->p_unc.unc_share,
            dfspath->p_unc.unc_path);

        (void) strsubst(uncpath, '/', '\\');

        dn = dfs_node_create(uncpath, fspath, DFS_OBJECT_LINK);
        if (dn != NULL) {
            if (smb_avl_add(dfsns.ns_cache, dn) != 0)
                dfs_node_destroy(dn);
        }
    }

    (void) rw_unlock(&dfsns.ns_lock);

    return (status);
}

/*
 * Removes the given target from the link in the specified namespace.
 *
 * If the link is removed as a result the cache will be updated.
 */
uint32_t
dfs_ns_removelink(const char *name, dfs_path_t *dfspath,
    const char *server, const char *share, uint32_t ns_type)
{
    dfs_node_t dn;
    uint32_t status, stat;

    if (name == NULL)
        return (ERROR_INVALID_PARAMETER);

    status = dfs_link_remove(dfspath->p_fspath, server, share, ns_type);

    if (status != ERROR_SUCCESS)
        return (status);

    if (dfs_link_stat(dfspath->p_fspath, &stat) != ERROR_SUCCESS)
        return (ERROR_SUCCESS);

    if (!DFS_STAT_ISSMB(stat)) {
        (void) rw_wrlock(&dfsns.ns_lock);

        if (DFS_NS_EXPORTED(name) && (dfsns.ns_cache != NULL)) {
            (void) snprintf(dn.dn_uncpath, sizeof (dn.dn_uncpath),
                "\\\\%s\\%s\\%s", dfs_nbname, name,
                dfspath->p_unc.unc_path);

            /* relpath may contain '/' */
            (void) strsubst(dn.dn_uncpath, '/', '\\');
            smb_avl_remove(dfsns.ns_cache, &dn);
        }

        (void) rw_unlock(&dfsns.ns_lock);
    }

    /*
     * if link is removed then try to remove its
     * empty parent directories if any
     */
    if (stat == DFS_STAT_NOTFOUND)
        dfs_path_remove(&dfspath->p_unc, ns_type);

    return (status);
}

/*
 * Returns the number of links + 1 (for root) in the
 * specified namespace if this is the exported one
 *
 * The caller must be holding the namespace lock
 * (dfsns.ns_lock) for writing.
 */
uint32_t
dfs_ns_numlink(const char *name)
{
    uint32_t num = 0;

    if (DFS_NS_EXPORTED(name)) {
        if (dfsns.ns_cache == NULL)
            dfs_ns_load(dfsns.ns_name, dfsns.ns_path);

        num = smb_avl_numnodes(dfsns.ns_cache);
    }

    return (num);
}

/*
 * Returns B_TRUE if a namespace of the specified
 * type exists in namespace cache.
 *
 * The caller must be holding the namespace lock
 * (dfsns.ns_lock) for at least reading.
 */
boolean_t
dfs_ns_exists(uint32_t ns_type)
{
    if (dfsns.ns_exported && dfsns.ns_type == ns_type)
        return (B_TRUE);
    else
        return (B_FALSE);
}

/*
 * Locks the namespace for writing.
 * Used during iteration.
 */
void
dfs_ns_hold(const char *name)
{
    NOTE(ARGUNUSED(name))

    (void) rw_wrlock(&dfsns.ns_lock);
}

/*
 * Unlocks the namespace
 */
void
dfs_ns_rele(const char *name)
{
    NOTE(ARGUNUSED(name))

    (void) rw_unlock(&dfsns.ns_lock);
}

/*
 * Returns the first node in the namespace cache.
 * The first node in the cache is the root of the
 * namespace.
 *
 * The caller must be holding the namespace lock
 * (dfsns.ns_lock) for at least reading.
 */
dfs_node_t *
dfs_ns_firstlink(const char *name)
{
    NOTE(ARGUNUSED(name))

    return (smb_avl_first(dfsns.ns_cache));
}

/*
 * Returns the next node in the namespace cache after
 * the passed 'node'
 *
 * The caller must be holding the namespace lock
 * (dfsns.ns_lock) for at least reading.
 */
dfs_node_t *
dfs_ns_nextlink(const char *name, dfs_node_t *node)
{
    NOTE(ARGUNUSED(name))

    return (smb_avl_next(dfsns.ns_cache, node));
}

/*
 * ==================
 * Root API (public)
 * ==================
 */

/*
 * Retrieves the information of the root specified by its path.
 *
 * Info level (1) only needs the UNC path which is not stored,
 * it is constructed so the function will return without
 * accessing the backend storage.
 *
 * The dfs root in backend storage must be of the same namespace
 * type as requested.
 */
uint32_t
dfs_root_getinfo(const char *rootdir, dfs_info_t *info, uint32_t infolvl,
    uint32_t ns_type)
{
    uint32_t status = ERROR_INTERNAL_ERROR;
    int xfd;

    bzero(info, sizeof (dfs_info_t));
    info->i_type = DFS_OBJECT_ROOT;

    if (infolvl == 1)
        return (ERROR_SUCCESS);

    (void) rw_rdlock(&dfs_root_rwl);
    if ((xfd = dfs_root_xopen(rootdir, O_RDONLY)) > 0) {
        status = dfs_root_xread(xfd, info, infolvl);
        dfs_root_xclose(xfd);
    }
    (void) rw_unlock(&dfs_root_rwl);

    if (status == ERROR_SUCCESS) {
        if (ns_type != SMB_NS_ANY && info->i_ns_type != ns_type) {
            dfs_info_free(info);
            status = ERROR_NOT_FOUND;
        }
    }
    return (status);
}

/*
 * Sets the provided information for the specified root or root target.
 * Root is specified by 'rootdir' and the target is specified by
 * (t_server, t_share) pair. Only information items needed for given
 * information level (infolvl) is valid in the passed DFS info structure
 * 'info'.
 */
uint32_t
dfs_root_setinfo(const char *rootdir, dfs_info_t *info, uint32_t infolvl,
    uint32_t ns_type)
{
    dfs_info_t curinfo;
    uint32_t status = ERROR_SUCCESS;
    int xfd;

    (void) rw_wrlock(&dfs_root_rwl);
    if ((xfd = dfs_root_xopen(rootdir, O_RDWR)) < 0) {
        (void) rw_unlock(&dfs_root_rwl);
        return (ERROR_INTERNAL_ERROR);
    }

    status = dfs_root_xread(xfd, &curinfo, DFS_INFO_LEVEL_ALL);
    if (status != ERROR_SUCCESS) {
        dfs_root_xclose(xfd);
        (void) rw_unlock(&dfs_root_rwl);
        return (status);
    }

    if (ns_type != SMB_NS_ANY && curinfo.i_ns_type != ns_type) {
        dfs_root_xclose(xfd);
        (void) rw_unlock(&dfs_root_rwl);
        dfs_info_free(&curinfo);
        return (ERROR_NOT_FOUND);
    }

    status = dfs_modinfo(DFS_OBJECT_ROOT, &curinfo, info, infolvl);
    if (status == ERROR_SUCCESS)
        status = dfs_root_xwrite(xfd, &curinfo);

    dfs_root_xclose(xfd);
    (void) rw_unlock(&dfs_root_rwl);

    dfs_info_free(&curinfo);
    return (status);
}

/*
 * ==================
 * Link API (public)
 * ==================
 */

/*
 * Gets the status of the given path as a link
 */
uint32_t
dfs_link_stat(const char *path, uint32_t *stat)
{
    int svctype;

    if (smb_reparse_stat(path, stat) != 0)
        return (ERROR_INTERNAL_ERROR);

    switch (*stat) {
    case SMB_REPARSE_NOTFOUND:
        *stat = DFS_STAT_NOTFOUND;
        break;
    case SMB_REPARSE_NOTREPARSE:
        *stat = DFS_STAT_NOTLINK;
        break;
    case SMB_REPARSE_ISREPARSE:
        *stat = DFS_STAT_ISREPARSE;
        if (smb_reparse_svctype(path, &svctype) == 0) {
            switch (svctype) {
            case SMB_SVCTYPE_DFS:
                *stat = DFS_STAT_ISDFS;
                break;
            case SMB_SVCTYPE_FEDFS:
                *stat = DFS_STAT_ISFEDFS;
                break;
            default:
                break;
            }
        }
        break;
    default:
        *stat = DFS_STAT_UNKNOWN;
        break;
    }

    return (ERROR_SUCCESS);
}

/*
 * Creates a new DFS link or adds a new target to an existing link
 *
 * Optional verification of link target existence is not implemented.
 *
 * From the spec:
 * If DFS_RESTORE_VOLUME is not specified on the Flags parameter,
 * the server MAY choose to verify whether the link target exists.
 * If DFS_RESTORE_VOLUME is specified, the server MUST NOT perform
 * this test. If it performs the test and the link target does not
 * exist, the server MUST fail the call with NERR_NetNameNotFound.
 *
 */
uint32_t
dfs_link_add(const char *path, const char *server, const char *share,
    const char *cmnt, uint32_t flags, boolean_t *newlink, uint32_t ns_type)
{
    dfs_info_t info;
    dfs_target_t *t;
    int ntargets;
    uint32_t status;
    uint32_t stat;

    *newlink = B_FALSE;

    if ((status = dfs_link_stat(path, &stat)) != ERROR_SUCCESS)
        return (status);

    switch (stat) {
    case DFS_STAT_NOTFOUND:
    case DFS_STAT_ISREPARSE:
        /* Create a new DFS link */

        status = dfs_link_getinfo(NULL, &info, DFS_INFO_LEVEL_ALL,
            ns_type);
        if (status != ERROR_SUCCESS)
            return (status);

        (void) strlcpy(info.i_comment, (cmnt) ? cmnt : "",
            sizeof (info.i_comment));
        *newlink = B_TRUE;
        break;

    case DFS_STAT_ISDFS:
    case DFS_STAT_ISFEDFS:
        /*
         * A reparse point can not contain both DFS and
         * FEDFS referrals
         */
        if ((stat == DFS_STAT_ISDFS && ns_type == SMB_NS_FEDFS) ||
            (stat == DFS_STAT_ISFEDFS && ns_type == SMB_NS_DFS))
            return (ERROR_FILE_EXISTS);

        /*
         * Add a target to an existing link only
         * if DFS_ADD_VOLUME flag is not specified.
         * The comment MUST be ignored when
         * adding a target to an existing link.
         */

        if (flags & DFS_ADD_VOLUME)
            return (ERROR_FILE_EXISTS);

        status = dfs_link_getinfo(path, &info, DFS_INFO_LEVEL_ALL,
            ns_type);
        if (status != ERROR_SUCCESS)
            return (status);

        break;

    case DFS_STAT_NOTLINK:
        /* specified path points to a non-reparse object */
        return (ERROR_FILE_EXISTS);

    default:
        return (ERROR_INTERNAL_ERROR);
    }

    /* checks to see if the target already exists */
    ntargets = info.i_ntargets;
    if (dfs_target_find(info.i_targets, ntargets, server, share) != -1) {
        dfs_info_free(&info);
        return (ERROR_FILE_EXISTS);
    }

    /* add the new target */
    t = realloc(info.i_targets, (ntargets + 1) * sizeof (dfs_target_t));
    if (t == NULL) {
        dfs_info_free(&info);
        return (ERROR_NOT_ENOUGH_MEMORY);
    }

    info.i_targets = t;
    dfs_target_init(&info.i_targets[ntargets], server, share,
        DFS_STORAGE_STATE_ONLINE);
    info.i_ntargets++;

    status = dfs_link_commit(path, &info, ns_type);

    dfs_info_free(&info);
    return (status);
}

/*
 * Removes a link or a link target from a DFS namespace. A link can be
 * removed regardless of the number of targets associated with it.
 *
 * 'server' and 'share' parameters specify a target, so if they are NULL
 * it means the link should be removed, otherwise the specified target
 * is removed if found.
 */
uint32_t
dfs_link_remove(const char *path, const char *server, const char *share,
    uint32_t ns_type)
{
    dfs_info_t info;
    uint32_t status, stat;
    int rc, idx;

    assert(dfs_isvalid_nstype(ns_type));

    if ((status = dfs_link_stat(path, &stat)) != ERROR_SUCCESS)
        return (status);

    if ((ns_type == SMB_NS_DFS && stat != DFS_STAT_ISDFS) ||
        (ns_type == SMB_NS_FEDFS && stat != DFS_STAT_ISFEDFS))
        return (ERROR_NOT_FOUND);

    if (server == NULL && share == NULL) {
        /* remove the link */
        if (smb_reparse_svcdel(path, dfs_svc_name(ns_type)) != 0)
            return (ERROR_INTERNAL_ERROR);

        return (ERROR_SUCCESS);
    }

    /* remove the specified target in the link */

    status = dfs_link_getinfo(path, &info, DFS_INFO_LEVEL_ALL, ns_type);
    if (status != ERROR_SUCCESS)
        return (status);

    /* checks to see if the target exists */
    idx = dfs_target_find(info.i_targets, info.i_ntargets, server, share);
    if (idx != -1) {
        bcopy(&info.i_targets[idx + 1], &info.i_targets[idx],
            (info.i_ntargets - idx - 1) * sizeof (dfs_target_t));
        info.i_ntargets--;
    } else {
        dfs_info_free(&info);
        return (ERROR_FILE_NOT_FOUND);
    }

    if (info.i_ntargets == 0) {
        /* if last target, then remove the link */
        rc = smb_reparse_svcdel(path, dfs_svc_name(ns_type));
        status = (rc == 0) ? ERROR_SUCCESS : ERROR_INTERNAL_ERROR;
    } else {
        status = dfs_link_commit(path, &info, ns_type);
    }

    dfs_info_free(&info);
    return (status);
}

/*
 * Sets the provided information for the specified link or link target.
 * Link is specified by 'path' and the target is specified by
 * (t_server, t_share) pair. Only information items needed for given
 * information level (infolvl) is valid in the passed DFS info structure
 * 'info'.
 */
uint32_t
dfs_link_setinfo(const char *path, dfs_info_t *info, uint32_t infolvl,
    uint32_t ns_type)
{
    dfs_info_t curinfo;
    uint32_t status;

    status = dfs_link_getinfo(path, &curinfo, DFS_INFO_LEVEL_ALL, ns_type);
    if (status != ERROR_SUCCESS)
        return (status);

    status = dfs_modinfo(DFS_OBJECT_LINK, &curinfo, info, infolvl);
    if (status == ERROR_SUCCESS)
        status = dfs_link_commit(path, &curinfo, ns_type);

    dfs_info_free(&curinfo);
    return (status);
}

/*
 * Gets the DFS link info.
 *
 * If path is NULL, it just does some initialization.
 *
 * Info level (1) only needs the UNC path which is not
 * stored, it is constructed so the function will return
 * without accessing the backend storage.
 */
uint32_t
dfs_link_getinfo(const char *path, dfs_info_t *info, uint32_t infolvl,
    uint32_t ns_type)
{
    uint32_t status;
    uuid_t uuid;
    int rc;

    bzero(info, sizeof (dfs_info_t));
    info->i_type = DFS_OBJECT_LINK;

    if (path == NULL) {
        info->i_state = DFS_VOLUME_STATE_OK;
        info->i_timeout = DFS_LINK_TIMEOUT;
        info->i_propflags = 0;
        uuid_generate_random(uuid);
        uuid_unparse(uuid, info->i_guid);
        return (ERROR_SUCCESS);
    }

    if (infolvl == 1)
        return (ERROR_SUCCESS);

    rc = smb_reparse_svcget(path, dfs_svc_name(ns_type), info);
    switch (rc) {
    case 0:
        status = ERROR_SUCCESS;
        break;
    case ENOENT:
    case ENOTSUP:
        status = ERROR_NOT_FOUND;
        break;
    default:
        status = ERROR_INTERNAL_ERROR;
        break;
    }

    return (status);
}

/*
 * Get the DFS data for the given root/link
 */
uint32_t
dfs_getinfo(dfs_node_t *dn, dfs_info_t *info, uint32_t infolvl,
    uint32_t ns_type)
{
    uint32_t status;

    if (dn->dn_type == DFS_OBJECT_LINK) {
        status = dfs_link_getinfo(dn->dn_fspath, info, infolvl,
            ns_type);
    } else {
        status = dfs_root_getinfo(dn->dn_fspath, info, infolvl,
            ns_type);
    }
    (void) strlcpy(info->i_uncpath, dn->dn_uncpath,
        sizeof (info->i_uncpath));

    if (status == ERROR_SUCCESS)
        dfs_info_trace("dfs_getinfo", info);

    return (status);
}

/*
 * ==================
 * Misc API (public)
 * ==================
 */

/*
 * Takes a DFS path in UNC format (dfs_path) and parse it into a dfs_path_t
 * structure.
 *
 * dfs_path_free() MUST be called to free the allocated memory in this
 * function.
 *
 * Returns:
 *
 * ERROR_INVALID_PARAMETER  path is not a valid UNC or not valid for the
 *              specified object type
 * ERROR_NOT_ENOUGH_MEMORY  not enough memory to peform the parse
 * ERROR_NOT_FOUND      namespace specified does not exist
 */
uint32_t
dfs_path_parse(dfs_path_t *path, const char *dfs_path, uint32_t path_type,
    uint32_t ns_type)
{
    char rootdir[DFS_PATH_MAX];
    smb_unc_t *unc;
    uint32_t status = ERROR_SUCCESS;
    int rc;

    bzero(path, sizeof (dfs_path_t));
    unc = &path->p_unc;

    rc = smb_unc_init(dfs_path, unc);
    switch (rc) {
    case EINVAL:
        return (ERROR_INVALID_PARAMETER);
    case ENOMEM:
        return (ERROR_NOT_ENOUGH_MEMORY);
    default:
        break;
    }

    if (dfs_ns_path(unc->unc_share, rootdir, DFS_PATH_MAX, ns_type)
        != ERROR_SUCCESS) {
        smb_unc_free(unc);
        return (ERROR_NOT_FOUND);
    }

    if (path_type == DFS_OBJECT_ANY)
        path->p_type = (unc->unc_path != NULL)
            ? DFS_OBJECT_LINK : DFS_OBJECT_ROOT;
    else
        path->p_type = path_type;

    switch (path->p_type) {
    case DFS_OBJECT_LINK:
        if ((unc->unc_path == NULL) || (*unc->unc_path == '\0'))
            status = ERROR_NOT_FOUND;
        else
            (void) snprintf(path->p_fspath, sizeof (path->p_fspath),
                "%s/%s", rootdir, unc->unc_path);
        break;

    case DFS_OBJECT_ROOT:
        if (unc->unc_path == NULL)
            (void) strlcpy(path->p_fspath, rootdir,
                sizeof (path->p_fspath));
        else
            status = ERROR_INVALID_PARAMETER;
        break;

    default:
        status = ERROR_INVALID_PARAMETER;
    }

    if (status != ERROR_SUCCESS)
        smb_unc_free(unc);

    return (status);
}

/*
 * Frees the allocated memory for p_unc field of the passed path
 */
void
dfs_path_free(dfs_path_t *path)
{
    if (path != NULL)
        smb_unc_free(&path->p_unc);
}

/*
 * Free the allocated memory for targets in the given info
 * structure
 */
void
dfs_info_free(dfs_info_t *info)
{
    if (info)
        free(info->i_targets);
}

uint32_t
dfs_info_copy(dfs_info_t *src_info, dfs_info_t *dst_info)
{
    dfs_target_t *src_tgt, *dst_tgt;
    int i;

    *dst_info = *src_info;

    if (src_info->i_ntargets == 0) {
        dst_info->i_ntargets = 0;
        dst_info->i_targets = NULL;
        return (ERROR_SUCCESS);
    }

    dst_info->i_targets = calloc(src_info->i_ntargets,
        sizeof (dfs_target_t));
    if (dst_info->i_targets == NULL)
        return (ERROR_NOT_ENOUGH_MEMORY);

    dst_tgt = dst_info->i_targets;
    src_tgt = src_info->i_targets;
    for (i = 0; i < src_info->i_ntargets; i++)
        *dst_tgt++ = *src_tgt++;

    return (ERROR_SUCCESS);
}

/*
 * Trace the given DFS info structure
 */
void
dfs_info_trace(const char *msg, dfs_info_t *info)
{
    dfs_target_t *t;
    int i;

    smb_tracef("%s", msg);
    if (info == NULL)
        return;

    smb_tracef("UNC\t%s", info->i_uncpath);
    smb_tracef("comment\t%s", info->i_comment);
    smb_tracef("GUID\t%s", info->i_guid);
    smb_tracef("state\t%X", info->i_state);
    smb_tracef("timeout\t%d", info->i_timeout);
    smb_tracef("props\t%X", info->i_propflags);
    smb_tracef("# targets\t%X", info->i_ntargets);

    if (info->i_targets == NULL)
        return;

    for (i = 0, t = info->i_targets; i < info->i_ntargets; i++, t++) {
        smb_tracef("[%d] \\\\%s\\%s", i, t->t_server, t->t_share);
        smb_tracef("[%d] state\t%X", i, t->t_state);
        smb_tracef("[%d] priority\t%d:%d", i, t->t_priority.p_class,
            t->t_priority.p_rank);
    }
}

/*
 * Removes DFS links and empty directories.
 *
 */
static void
dfs_ns_cleanup(const char *dir, uint32_t ns_type)
{
    char fspath[DFS_PATH_MAX];
    char *fname;
    DIR *dirp;
    struct dirent *dp;
    uint32_t stat;

    if ((dirp = opendir(dir)) == NULL)
        return;

    while ((dp = readdir(dirp)) != NULL) {
        fname = dp->d_name;

        if (strcmp(fname, ".") == 0 ||
            strcmp(fname, "..") == 0) {
            continue;
        }

        (void) snprintf(fspath, DFS_PATH_MAX, "%s/%s", dir, fname);

        if (dfs_path_isdir(fspath)) {
            dfs_ns_cleanup(fspath, ns_type);
            (void) rmdir(fspath);
            continue;
        }

        if (dfs_link_stat(fspath, &stat) != ERROR_SUCCESS)
            continue;

        if ((stat == DFS_STAT_ISDFS && ns_type == SMB_NS_DFS) ||
            (stat == DFS_STAT_ISFEDFS && ns_type == SMB_NS_FEDFS))
            (void) dfs_link_remove(fspath, NULL, NULL, ns_type);
    }

    (void) closedir(dirp);
}

static int
dfs_root_add(const char *rootdir, dfs_info_t *info)
{
    uint32_t status = ERROR_INTERNAL_ERROR;
    int xfd;

    (void) rw_wrlock(&dfs_root_rwl);
    if ((xfd = dfs_root_xopen(rootdir, O_CREAT | O_TRUNC | O_RDWR)) > 0) {
        status = dfs_root_xwrite(xfd, info);
        dfs_root_xclose(xfd);
    }
    (void) rw_unlock(&dfs_root_rwl);

    return (status);
}

/*
 * Deletes the specified root information
 */
static uint32_t
dfs_root_remove(const char *rootdir)
{
    int attrdirfd;
    int err = 0;

    (void) rw_wrlock(&dfs_root_rwl);

    if ((attrdirfd = attropen(rootdir, ".", O_RDONLY)) > 0) {
        if (unlinkat(attrdirfd, DFS_ROOT_XATTR, 0) == -1) {
            if (errno != ENOENT)
                err = errno;
        }
        (void) close(attrdirfd);
    } else {
        err = errno;
    }

    (void) rw_unlock(&dfs_root_rwl);

    if (err != 0) {
        syslog(LOG_DEBUG, "dfs: failed to remove root info %s (%d)",
            rootdir, err);
        return (ERROR_INTERNAL_ERROR);
    }

    return (ERROR_SUCCESS);
}

/*
 * Opens DFS root directory's extended attribute with the given mode.
 */
static int
dfs_root_xopen(const char *rootdir, int oflag)
{
    int dfd;
    int xfd = -1;
    int err = 0;

    if ((dfd = open(rootdir, O_RDONLY)) > 0) {
        xfd = openat(dfd, DFS_ROOT_XATTR, oflag | O_XATTR, 0600);
        if (xfd == -1)
            err = errno;
        (void) close(dfd);
    } else {
        err = errno;
    }

    if (err != 0) {
        syslog(LOG_DEBUG, "dfs: failed to open root directory %s (%d)",
            rootdir, err);
    }

    return (xfd);
}

/*
 * Closes given extended attribute file descriptor
 */
static void
dfs_root_xclose(int xfd)
{
    (void) close(xfd);
}

/*
 * Writes the given DFS data in the DFS root directory's
 * extended attribute specified with xfd file descriptor.
 */
static uint32_t
dfs_root_xwrite(int xfd, dfs_info_t *info)
{
    size_t nbytes;
    char *buf = NULL;
    size_t buflen;
    uint32_t status;

    if ((status = dfs_root_encode(info, &buf, &buflen)) != ERROR_SUCCESS)
        return (status);

    (void) lseek(xfd, 0, SEEK_SET);
    nbytes = write(xfd, buf, buflen);
    free(buf);

    return ((nbytes == buflen) ? ERROR_SUCCESS : ERROR_INTERNAL_ERROR);
}

/*
 * Reads DFS root information from its directory extended attribute
 * and parse it into given dfs_info_t structure
 */
static uint32_t
dfs_root_xread(int xfd, dfs_info_t *info, uint32_t infolvl)
{
    struct stat statbuf;
    uint32_t status;
    char *buf;

    if (fstat(xfd, &statbuf) != 0)
        return (ERROR_INTERNAL_ERROR);

    if ((buf = malloc(statbuf.st_size)) == NULL)
        return (ERROR_NOT_ENOUGH_MEMORY);

    if (read(xfd, buf, statbuf.st_size) == statbuf.st_size)
        status = dfs_root_decode(info, buf, statbuf.st_size, infolvl);
    else
        status = ERROR_INTERNAL_ERROR;

    free(buf);
    return (status);
}

/*
 * Encodes (packs) DFS information in 'info' into a flat
 * buffer in a name-value format. This function allocates a
 * buffer with appropriate size to contain all the information
 * so the caller MUST free the allocated memory by calling free().
 */
static uint32_t
dfs_root_encode(dfs_info_t *info, char **buf, size_t *bufsz)
{
    dfs_target_t *t;
    nvlist_t *nvl;
    int rc;

    if (nvlist_alloc(&nvl, NV_UNIQUE_NAME, 0) != 0)
        return (ERROR_NOT_ENOUGH_MEMORY);

    rc = nvlist_add_string(nvl, DFS_ROOT_PROP_SVCTYPE,
        dfs_svc_name(info->i_ns_type));
    rc |= nvlist_add_string(nvl, DFS_ROOT_PROP_CMNT, info->i_comment);
    rc |= nvlist_add_string(nvl, DFS_ROOT_PROP_GUID, info->i_guid);
    rc |= nvlist_add_uint32(nvl, DFS_ROOT_PROP_STATE, info->i_state);
    rc |= nvlist_add_uint32(nvl, DFS_ROOT_PROP_TTL, info->i_timeout);
    rc |= nvlist_add_uint32(nvl, DFS_ROOT_PROP_FLAGS, info->i_propflags);
    t = info->i_targets;
    rc |= nvlist_add_string(nvl, DFS_ROOT_PROP_SERVER, t->t_server);
    rc |= nvlist_add_string(nvl, DFS_ROOT_PROP_SHARE, t->t_share);
    rc |= nvlist_add_uint32(nvl, DFS_ROOT_PROP_TSTATE, t->t_state);
    rc |= nvlist_add_uint32(nvl, DFS_ROOT_PROP_PRI_CLASS,
        t->t_priority.p_class);
    rc |= nvlist_add_uint16(nvl, DFS_ROOT_PROP_PRI_RANK,
        t->t_priority.p_rank);

    if (rc == 0)
        rc = nvlist_pack(nvl, buf, bufsz, NV_ENCODE_NATIVE, 0);

    nvlist_free(nvl);

    return ((rc == 0) ? ERROR_SUCCESS : ERROR_INTERNAL_ERROR);
}

/*
 * Decodes (unpack) provided buffer which contains a list of name-value
 * pairs into given dfs_info_t structure
 */
static uint32_t
dfs_root_decode(dfs_info_t *info, char *buf, size_t bufsz, uint32_t infolvl)
{
    nvlist_t *nvl;
    char *cmnt, *svctype, *guid;
    char *t_server, *t_share;
    uint32_t t_state;
    uint32_t t_priority_class;
    uint16_t t_priority_rank;
    boolean_t decode_priority = B_FALSE;
    int rc;

    if (nvlist_unpack(buf, bufsz, &nvl, 0) != 0)
        return (ERROR_INTERNAL_ERROR);

    rc = nvlist_lookup_string(nvl, DFS_ROOT_PROP_SVCTYPE, &svctype);
    if (rc == ENOENT) {
        /*
         * If not defined, use SMB-DFS
         */
        svctype = DFS_REPARSE_SVCTYPE;
        rc = 0;
    }
    rc |= nvlist_lookup_string(nvl, DFS_ROOT_PROP_CMNT, &cmnt);
    rc |= nvlist_lookup_string(nvl, DFS_ROOT_PROP_GUID, &guid);
    rc |= nvlist_lookup_uint32(nvl, DFS_ROOT_PROP_STATE, &info->i_state);
    rc |= nvlist_lookup_uint32(nvl, DFS_ROOT_PROP_TTL, &info->i_timeout);
    rc |= nvlist_lookup_uint32(nvl, DFS_ROOT_PROP_FLAGS,
        &info->i_propflags);

    if (rc != 0) {
        nvlist_free(nvl);
        return (ERROR_INTERNAL_ERROR);
    }

    info->i_ns_type = dfs_ns_type(svctype);
    (void) strlcpy(info->i_comment, (cmnt) ? cmnt : "",
        sizeof (info->i_comment));
    (void) strlcpy(info->i_guid, (guid) ? guid : "", sizeof (info->i_guid));

    info->i_targets = NULL;
    info->i_ntargets = 1;

    switch (infolvl) {
    case DFS_INFO_LEVEL_ALL:
    case DFS_INFO_LEVEL_3:
    case DFS_INFO_LEVEL_4:
        /* need target information */
        break;
    case DFS_INFO_LEVEL_6:
    case DFS_INFO_LEVEL_9:
        /* need target and priority information */
        decode_priority = B_TRUE;
        break;
    default:
        nvlist_free(nvl);
        return (ERROR_SUCCESS);
    }

    info->i_targets = malloc(sizeof (dfs_target_t));
    if (info->i_targets == NULL) {
        nvlist_free(nvl);
        return (ERROR_NOT_ENOUGH_MEMORY);
    }

    rc = nvlist_lookup_string(nvl, DFS_ROOT_PROP_SERVER, &t_server);
    rc |= nvlist_lookup_string(nvl, DFS_ROOT_PROP_SHARE, &t_share);
    rc |= nvlist_lookup_uint32(nvl, DFS_ROOT_PROP_TSTATE, &t_state);
    if (rc != 0) {
        nvlist_free(nvl);
        free(info->i_targets);
        return (ERROR_INTERNAL_ERROR);
    }
    dfs_target_init(info->i_targets, t_server, t_share, t_state);

    if (decode_priority) {
        rc = nvlist_lookup_uint32(nvl, DFS_ROOT_PROP_PRI_CLASS,
            &t_priority_class);
        if (rc == 0)
            rc = nvlist_lookup_uint16(nvl, DFS_ROOT_PROP_PRI_RANK,
                &t_priority_rank);

        if (rc != 0 && rc != ENOENT) {
            nvlist_free(nvl);
            free(info->i_targets);
            return (ERROR_INTERNAL_ERROR);
        } else if (rc == 0) {
            info->i_targets->t_priority.p_class = t_priority_class;
            info->i_targets->t_priority.p_rank = t_priority_rank;
        }
    }

    nvlist_free(nvl);
    return (ERROR_SUCCESS);
}

/*
 * Determines if the passed state is valid for a DFS root
 *
 * This is based on test results against Win2003 and in some cases
 * does not match [MS-DFSNM] spec.
 */
static uint32_t
dfs_root_isvalidstate(uint32_t state)
{
    switch (state) {
    case DFS_VOLUME_STATE_OK:
    case DFS_VOLUME_STATE_RESYNCHRONIZE:
        return (ERROR_SUCCESS);

    case DFS_VOLUME_STATE_INCONSISTENT:
    case DFS_VOLUME_STATE_FORCE_SYNC:
        return (ERROR_INVALID_PARAMETER);

    case DFS_VOLUME_STATE_OFFLINE:
    case DFS_VOLUME_STATE_ONLINE:
    case DFS_VOLUME_STATE_STANDBY:
        return (ERROR_NOT_SUPPORTED);
    default:
        break;
    }

    return (ERROR_INVALID_PARAMETER);
}

/*
 * Stores given information for the specified link
 *
 */
static uint32_t
dfs_link_commit(const char *path, dfs_info_t *info, uint32_t ns_type)
{
    uint32_t status;
    int rc;

    rc = smb_reparse_svcadd(path, dfs_svc_name(ns_type), info);
    if (rc != 0) {
        switch (rc) {
        case ENOTSUP:
            status = ERROR_NOT_FOUND;
            break;
        case ENOMEM:
            status = ERROR_NOT_ENOUGH_MEMORY;
            break;
        case EINVAL:
            status = ERROR_INVALID_NAME;
            break;
        default:
            status = ERROR_INTERNAL_ERROR;
            break;
        }
    } else {
        status = ERROR_SUCCESS;
    }

    return (status);
}

/*
 * Determines if the passed state is valid for a link
 */
static boolean_t
dfs_link_isvalidstate(uint32_t state)
{
    return (state == DFS_VOLUME_STATE_OK ||
        state == DFS_VOLUME_STATE_OFFLINE ||
        state == DFS_VOLUME_STATE_ONLINE);
}

/*
 * Initializes the given target structure (t) with provided information.
 */
static void
dfs_target_init(dfs_target_t *t, const char *srv, const char *share,
    uint32_t state)
{
    (void) strlcpy(t->t_server, (srv) ? srv : "", sizeof (t->t_server));
    (void) strlcpy(t->t_share, (share) ? share : "", sizeof (t->t_share));
    t->t_state = state;
    t->t_priority.p_class = DfsSiteCostNormalPriorityClass;
    t->t_priority.p_rank = 0;
}

/*
 * Lookup the specified target (server, share) in the given
 * target list (targets). If there is a match its index is
 * returned, otherwise -1 will be returned.
 */
static int
dfs_target_find(dfs_target_t *targets, uint32_t ntargets,
    const char *server, const char *share)
{
    dfs_target_t *t;
    int i;

    for (i = 0, t = targets; i < ntargets; i++, t++) {
        if ((smb_strcasecmp(t->t_server, server, 0) == 0) &&
            (smb_strcasecmp(t->t_share, share, 0) == 0))
            return (i);
    }

    return (-1);
}

/*
 * Determines if the passed state is valid for a link/root target
 */
static boolean_t
dfs_target_isvalidstate(uint32_t state)
{
    return (state == DFS_STORAGE_STATE_ONLINE ||
        state == DFS_STORAGE_STATE_OFFLINE);
}

/*
 * Compare function used by smb_avl_t
 */
static int
dfs_node_cmp(const void *p1, const void *p2)
{
    dfs_node_t *dn1 = (dfs_node_t *)p1;
    dfs_node_t *dn2 = (dfs_node_t *)p2;
    int rc;

    assert(dn1);
    assert(dn2);

    rc = smb_strcasecmp(dn1->dn_uncpath, dn2->dn_uncpath, 0);

    if (rc < 0)
        return (-1);

    if (rc > 0)
        return (1);

    return (0);
}

static dfs_node_t *
dfs_node_create(const char *uncpath, const char *fspath, uint32_t type)
{
    dfs_node_t *dn;

    if ((dn = calloc(1, sizeof (dfs_node_t))) == NULL)
        return (NULL);

    (void) strlcpy(dn->dn_uncpath, uncpath, sizeof (dn->dn_uncpath));
    (void) strlcpy(dn->dn_fspath, fspath, sizeof (dn->dn_fspath));
    dn->dn_type = type;

    return (dn);
}

static void
dfs_node_destroy(void *p)
{
    free(p);
}

/*
 * starting from DFS root directory, scans the tree for DFS links
 * and adds them to the cache.
 *
 * The caller must be holding the namespace lock (dfsns.ns_lock) for writing.
 */
static void
dfs_ns_populate_cache(const char *unc_prefix, const char *dir)
{
    dfs_node_t *dn;
    char fspath[DFS_PATH_MAX];
    char uncpath[DFS_PATH_MAX];
    char *fname;
    DIR *dirp;
    struct dirent *dp;
    uint32_t stat;

    if (dfsns.ns_cache == NULL)
        return;

    if ((dirp = opendir(dir)) == NULL)
        return;

    while ((dp = readdir(dirp)) != NULL) {
        fname = dp->d_name;

        if (strcmp(fname, ".") == 0 ||
            strcmp(fname, "..") == 0) {
            continue;
        }

        (void) snprintf(fspath, DFS_PATH_MAX, "%s/%s", dir, fname);
        (void) snprintf(uncpath, DFS_PATH_MAX, "%s\\%s", unc_prefix,
            fname);

        if (dfs_path_isdir(fspath)) {
            dfs_ns_populate_cache(uncpath, fspath);
        } else if (dfs_link_stat(fspath, &stat) == ERROR_SUCCESS) {
            if (DFS_STAT_ISSMB(stat)) {
                dn = dfs_node_create(uncpath, fspath,
                    DFS_OBJECT_LINK);
                if (dn != NULL) {
                    if (smb_avl_add(dfsns.ns_cache, dn)
                        != 0)
                        dfs_node_destroy(dn);
                }
            }
        }
    }

    (void) closedir(dirp);
}

/*
 * Creates a cache for the given namespace, traverse
 * the file system starting from the given path looking
 * for all the links and load their information into the
 * cache.
 *
 * The caller must be holding the namespace lock (dfsns.ns_lock) for writing.
 */
static void
dfs_ns_load(const char *name, const char *path)
{
    dfs_node_t *dn;
    char uncpath[DFS_PATH_MAX];

    (void) smb_config_setnum(SMB_CI_DFS_STDROOT_NUM, 1);

    /*
     * only cache referrals for DFS namespaces
     */
    if (dfsns.ns_type != SMB_NS_DFS)
        return;

    dfsns.ns_cache = smb_avl_create(sizeof (dfs_node_t),
        offsetof(dfs_node_t, dn_hook), &dfs_node_ops);

    if (dfsns.ns_cache != NULL) {
        (void) snprintf(uncpath, DFS_PATH_MAX, "\\\\%s\\%s", dfs_nbname,
            name);
        dn = dfs_node_create(uncpath, path, DFS_OBJECT_ROOT);
        if (dn != NULL) {
            if (smb_avl_add(dfsns.ns_cache, dn) != 0)
                dfs_node_destroy(dn);
        }
        dfs_ns_populate_cache(uncpath, path);
    }
}

/*
 * If this namespace hasn't been cached then return
 * without flushing the cache; otherwise flush and
 * destroy the cache.
 *
 * The caller must be holding the namespace lock
 * (dfsns.ns_lock) for writing.
 */
static void
dfs_ns_unload(const char *name)
{
    NOTE(ARGUNUSED(name))

    (void) smb_config_setnum(SMB_CI_DFS_STDROOT_NUM, 0);

    if (dfsns.ns_cache != NULL) {
        smb_avl_flush(dfsns.ns_cache);
        smb_avl_destroy(dfsns.ns_cache);
        dfsns.ns_cache = NULL;
    }
}

/*
 * Determines whether the given path is a directory.
 */
static boolean_t
dfs_path_isdir(const char *path)
{
    struct stat statbuf;

    if (lstat(path, &statbuf) != 0)
        return (B_FALSE);

    return ((statbuf.st_mode & S_IFMT) == S_IFDIR);
}

/*
 * Creates intermediate directories of a link from the root share path.
 *
 * TODO: directories should be created by smbsrv to get Windows compatible
 * ACL inheritance.
 */
static void
dfs_path_create(const char *path)
{
    char dirpath[DFS_PATH_MAX];
    mode_t mode;
    char *p;

    (void) strlcpy(dirpath, path, DFS_PATH_MAX);

    /* drop the link itself from the path */
    if ((p = strrchr(dirpath, '/')) != NULL) {
        *p = '\0';
        mode = umask(0);
        (void) mkdirp(dirpath, 0777);
        (void) umask(mode);
    }
}

/*
 * Removes empty directories
 */
static void
dfs_path_remove(smb_unc_t *unc, uint32_t ns_type)
{
    char rootdir[DFS_PATH_MAX];
    char relpath[DFS_PATH_MAX];
    char dir[DFS_PATH_MAX];
    uint32_t status;
    char *p;

    status = dfs_ns_path(unc->unc_share, rootdir, DFS_PATH_MAX, ns_type);
    if ((status == ERROR_SUCCESS) && (chdir(rootdir) == 0)) {
        (void) strlcpy(relpath, unc->unc_path, DFS_PATH_MAX);
        /* drop the link itself from the path */
        if ((p = strrchr(relpath, '/')) != NULL) {
            *p = '\0';
            (void) rmdirp(relpath, dir);
        }
    }
}


/*
 * Validates the given state based on the object type (root/link), info
 * level, and whether it is the object's state or its target's state
 */
static uint32_t
dfs_isvalidstate(uint32_t state, uint32_t type, boolean_t target,
    uint32_t infolvl)
{
    uint32_t status = ERROR_SUCCESS;

    switch (infolvl) {
    case DFS_INFO_LEVEL_101:
        if (type == DFS_OBJECT_ROOT) {
            if (!target)
                return (dfs_root_isvalidstate(state));

            if (!dfs_target_isvalidstate(state))
                status = ERROR_INVALID_PARAMETER;
            else if (state == DFS_STORAGE_STATE_OFFLINE)
                status = ERROR_NOT_SUPPORTED;
        } else {
            if (!target) {
                if (!dfs_link_isvalidstate(state))
                    status = ERROR_INVALID_PARAMETER;
            } else {
                if (!dfs_target_isvalidstate(state))
                    status = ERROR_INVALID_PARAMETER;
            }
        }
        break;

    case DFS_INFO_LEVEL_105:
        if (state == 0)
            return (ERROR_SUCCESS);

        if (type == DFS_OBJECT_ROOT) {
            switch (state) {
            case DFS_VOLUME_STATE_OK:
            case DFS_VOLUME_STATE_OFFLINE:
            case DFS_VOLUME_STATE_ONLINE:
            case DFS_VOLUME_STATE_RESYNCHRONIZE:
            case DFS_VOLUME_STATE_STANDBY:
                status = ERROR_NOT_SUPPORTED;
                break;

            default:
                status = ERROR_INVALID_PARAMETER;
            }
        } else {
            switch (state) {
            case DFS_VOLUME_STATE_OK:
            case DFS_VOLUME_STATE_OFFLINE:
            case DFS_VOLUME_STATE_ONLINE:
                break;

            case DFS_VOLUME_STATE_RESYNCHRONIZE:
            case DFS_VOLUME_STATE_STANDBY:
                status = ERROR_NOT_SUPPORTED;
                break;

            default:
                status = ERROR_INVALID_PARAMETER;
            }
        }
        break;

    default:
        status = ERROR_INVALID_LEVEL;
    }

    return (status);
}

/*
 * Validates the given property flag mask based on the object
 * type (root/link) and namespace flavor.
 */
static uint32_t
dfs_isvalidpropflagmask(uint32_t propflag_mask, uint32_t type,
    uint32_t flavor)
{
    uint32_t flgs_not_supported;

    flgs_not_supported = DFS_PROPERTY_FLAG_ROOT_SCALABILITY
        | DFS_PROPERTY_FLAG_CLUSTER_ENABLED
        | DFS_PROPERTY_FLAG_ABDE;

    if (flavor == DFS_VOLUME_FLAVOR_STANDALONE) {
        if (type == DFS_OBJECT_LINK)
            flgs_not_supported |= DFS_PROPERTY_FLAG_SITE_COSTING;
        if (propflag_mask & flgs_not_supported)
            return (ERROR_NOT_SUPPORTED);
    }

    return (ERROR_SUCCESS);
}

/*
 * Based on the specified information level (infolvl) copy parts of the
 * information provided through newinfo into the existing information
 * (info) for the given object.
 */
static uint32_t
dfs_modinfo(uint32_t type, dfs_info_t *info, dfs_info_t *newinfo,
    uint32_t infolvl)
{
    boolean_t target_op = B_FALSE;
    uint32_t status = ERROR_SUCCESS;
    uint32_t state;
    int target_idx;

    if (newinfo->i_targets != NULL) {
        target_idx = dfs_target_find(info->i_targets, info->i_ntargets,
            newinfo->i_targets->t_server, newinfo->i_targets->t_share);
        if (target_idx == -1)
            return (ERROR_FILE_NOT_FOUND);
        target_op = B_TRUE;
    }

    switch (infolvl) {
    case DFS_INFO_LEVEL_100:
        (void) strlcpy(info->i_comment, newinfo->i_comment,
            sizeof (newinfo->i_comment));
        break;

    case DFS_INFO_LEVEL_101:
        state = (target_op)
            ? newinfo->i_targets->t_state : newinfo->i_state;
        status = dfs_isvalidstate(state, type, target_op, 101);
        if (status != ERROR_SUCCESS)
            return (status);

        if (!target_op) {
            /*
             * states specified by this mask should not be stored
             */
            if (state & DFS_VOLUME_STATES_SRV_OPS)
                return (ERROR_SUCCESS);

            info->i_state = state;
        } else {
            info->i_targets[target_idx].t_state = state;
        }
        break;

    case DFS_INFO_LEVEL_102:
        info->i_timeout = newinfo->i_timeout;
        break;

    case DFS_INFO_LEVEL_103:
        info->i_propflags = newinfo->i_propflags;
        break;

    case DFS_INFO_LEVEL_104:
        info->i_targets[target_idx].t_priority =
            newinfo->i_targets->t_priority;
        break;

    case DFS_INFO_LEVEL_105:
        status = dfs_isvalidstate(newinfo->i_state, type, B_FALSE, 105);
        if (status != ERROR_SUCCESS)
            return (status);

        status = dfs_isvalidpropflagmask(newinfo->i_propflag_mask, type,
            newinfo->i_flavor);
        if (status != ERROR_SUCCESS)
            return (status);

        (void) strlcpy(info->i_comment, newinfo->i_comment,
            sizeof (newinfo->i_comment));
        if (newinfo->i_state != 0)
            info->i_state = newinfo->i_state;
        info->i_timeout = newinfo->i_timeout;
        info->i_propflags = newinfo->i_propflags;
        break;

    default:
        status = ERROR_INVALID_LEVEL;
    }

    return (status);
}

static boolean_t
dfs_isvalid_nstype(uint32_t ns_type)
{
    int i;

    for (i = 0; i < DFS_NS_NUM; ++i) {
        if (dfs_ns_info[i].ns_type == ns_type)
            return (B_TRUE);
    }

    return (B_FALSE);
}

/*
 * return service type string from namespace type
 */
static const char *
dfs_svc_name(uint32_t ns_type)
{
    int i;

    for (i = 0; i < DFS_NS_NUM; ++i) {
        if (dfs_ns_info[i].ns_type == ns_type)
            return (dfs_ns_info[i].svc_name);
    }

    return (DFS_UNKNOWN_SVCTYPE);
}

/*
 * return namespace type from service type string
 */
static uint32_t
dfs_ns_type(const char *svc_name)
{
    int i;

    for (i = 0; i < DFS_NS_NUM; ++i) {
        if (strcasecmp(svc_name, dfs_ns_info[i].svc_name) == 0)
            return (dfs_ns_info[i].ns_type);
    }

    /* default to SMB-DFS */
    return (SMB_NS_DFS);
}