/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2017-2022 Tintri by DDN, Inc. All rights reserved.
 * Copyright 2021-2024 RackTop Systems, Inc.
 */

/*
 * SMB2 Durable Handle support
 */

#include <sys/types.h>
#include <sys/cmn_err.h>
#include <sys/fcntl.h>
#include <sys/nbmlock.h>
#include <sys/sid.h>
#include <smbsrv/string.h>
#include <smbsrv/smb_kproto.h>
#include <smbsrv/smb_fsops.h>
#include <smbsrv/smbinfo.h>
#include <smbsrv/smb2_kproto.h>

/* Windows default values from [MS-SMB2] */
/*
 * (times in seconds)
 * resilient:
 * MaxTimeout = 300 (win7+)
 * if timeout > MaxTimeout, ERROR
 * if timeout != 0, timeout = req.timeout
 * if timeout == 0, timeout = (infinity) (Win7/w2k8r2)
 * if timeout == 0, timeout = 120 (Win8+)
 * v2:
 * if timeout != 0, timeout = MIN(timeout, 300) (spec)
 * if timeout != 0, timeout = timeout (win8/2k12)
 * if timeout == 0, timeout = Share.CATimeout. \
 *      if Share.CATimeout == 0, timeout = 60 (win8/w2k12)
 * if timeout == 0, timeout = 180 (win8.1/w2k12r2)
 * open.timeout = 60 (win8/w2k12r2) (i.e. we ignore the request)
 * v1:
 * open.timeout = 16 minutes
 */

uint32_t smb2_dh_def_timeout = 60 * MILLISEC;   /* mSec. */
uint32_t smb2_dh_max_timeout = 300 * MILLISEC;  /* mSec. */

uint32_t smb2_res_def_timeout = 120 * MILLISEC; /* mSec. */
uint32_t smb2_res_max_timeout = 300 * MILLISEC; /* mSec. */

uint32_t smb2_persist_timeout = 300 * MILLISEC; /* mSec. */

/*
 * Escape hatch in case persistent handles on directories cause problems.
 * We don't have directory leases, so there's not really much point in
 * persistence for directory handles, but Hyper-V wants them.
 */
int smb2_dh_allow_dir = 1;

/*
 * Max. size of the file used to store a CA handle.
 * Don't adjust this while the server is running.
 */
static uint32_t smb2_dh_max_cah_size = 64 * 1024;
static uint32_t smb2_ca_info_version = 1;

/*
 * Want this to have invariant layout on disk, where the
 * last two uint32_t values are stored as a uint64_t
 */
struct nvlk {
        uint64_t lk_start;
        uint64_t lk_len;
        /* (lk_pid << 32) | lk_type */
#ifdef  _BIG_ENDIAN
        uint32_t lk_pid, lk_type;
#else
        uint32_t lk_type, lk_pid;
#endif
};

static void smb2_dh_import_share(void *);
static smb_ofile_t *smb2_dh_import_handle(smb_request_t *, smb_node_t *,
    char *, uint64_t);
static int smb2_dh_read_nvlist(smb_request_t *, smb_node_t *,
    char *, struct nvlist **);
static int smb2_dh_import_cred(smb_ofile_t *, char *);

#define DH_SN_SIZE 24   /* size of DH stream name buffers */
/*
 * Build the stream name used to store a CA handle.
 * i.e. ":0123456789abcdef:$CA"
 * Note: smb_fsop_create adds the SUNWsmb prefix,
 * so we compose the name without the prefix.
 */
static inline void
smb2_dh_make_stream_name(char *buf, size_t buflen, uint64_t id)
{
        ASSERT(buflen >= DH_SN_SIZE);
        (void) snprintf(buf, buflen,
            ":%016" PRIx64 ":$CA", id);
}

/*
 * smb_dh_create_allowed
 *
 * Helper for smb2_create to decide whether the open/create call should
 * allow this handle to become durable.
 *
 * For files:
 * 1. op_oplock_level == SMB2_OPLOCK_LEVEL_BATCH
 * 2. A lease is requested with handle caching
 *    - for v1, the lease must not be on a directory
 * 3. For v2, flags has "persistent" (tree is CA)
 *    (when tree not CA, turned off persist earlier)
 *
 * For directories, we don't do leases, but allow persistent.
 */
boolean_t
smb_dh_create_allowed(smb_request_t *sr, smb_ofile_t *of)
{
        smb_arg_open_t *op = &sr->arg.open;

        if (smb2_dh_allow_dir && smb_node_is_dir(of->f_node) &&
            (op->dh_v2_flags & SMB2_DHANDLE_FLAG_PERSISTENT) != 0)
                return (B_TRUE);

        if (smb_node_is_file(of->f_node) &&
            ((op->dh_v2_flags & SMB2_DHANDLE_FLAG_PERSISTENT) != 0 ||
            (op->op_oplock_level == SMB2_OPLOCK_LEVEL_BATCH) ||
            (op->op_oplock_level == SMB2_OPLOCK_LEVEL_LEASE &&
            (op->lease_state & OPLOCK_LEVEL_CACHE_HANDLE) != 0)))
                return (B_TRUE);

        return (B_FALSE);
}


/*
 * smb_dh_should_save
 *
 * During session tear-down, decide whether to keep a durable handle.
 *
 * There are two cases where we save durable handles:
 * 1. An SMB2 LOGOFF request was received
 * 2. An unexpected disconnect from the client
 *    Note: Specifying a PrevSessionID in session setup
 *    is considered a disconnect (we just haven't learned about it yet)
 * In every other case, we close durable handles.
 *
 * [MS-SMB2] 3.3.5.6 SMB2_LOGOFF
 * [MS-SMB2] 3.3.7.1 Handling Loss of a Connection
 *
 * If any of the following are true, preserve for reconnect:
 *
 * - Open.IsResilient is TRUE.
 *
 * - Open.OplockLevel == SMB2_OPLOCK_LEVEL_BATCH and
 *   Open.OplockState == Held, and Open.IsDurable is TRUE.
 *
 * - Open.OplockLevel == SMB2_OPLOCK_LEVEL_LEASE,
 *   Lease.LeaseState SMB2_LEASE_HANDLE_CACHING,
 *   Open.OplockState == Held, and Open.IsDurable is TRUE.
 *
 * - Open.IsPersistent is TRUE.
 *
 * We also deal with some special cases for shutdown of the
 * server, session, user, tree (in that order). Other than
 * the cases above, shutdown (or forced termination) should
 * destroy durable handles.
 */
boolean_t
smb_dh_should_save(smb_ofile_t *of)
{
        ASSERT(MUTEX_HELD(&of->f_mutex));
        ASSERT(of->dh_vers != SMB2_NOT_DURABLE);

        /* SMB service shutting down, destroy DH */
        if (of->f_server->sv_state == SMB_SERVER_STATE_STOPPING)
                return (B_FALSE);

        /*
         * SMB Session (connection) going away (server up).
         * If server initiated disconnect, destroy DH
         * If client initiated disconnect, save all DH.
         */
        if (of->f_session->s_state == SMB_SESSION_STATE_TERMINATED)
                return (B_FALSE);
        if (of->f_session->s_state == SMB_SESSION_STATE_DISCONNECTED)
                return (B_TRUE);

        /*
         * SMB User logoff, session still "up".
         * Action depends on why/how this logoff happened,
         * determined based on user->preserve_opens
         */
        if (of->f_user->u_state == SMB_USER_STATE_LOGGING_OFF) {
                switch (of->f_user->preserve_opens) {
                case SMB2_DH_PRESERVE_NONE:
                        /* Server-initiated */
                        return (B_FALSE);
                case SMB2_DH_PRESERVE_SOME:
                        /* Previous session logoff. */
                        goto preserve_some;
                case SMB2_DH_PRESERVE_ALL:
                        /* Protocol logoff request */
                        return (B_TRUE);
                }
        }

        /*
         * SMB tree disconnecting (user still logged on)
         * i.e. when kshare export forces disconnection.
         */
        if (of->f_tree->t_state == SMB_TREE_STATE_DISCONNECTING)
                return (B_FALSE);

preserve_some:
        /* preserve_opens == SMB2_DH_PRESERVE_SOME */

        switch (of->dh_vers) {
                uint32_t ol_state;

        case SMB2_RESILIENT:
                return (B_TRUE);

        case SMB2_DURABLE_V2:
                if (of->dh_persist)
                        return (B_TRUE);
                /* FALLTHROUGH */
        case SMB2_DURABLE_V1:
                /* IS durable (v1 or v2) */
                if (of->f_lease != NULL)
                        ol_state = of->f_lease->ls_state;
                else
                        ol_state = of->f_oplock.og_state;
                if ((ol_state & (OPLOCK_LEVEL_BATCH |
                    OPLOCK_LEVEL_CACHE_HANDLE)) != 0)
                        return (B_TRUE);
                /* FALLTHROUGH */
        case SMB2_NOT_DURABLE:
        default:
                break;
        }

        return (B_FALSE);
}

/*
 * Is this stream name a CA handle? i.e.
 * ":0123456789abcdef:$CA"
 */
static boolean_t
smb2_dh_match_ca_name(const char *name, uint64_t *idp)
{
        static const char suffix[] = ":$CA";
        u_longlong_t ull;
        const char *p = name;
        char *p2 = NULL;
        int len, rc;

        if (*p++ != ':')
                return (B_FALSE);

        rc = ddi_strtoull(p, &p2, 16, &ull);
        if (rc != 0 || p2 != (p + 16))
                return (B_FALSE);
        p += 16;

        len = sizeof (suffix) - 1;
        if (strncmp(p, suffix, len) != 0)
                return (B_FALSE);
        p += len;

        if (*p != '\0')
                return (B_FALSE);

        *idp = (uint64_t)ull;
        return (B_TRUE);
}

/*
 * smb2_dh_new_ca_share
 *
 * Called when a new share has ca=true.  Find or create the CA dir,
 * and start a thread to import persistent handles.
 */
int
smb2_dh_new_ca_share(smb_server_t *sv, smb_kshare_t *shr)
{
        smb_kshare_t    *shr2;
        smb_request_t   *sr;
        taskqid_t       tqid;

        ASSERT(STYPE_ISDSK(shr->shr_type));

        /*
         * Need to lookup the kshare again, to get a hold.
         * Add a function to just get the hold?
         */
        shr2 = smb_kshare_lookup(sv, shr->shr_name);
        if (shr2 != shr)
                return (EINVAL);

        sr = smb_request_alloc(sv->sv_session, 0);
        if (sr == NULL) {
                /* shutting down? */
                smb_kshare_release(sv, shr);
                return (EINTR);
        }
        sr->sr_state = SMB_REQ_STATE_SUBMITTED;

        /*
         * Mark this share as "busy importing persistent handles"
         * so we can hold off tree connect until that's done.
         * Will clear and wakeup below.
         */
        mutex_enter(&shr->shr_mutex);
        shr->shr_import_busy = sr;
        mutex_exit(&shr->shr_mutex);

        /*
         * Start a taskq job to import any CA handles.
         * The hold on the kshare is given to this job,
         * which releases it when it's done.
         */
        sr->arg.tcon.si = shr;  /* hold from above */
        tqid = taskq_dispatch(sv->sv_worker_pool,
            smb2_dh_import_share, sr, TQ_SLEEP);
        VERIFY(tqid != TASKQID_INVALID);

        return (0);
}

int smb2_dh_import_delay = 0;

static void
smb2_dh_import_share(void *arg)
{
        smb_request_t   *sr = arg;
        smb_kshare_t    *shr = sr->arg.tcon.si;
        smb_node_t      *snode;
        cred_t          *kcr = zone_kcred();
        smb_streaminfo_t *str_info = NULL;
        char            *nvl_buf = NULL;
        uint64_t        id;
        smb_node_t      *str_node;
        smb_odir_t      *od = NULL;
        smb_ofile_t     *of;
        int             rc;
        boolean_t       eof;

        sr->sr_state = SMB_REQ_STATE_ACTIVE;

        if (smb2_dh_import_delay > 0)
                delay(SEC_TO_TICK(smb2_dh_import_delay));

        /*
         * Borrow the server's "root" user.
         *
         * This takes the place of smb_session_lookup_ssnid()
         * that would happen in smb2_dispatch for a normal SR.
         * As usual, this hold is released in smb_request_free.
         */
        sr->uid_user = sr->sr_server->sv_rootuser;
        smb_user_hold_internal(sr->uid_user);
        sr->user_cr = sr->uid_user->u_cred;

        /*
         * Create a temporary tree connect
         */
        sr->tid_tree = smb_tree_alloc(sr, shr, shr->shr_root_node,
            ACE_ALL_PERMS, 0);
        if (sr->tid_tree == NULL) {
                cmn_err(CE_NOTE, "smb2_dh_import_share: "
                    "failed connect share <%s>", shr->shr_name);
                goto out;
        }
        snode = sr->tid_tree->t_snode;

        /*
         * Get the buffers we'll use to read CA handle data.
         * Also get a buffer for the stream name info.
         */
        nvl_buf = kmem_alloc(smb2_dh_max_cah_size, KM_SLEEP);
        str_info = kmem_alloc(sizeof (smb_streaminfo_t), KM_SLEEP);

        /*
         * Open the ext. attr dir under the share root and
         * import CA handles for this share.
         */
        if (smb_odir_openat(sr, snode, &od, B_FALSE) != 0) {
                cmn_err(CE_NOTE, "!Share [%s] CA import, no xattr dir?",
                    shr->shr_name);
                goto out;
        }

        eof = B_FALSE;
        do {
                /*
                 * If the kshare gets unshared before we finish,
                 * bail out so we don't hold things up.
                 */
                if (shr->shr_flags & SMB_SHRF_REMOVED)
                        break;

                /*
                 * If the server's stopping, no point importing.
                 */
                if (smb_server_is_stopping(sr->sr_server))
                        break;

                /*
                 * Read a stream name and info
                 */
                rc = smb_odir_read_streaminfo(sr, od, str_info, &eof);
                if ((rc != 0) || (eof))
                        break;

                /*
                 * Skip anything not a CA handle.
                 */
                if (!smb2_dh_match_ca_name(str_info->si_name, &id)) {
                        continue;
                }

                /*
                 * Lookup stream node and import
                 */
                str_node = NULL;
                rc = smb_fsop_lookup_name(sr, kcr, SMB_CASE_SENSITIVE,
                    snode, snode, str_info->si_name, &str_node);
                if (rc != 0) {
                        cmn_err(CE_NOTE, "Share [%s] CA import, "
                            "lookup <%s> failed rc=%d",
                            shr->shr_name, str_info->si_name, rc);
                        continue;
                }
                of = smb2_dh_import_handle(sr, str_node, nvl_buf, id);
                smb_node_release(str_node);
                if (of != NULL) {
                        smb_ofile_release(of);
                        of = NULL;
                }
                sr->fid_ofile = NULL;
                smb_lavl_flush(&sr->tid_tree->t_ofile_list);

        } while (!eof);

out:
        if (od != NULL) {
                smb_odir_close(od);
                smb_odir_release(od);
        }

        if (str_info != NULL)
                kmem_free(str_info, sizeof (smb_streaminfo_t));
        if (nvl_buf != NULL)
                kmem_free(nvl_buf, smb2_dh_max_cah_size);

        /*
         * We did a (temporary, internal) tree connect above,
         * which we need to undo before we return.  Note that
         * smb_request_free will do the final release of
         * sr->tid_tree, sr->uid_user
         */
        if (sr->tid_tree != NULL)
                smb_tree_disconnect(sr->tid_tree, B_FALSE);

        /*
         * Wake up any waiting tree connect(s).
         * See smb_tree_connect_disk().
         */
        mutex_enter(&shr->shr_mutex);
        shr->shr_import_busy = NULL;
        cv_broadcast(&shr->shr_cv);
        mutex_exit(&shr->shr_mutex);

        smb_kshare_release(sr->sr_server, shr);
        smb_request_free(sr);
}

/*
 * This returns the new ofile mostly for dtrace.
 */
static smb_ofile_t *
smb2_dh_import_handle(smb_request_t *sr, smb_node_t *str_node,
    char *nvl_buf, uint64_t persist_id)
{
        uint8_t         client_uuid[UUID_LEN];
        smb_tree_t      *tree = sr->tid_tree;
        smb_arg_open_t  *op = &sr->arg.open;
        smb_pathname_t  *pn = &op->fqi.fq_path;
        cred_t          *kcr = zone_kcred();
        struct nvlist   *nvl = NULL;
        char            *sidstr = NULL;
        smb_ofile_t     *of = NULL;
        smb_attr_t      *pa;
        boolean_t       did_open = B_FALSE;
        boolean_t       have_lease = B_FALSE;
        hrtime_t        hrt;
        uint64_t        *u64p;
        uint64_t        u64;
        uint32_t        u32;
        uint32_t        status;
        char            *s;
        uint8_t         *u8p;
        uint_t          alen;
        int             rc;

        /*
         * While we're called with arg.tcon, we now want to use
         * smb_arg_open for the rest of import, so clear it.
         */
        bzero(op, sizeof (*op));
        op->create_disposition = FILE_OPEN;

        /*
         * Read and unpack the NVL
         */
        rc = smb2_dh_read_nvlist(sr, str_node, nvl_buf, &nvl);
        if (rc != 0)
                return (NULL);

        /*
         * Known CA info version?
         */
        u32 = 0;
        rc = nvlist_lookup_uint32(nvl, "info_version", &u32);
        if (rc != 0 || u32 != smb2_ca_info_version) {
                cmn_err(CE_NOTE, "CA import (%s/%s) bad vers=%d",
                    tree->t_resource, str_node->od_name, u32);
                goto errout;
        }

        /*
         * The persist ID in the nvlist should match the one
         * encoded in the file name. (not enforced)
         */
        u64 = 0;
        rc = nvlist_lookup_uint64(nvl, "file_persistid", &u64);
        if (rc != 0 || u64 != persist_id) {
                cmn_err(CE_WARN, "CA import (%s/%s) bad id=%016" PRIx64,
                    tree->t_resource, str_node->od_name, u64);
                /* goto errout? (allow) */
        }

        /*
         * Does it belong in the share being imported?
         */
        s = NULL;
        rc = nvlist_lookup_string(nvl, "share_name", &s);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no share_name",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }
        if (smb_strcasecmp(s, tree->t_sharename, 0) != 0) {
                /* Normal (not an error) */
#ifdef DEBUG
                cmn_err(CE_NOTE, "CA import (%s/%s) other share",
                    tree->t_resource, str_node->od_name);
#endif
                goto errout;
        }

        /*
         * Get the path name (for lookup)
         */
        rc = nvlist_lookup_string(nvl, "path_name", &pn->pn_path);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no path_name",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }

        /*
         * owner sid
         */
        rc = nvlist_lookup_string(nvl, "owner_sid", &sidstr);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no owner_sid",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }

        /*
         * granted access
         */
        rc = nvlist_lookup_uint32(nvl,
            "granted_access", &op->desired_access);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no granted_access",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }

        /*
         * share access
         */
        rc = nvlist_lookup_uint32(nvl,
            "share_access", &op->share_access);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no share_access",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }

        /*
         * create options
         */
        rc = nvlist_lookup_uint32(nvl,
            "create_options", &op->create_options);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no create_options",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }

        /*
         * create guid (client-assigned)
         */
        alen = UUID_LEN;
        u8p = NULL;
        rc = nvlist_lookup_uint8_array(nvl, "file_guid", &u8p, &alen);
        if (rc != 0 || alen != UUID_LEN) {
                cmn_err(CE_NOTE, "CA import (%s/%s) bad file_guid",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }
        bcopy(u8p, op->create_guid, UUID_LEN);

        /*
         * client uuid (identifies the client)
         */
        alen = UUID_LEN;
        u8p = NULL;
        rc = nvlist_lookup_uint8_array(nvl, "client_uuid", &u8p, &alen);
        if (rc != 0 || alen != UUID_LEN) {
                cmn_err(CE_NOTE, "CA import (%s/%s) no client_uuid",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }
        bcopy(u8p, client_uuid, UUID_LEN);

        /*
         * Lease key (optional)
         */
        alen = SMB_LEASE_KEY_SZ;
        u8p = NULL;
        rc = nvlist_lookup_uint8_array(nvl, "lease_uuid", &u8p, &alen);
        if (rc == 0) {
                bcopy(u8p, op->lease_key, UUID_LEN);
                (void) nvlist_lookup_uint32(nvl,
                    "lease_state", &op->lease_state);
                (void) nvlist_lookup_uint16(nvl,
                    "lease_epoch", &op->lease_epoch);
                (void) nvlist_lookup_uint16(nvl,
                    "lease_version", &op->lease_version);
                have_lease = B_TRUE;
        } else {
                (void) nvlist_lookup_uint32(nvl,
                    "oplock_state", &op->op_oplock_state);
        }

        /*
         * Done getting what we need from the NV list.
         * (re)open the file
         */
        status = smb_common_open(sr);
        if (status != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) open failed 0x%x",
                    tree->t_resource, str_node->od_name, status);
                (void) smb_node_set_delete_on_close(str_node, kcr, 0);
                goto errout;
        }
        of = sr->fid_ofile;
        did_open = B_TRUE;

        /*
         * Now restore the rest of the SMB2 level state.
         * See smb2_create after smb_common_open
         */

        /*
         * Setup of->f_cr with owner SID
         */
        rc = smb2_dh_import_cred(of, sidstr);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) import cred failed",
                    tree->t_resource, str_node->od_name);
                goto errout;
        }

        /*
         * Use the persist ID we previously assigned.
         * Like smb_ofile_set_persistid_ph()
         */
        rc = smb_ofile_insert_persistid(of, persist_id);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) "
                    "insert_persistid rc=%d",
                    tree->t_resource, str_node->od_name, rc);
                goto errout;
        }

        /*
         * Like smb2_lease_create()
         *
         * Lease state is stored in each persistent handle, but
         * only one handle has the state we want.  As we import
         * each handle, "upgrade" the lease if the handle we're
         * importing has a "better" lease state (higher epoch or
         * more cache rights).  After all handles are imported,
         * that will get the lease to the right state.
         */
        if (have_lease) {
                smb_lease_t *ls;
                status = smb2_lease_create(sr, client_uuid);
                if (status != 0) {
                        cmn_err(CE_NOTE, "CA import (%s/%s) get lease 0x%x",
                            tree->t_resource, str_node->od_name, status);
                        goto errout;
                }
                ls = of->f_lease;

                /* Use most current "epoch". */
                mutex_enter(&ls->ls_mutex);
                if (ls->ls_epoch < op->lease_epoch)
                        ls->ls_epoch = op->lease_epoch;
                mutex_exit(&ls->ls_mutex);

                /*
                 * Get the lease (and oplock)
                 * uses op->lease_state
                 */
                op->op_oplock_level = SMB2_OPLOCK_LEVEL_LEASE;
                smb2_lease_acquire(sr);

        } else {
                /*
                 * No lease; maybe get an oplock
                 * uses: op->op_oplock_level
                 */
                if (op->op_oplock_state & OPLOCK_LEVEL_BATCH) {
                        op->op_oplock_level = SMB2_OPLOCK_LEVEL_BATCH;
                } else if (op->op_oplock_state & OPLOCK_LEVEL_ONE) {
                        op->op_oplock_level = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
                } else if (op->op_oplock_state & OPLOCK_LEVEL_TWO) {
                        op->op_oplock_level = SMB2_OPLOCK_LEVEL_II;
                } else {
                        op->op_oplock_level = SMB2_OPLOCK_LEVEL_NONE;
                }
                smb2_oplock_acquire(sr);
        }

        /*
         * Byte range locks
         */
        alen = 0;
        u64p = NULL;
        if (nvlist_lookup_uint64_array(nvl, "locks", &u64p, &alen) == 0) {
                uint_t  i;
                uint_t nlocks = alen / 3;
                struct nvlk     *nlp;

                nlp = (struct nvlk *)u64p;
                for (i = 0; i < nlocks; i++) {
                        status = smb_lock_range(
                            sr,
                            nlp->lk_start,
                            nlp->lk_len,
                            nlp->lk_pid,
                            nlp->lk_type,
                            0);
                        if (status != 0) {
                                cmn_err(CE_NOTE, "CA import (%s/%s) "
                                    "get lock %d failed 0x%x",
                                    tree->t_resource,
                                    str_node->od_name,
                                    i, status);
                        }
                        nlp++;
                }
        }
        alen = SMB_OFILE_LSEQ_MAX;
        u8p = NULL;
        if (nvlist_lookup_uint8_array(nvl, "lockseq", &u8p, &alen) == 0) {
                if (alen != SMB_OFILE_LSEQ_MAX) {
                        cmn_err(CE_NOTE, "CA import (%s/%s) "
                            "get lockseq bad len=%d",
                            tree->t_resource,
                            str_node->od_name,
                            alen);
                } else {
                        mutex_enter(&of->f_mutex);
                        bcopy(u8p, of->f_lock_seq, alen);
                        mutex_exit(&of->f_mutex);
                }
        }

        /*
         * Optional "sticky" times (set pending attributes)
         */
        mutex_enter(&of->f_mutex);
        pa = &of->f_pending_attr;
        if (nvlist_lookup_hrtime(nvl, "atime", &hrt) == 0) {
                hrt2ts(hrt, &pa->sa_vattr.va_atime);
                pa->sa_mask |= SMB_AT_ATIME;
        }
        if (nvlist_lookup_hrtime(nvl, "mtime", &hrt) == 0) {
                hrt2ts(hrt, &pa->sa_vattr.va_mtime);
                pa->sa_mask |= SMB_AT_MTIME;
        }
        if (nvlist_lookup_hrtime(nvl, "ctime", &hrt) == 0) {
                hrt2ts(hrt, &pa->sa_vattr.va_ctime);
                pa->sa_mask |= SMB_AT_CTIME;
        }
        mutex_exit(&of->f_mutex);

        /*
         * Make durable and persistent.
         * See smb2_dh_make_persistent()
         */
        of->dh_vers = SMB2_DURABLE_V2;
        bcopy(op->create_guid, of->dh_create_guid, UUID_LEN);
        of->dh_persist = B_TRUE;
        of->dh_nvfile = str_node;
        smb_node_ref(str_node);
        of->dh_nvlist = nvl;
        nvl = NULL;

        /*
         * Now make it state orphaned...
         * See smb_ofile_drop(), then
         * smb_ofile_save_dh()
         */
        mutex_enter(&of->f_mutex);
        of->f_state = SMB_OFILE_STATE_SAVE_DH;
        of->dh_timeout_offset = MSEC2NSEC(smb2_persist_timeout);
        mutex_exit(&of->f_mutex);

        /*
         * Finished!
         */
        return (of);

errout:
        if (did_open) {
                smb_ofile_close(of, 0);
                smb_ofile_release(of);
        } else {
                ASSERT(of == NULL);
        }

        if (nvl != NULL)
                nvlist_free(nvl);

        return (NULL);
}

static int
smb2_dh_read_nvlist(smb_request_t *sr, smb_node_t *node,
    char *fbuf, struct nvlist **nvlpp)
{
        smb_attr_t      attr;
        iovec_t         iov;
        uio_t           uio;
        smb_tree_t      *tree = sr->tid_tree;
        cred_t          *kcr = zone_kcred();
        size_t          flen;
        int             rc;

        bzero(&attr, sizeof (attr));
        attr.sa_mask = SMB_AT_SIZE;
        rc = smb_node_getattr(NULL, node, kcr, NULL, &attr);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) getattr rc=%d",
                    tree->t_resource, node->od_name, rc);
                return (rc);
        }

        if (attr.sa_vattr.va_size < 4 ||
            attr.sa_vattr.va_size > smb2_dh_max_cah_size) {
                cmn_err(CE_NOTE, "CA import (%s/%s) bad size=%" PRIu64,
                    tree->t_resource, node->od_name,
                    (uint64_t)attr.sa_vattr.va_size);
                return (EINVAL);
        }
        flen = (size_t)attr.sa_vattr.va_size;

        bzero(&uio, sizeof (uio));
        iov.iov_base = fbuf;
        iov.iov_len = flen;
        uio.uio_iov = &iov;
        uio.uio_iovcnt = 1;
        uio.uio_resid = flen;
        uio.uio_segflg = UIO_SYSSPACE;
        uio.uio_extflg = UIO_COPY_DEFAULT;
        rc = smb_fsop_read(sr, kcr, node, NULL, &uio, 0);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) read, rc=%d",
                    tree->t_resource, node->od_name, rc);
                return (rc);
        }
        if (uio.uio_resid != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) short read",
                    tree->t_resource, node->od_name);
                return (EIO);
        }

        rc = nvlist_unpack(fbuf, flen, nvlpp, KM_SLEEP);
        if (rc != 0) {
                cmn_err(CE_NOTE, "CA import (%s/%s) unpack, rc=%d",
                    tree->t_resource, node->od_name, rc);
                return (rc);
        }

        return (0);
}

/*
 * Setup a vestigial credential in of->f_cr just good enough for
 * smb_is_same_user to determine if the caller owned this ofile.
 * At reconnect, of->f_cr will be replaced with the caller's.
 */
static int
smb2_dh_import_cred(smb_ofile_t *of, char *sidstr)
{
#ifdef  _FAKE_KERNEL
        _NOTE(ARGUNUSED(sidstr))
        /* fksmbd doesn't have real credentials. */
        of->f_cr = CRED();
        crhold(of->f_cr);
#else
        char tmpstr[SMB_SID_STRSZ];
        ksid_t          ksid;
        cred_t          *cr, *oldcr;
        int             rc;

        (void) strlcpy(tmpstr, sidstr, sizeof (tmpstr));
        bzero(&ksid, sizeof (ksid));

        rc = smb_sid_splitstr(tmpstr, &ksid.ks_rid);
        if (rc != 0)
                return (rc);
        cr = crget();

        ksid.ks_domain = ksid_lookupdomain(tmpstr);
        crsetsid(cr, &ksid, KSID_USER);
        ksiddomain_hold(ksid.ks_domain);
        crsetsid(cr, &ksid, KSID_OWNER);

        /*
         * Just to avoid leaving the KSID_GROUP slot NULL,
         * put the "everyone" SID there (S-1-1-0).
         */
        ksid.ks_domain = ksid_lookupdomain("S-1-1");
        ksid.ks_rid = 0;
        crsetsid(cr, &ksid, KSID_GROUP);

        oldcr = of->f_cr;
        of->f_cr = cr;
        if (oldcr != NULL)
                crfree(oldcr);
#endif

        return (0);
}

/*
 * Set Delete-on-Close (DoC) on the persistent state file so it will be
 * removed when the last ref. goes away (in smb2_dh_close_persistent).
 *
 * This is called in just two places:
 * (1) SMB2_close request -- client tells us to destroy the handle.
 * (2) smb2_dh_expire -- client has forgotten about this handle.
 * All other (server-initiated) close calls should leave these
 * persistent state files in the file system.
 */
void
smb2_dh_setdoc_persistent(smb_ofile_t *of)
{
        smb_node_t *strnode;
        uint32_t status;

        mutex_enter(&of->dh_nvlock);
        if ((strnode = of->dh_nvfile) != NULL)
                smb_node_ref(strnode);
        mutex_exit(&of->dh_nvlock);

        if (strnode != NULL) {
                status = smb_node_set_delete_on_close(strnode,
                    zone_kcred(), SMB_CASE_SENSITIVE);
                if (status != 0) {
                        cmn_err(CE_WARN, "Can't set DoC on CA file: %s",
                            strnode->od_name);
                        DTRACE_PROBE1(rm__ca__err, smb_ofile_t *, of);
                }
                smb_node_release(strnode);
        }
}

/*
 * During ofile close, free the persistent handle state nvlist and
 * drop our reference to the state file node (which may unlink it
 * if smb2_dh_setdoc_persistent was called).
 */
void
smb2_dh_close_persistent(smb_ofile_t *of)
{
        smb_node_t      *strnode;
        struct nvlist   *nvl;

        /*
         * Clear out nvlist and stream linkage
         */
        mutex_enter(&of->dh_nvlock);
        strnode = of->dh_nvfile;
        of->dh_nvfile = NULL;
        nvl = of->dh_nvlist;
        of->dh_nvlist = NULL;
        mutex_exit(&of->dh_nvlock);

        if (nvl != NULL)
                nvlist_free(nvl);

        if (strnode != NULL)
                smb_node_release(strnode);
}

/*
 * Make this durable handle persistent.
 * If we succeed, set of->dh_persist = TRUE.
 */
int
smb2_dh_make_persistent(smb_request_t *sr, smb_ofile_t *of)
{
        char            fname[DH_SN_SIZE];
        char            sidstr[SMB_SID_STRSZ];
        smb_attr_t      attr;
        smb_arg_open_t  *op = &sr->arg.open;
        cred_t          *kcr = zone_kcred();
        smb_node_t      *dnode = of->f_tree->t_snode;
        smb_node_t      *fnode = NULL;
        ksid_t          *ksid;
        int             rc;

        ASSERT(of->dh_nvfile == NULL);

        /*
         * Create the persistent handle nvlist file.
         * It's a named stream in the share root.
         */
        smb2_dh_make_stream_name(fname, sizeof (fname), of->f_persistid);

        bzero(&attr, sizeof (attr));
        attr.sa_mask = SMB_AT_TYPE | SMB_AT_MODE | SMB_AT_SIZE;
        attr.sa_vattr.va_type = VREG;
        attr.sa_vattr.va_mode = 0640;
        attr.sa_vattr.va_size = 4;
        rc = smb_fsop_create(sr, kcr, dnode, fname, &attr, &fnode);
        if (rc != 0)
                return (rc);

        mutex_enter(&of->dh_nvlock);

        /* fnode is held. rele in smb2_dh_close_persistent */
        of->dh_nvfile = fnode;
        (void) nvlist_alloc(&of->dh_nvlist, NV_UNIQUE_NAME, KM_SLEEP);

        /*
         * Want the ksid as a string
         */
        ksid = crgetsid(of->f_user->u_cred, KSID_USER);
        (void) snprintf(sidstr, sizeof (sidstr), "%s-%u",
            ksid->ks_domain->kd_name, ksid->ks_rid);

        /*
         * Fill in the fixed parts of the nvlist
         */
        (void) nvlist_add_uint32(of->dh_nvlist,
            "info_version", smb2_ca_info_version);
        (void) nvlist_add_string(of->dh_nvlist,
            "owner_sid", sidstr);
        (void) nvlist_add_string(of->dh_nvlist,
            "share_name", of->f_tree->t_sharename);
        (void) nvlist_add_uint64(of->dh_nvlist,
            "file_persistid", of->f_persistid);
        (void) nvlist_add_uint8_array(of->dh_nvlist,
            "file_guid", of->dh_create_guid, UUID_LEN);
        (void) nvlist_add_string(of->dh_nvlist,
            "client_ipaddr", sr->session->ip_addr_str);
        (void) nvlist_add_uint8_array(of->dh_nvlist,
            "client_uuid", sr->session->clnt_uuid, UUID_LEN);
        (void) nvlist_add_string(of->dh_nvlist,
            "path_name", op->fqi.fq_path.pn_path);
        (void) nvlist_add_uint32(of->dh_nvlist,
            "granted_access", of->f_granted_access);
        (void) nvlist_add_uint32(of->dh_nvlist,
            "share_access", of->f_share_access);
        (void) nvlist_add_uint32(of->dh_nvlist,
            "create_options", of->f_create_options);
        if (of->f_lease != NULL) {
                smb_lease_t *ls = of->f_lease;
                (void) nvlist_add_uint8_array(of->dh_nvlist,
                    "lease_uuid", ls->ls_key, 16);
                (void) nvlist_add_uint32(of->dh_nvlist,
                    "lease_state", ls->ls_state);
                (void) nvlist_add_uint16(of->dh_nvlist,
                    "lease_epoch", ls->ls_epoch);
                (void) nvlist_add_uint16(of->dh_nvlist,
                    "lease_version", ls->ls_version);
        } else {
                (void) nvlist_add_uint32(of->dh_nvlist,
                    "oplock_state", of->f_oplock.og_state);
        }
        mutex_exit(&of->dh_nvlock);

        smb2_dh_update_locks(sr, of);

        /* Tell sr update nvlist file */
        sr->dh_nvl_dirty = B_TRUE;

        return (0);
}

void
smb2_dh_update_nvfile(smb_request_t *sr)
{
        smb_attr_t      attr;
        iovec_t         iov;
        uio_t           uio;
        smb_ofile_t     *of = sr->fid_ofile;
        cred_t          *kcr = zone_kcred();
        char            *buf = NULL;
        size_t          buflen = 0;
        uint32_t        wcnt;
        int             rc;

        if (of == NULL || of->dh_persist == B_FALSE)
                return;

        mutex_enter(&of->dh_nvlock);
        if (of->dh_nvlist == NULL || of->dh_nvfile == NULL) {
                mutex_exit(&of->dh_nvlock);
                return;
        }

        rc = nvlist_size(of->dh_nvlist, &buflen, NV_ENCODE_XDR);
        if (rc != 0)
                goto out;
        buf = kmem_zalloc(buflen, KM_SLEEP);

        rc = nvlist_pack(of->dh_nvlist, &buf, &buflen,
            NV_ENCODE_XDR, KM_SLEEP);
        if (rc != 0)
                goto out;

        bzero(&attr, sizeof (attr));
        attr.sa_mask = SMB_AT_SIZE;
        attr.sa_vattr.va_size = buflen;
        rc = smb_node_setattr(sr, of->dh_nvfile, kcr, NULL, &attr);
        if (rc != 0)
                goto out;

        bzero(&uio, sizeof (uio));
        iov.iov_base = (void *) buf;
        iov.iov_len = buflen;
        uio.uio_iov = &iov;
        uio.uio_iovcnt = 1;
        uio.uio_resid = buflen;
        uio.uio_segflg = UIO_SYSSPACE;
        uio.uio_extflg = UIO_COPY_DEFAULT;
        rc = smb_fsop_write(sr, kcr, of->dh_nvfile,
            NULL, &uio, &wcnt, 0);
        if (rc == 0 && wcnt != buflen)
                rc = EIO;

out:
        mutex_exit(&of->dh_nvlock);

        if (rc != 0) {
                cmn_err(CE_WARN,
                    "clnt(%s) failed to update persistent handle, rc=%d",
                    sr->session->ip_addr_str, rc);
        }

        if (buf != NULL) {
                kmem_free(buf, buflen);
        }
}

/*
 * Called after f_oplock (and lease) changes
 * If lease, update: lease_state, lease_epoch
 * else (oplock) update: oplock_state
 */
void
smb2_dh_update_oplock(smb_request_t *sr, smb_ofile_t *of)
{
        smb_lease_t *ls;

        mutex_enter(&of->dh_nvlock);
        if (of->dh_nvlist == NULL) {
                mutex_exit(&of->dh_nvlock);
                return;
        }

        if (of->f_lease != NULL) {
                ls = of->f_lease;
                (void) nvlist_add_uint32(of->dh_nvlist,
                    "lease_state", ls->ls_state);
                (void) nvlist_add_uint16(of->dh_nvlist,
                    "lease_epoch", ls->ls_epoch);
        } else {
                (void) nvlist_add_uint32(of->dh_nvlist,
                    "oplock_state", of->f_oplock.og_state);
        }
        mutex_exit(&of->dh_nvlock);

        sr->dh_nvl_dirty = B_TRUE;
}

/*
 * Save locks from this ofile as an array of uint64_t, where the
 * elements are triplets: (start, length, (pid << 32) | type)
 * Note pid should always be zero for SMB2, so we could use
 * that 32-bit spot for something else if needed.
 */
void
smb2_dh_update_locks(smb_request_t *sr, smb_ofile_t *of)
{
        uint8_t         lseq[SMB_OFILE_LSEQ_MAX];
        smb_node_t      *node = of->f_node;
        smb_llist_t     *llist = &node->n_lock_list;
        size_t          vec_sz; // storage size
        uint_t          my_cnt = 0;
        uint64_t        *vec = NULL;
        struct nvlk     *nlp;
        smb_lock_t      *lock;

        smb_llist_enter(llist, RW_READER);
        vec_sz = (llist->ll_count + 1) * sizeof (struct nvlk);
        vec = kmem_alloc(vec_sz, KM_SLEEP);
        nlp = (struct nvlk *)vec;
        for (lock = smb_llist_head(llist);
            lock != NULL;
            lock = smb_llist_next(llist, lock)) {
                if (lock->l_file != of)
                        continue;
                nlp->lk_start = lock->l_start;
                nlp->lk_len = lock->l_length;
                nlp->lk_pid = lock->l_pid;
                nlp->lk_type = lock->l_type;
                nlp++;
                my_cnt++;
        }
        smb_llist_exit(llist);

        mutex_enter(&of->f_mutex);
        bcopy(of->f_lock_seq, lseq, sizeof (lseq));
        mutex_exit(&of->f_mutex);

        mutex_enter(&of->dh_nvlock);
        if (of->dh_nvlist != NULL) {

                (void) nvlist_add_uint64_array(of->dh_nvlist,
                    "locks", vec, my_cnt * 3);

                (void) nvlist_add_uint8_array(of->dh_nvlist,
                    "lockseq", lseq, sizeof (lseq));
        }
        mutex_exit(&of->dh_nvlock);

        kmem_free(vec, vec_sz);

        sr->dh_nvl_dirty = B_TRUE;
}

/*
 * Save "sticky" times.
 */
void
smb2_dh_update_times(smb_request_t *sr, smb_ofile_t *of, smb_attr_t *attr)
{
        hrtime_t t;

        mutex_enter(&of->dh_nvlock);
        if (of->dh_nvlist == NULL) {
                mutex_exit(&of->dh_nvlock);
                return;
        }

        if (attr->sa_mask & SMB_AT_ATIME) {
                t = ts2hrt(&attr->sa_vattr.va_atime);
                (void) nvlist_add_hrtime(of->dh_nvlist, "atime", t);
        } else {
                (void) nvlist_remove_all(of->dh_nvlist, "atime");
        }

        if (attr->sa_mask & SMB_AT_MTIME) {
                t = ts2hrt(&attr->sa_vattr.va_mtime);
                (void) nvlist_add_hrtime(of->dh_nvlist, "mtime", t);
        } else {
                (void) nvlist_remove_all(of->dh_nvlist, "mtime");
        }

        if (attr->sa_mask & SMB_AT_CTIME) {
                t = ts2hrt(&attr->sa_vattr.va_ctime);
                (void) nvlist_add_hrtime(of->dh_nvlist, "ctime", t);
        } else {
                (void) nvlist_remove_all(of->dh_nvlist, "ctime");
        }

        mutex_exit(&of->dh_nvlock);

        sr->dh_nvl_dirty = B_TRUE;
}


/*
 * Requirements for ofile found during reconnect (MS-SMB2 3.3.5.9.7):
 * - security descriptor must match provided descriptor
 *
 * If file is leased:
 * - lease must be requested
 * - client guid must match session guid
 * - file name must match given name
 * - lease key must match provided lease key
 * If file is not leased:
 * - Lease must not be requested
 *
 * dh_v2 only:
 * - SMB2_DHANDLE_FLAG_PERSISTENT must be set if dh_persist is true
 * - SMB2_DHANDLE_FLAG_PERSISTENT must not be set if dh_persist is false
 * - desired access, share access, and create_options must be ignored
 * - createguid must match
 */
static uint32_t
smb2_dh_reconnect_checks(smb_request_t *sr, smb_ofile_t *of)
{
        smb_arg_open_t  *op = &sr->sr_open;
        char *fname;

        if (of->f_lease != NULL) {
                if (bcmp(sr->session->clnt_uuid,
                    of->f_lease->ls_clnt, 16) != 0)
                        return (NT_STATUS_OBJECT_NAME_NOT_FOUND);

                if (op->op_oplock_level != SMB2_OPLOCK_LEVEL_LEASE)
                        return (NT_STATUS_OBJECT_NAME_NOT_FOUND);
                if (bcmp(op->lease_key, of->f_lease->ls_key,
                    SMB_LEASE_KEY_SZ) != 0)
                        return (NT_STATUS_OBJECT_NAME_NOT_FOUND);

                /*
                 * We're supposed to check the name is the same.
                 * Not really necessary to do this, so just do
                 * minimal effort (check last component)
                 */
                fname = strrchr(op->fqi.fq_path.pn_path, '\\');
                if (fname != NULL)
                        fname++;
                else
                        fname = op->fqi.fq_path.pn_path;
                if (smb_strcasecmp(fname, of->f_node->od_name, 0) != 0) {
#ifdef  DEBUG
                        cmn_err(CE_NOTE, "reconnect name <%s> of name <%s>",
                            fname, of->f_node->od_name);
#endif
                        return (NT_STATUS_INVALID_PARAMETER);
                }
        } else {
                if (op->op_oplock_level == SMB2_OPLOCK_LEVEL_LEASE)
                        return (NT_STATUS_OBJECT_NAME_NOT_FOUND);
        }

        if (op->dh_vers == SMB2_DURABLE_V2) {
                boolean_t op_persist =
                    ((op->dh_v2_flags & SMB2_DHANDLE_FLAG_PERSISTENT) != 0);
                if (of->dh_persist != op_persist)
                        return (NT_STATUS_OBJECT_NAME_NOT_FOUND);
                if (memcmp(op->create_guid, of->dh_create_guid, UUID_LEN))
                        return (NT_STATUS_OBJECT_NAME_NOT_FOUND);
        }

        if (!smb_is_same_user(sr->user_cr, of->f_cr))
                return (NT_STATUS_ACCESS_DENIED);

        return (NT_STATUS_SUCCESS);
}

/*
 * [MS-SMB2] 3.3.5.9.7 and 3.3.5.9.12 (durable reconnect v1/v2)
 *
 * Looks up an ofile on the server's sv_dh_list by the persistid.
 * If found, it validates the request.
 * (see smb2_dh_reconnect_checks() for details)
 * If the checks are passed, add it onto the new tree's list.
 *
 * Note that the oplock break code path can get to an ofile via the node
 * ofile list.  It starts with a ref taken in smb_ofile_hold_olbrk, which
 * waits if the ofile is found in state RECONNECT.  That wait happens with
 * the node ofile list lock held as reader, and the oplock mutex held.
 * Implications of that are: While we're in state RECONNECT, we shoud NOT
 * block (at least, not for long) and must not try to enter any of the
 * node ofile list lock or oplock mutex.  Thankfully, we don't need to
 * enter those while reclaiming an orphaned ofile.
 */
uint32_t
smb2_dh_reconnect(smb_request_t *sr)
{
        smb_arg_open_t  *op = &sr->sr_open;
        smb_tree_t *tree = sr->tid_tree;
        smb_ofile_t *of;
        cred_t *old_cr;
        uint32_t status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
        uint16_t fid = 0;

        if (smb_idpool_alloc(&tree->t_fid_pool, &fid))
                return (NT_STATUS_TOO_MANY_OPENED_FILES);

        /* Find orphaned handle. */
        of = smb_ofile_lookup_by_persistid(sr, op->dh_fileid.persistent);
        if (of == NULL)
                goto errout;

        mutex_enter(&of->f_mutex);
        if (of->f_state != SMB_OFILE_STATE_ORPHANED) {
                mutex_exit(&of->f_mutex);
                goto errout;
        }

        status = smb2_dh_reconnect_checks(sr, of);
        if (status != NT_STATUS_SUCCESS) {
                mutex_exit(&of->f_mutex);
                goto errout;
        }

        /*
         * Note: cv_broadcast(&of->f_cv) when we're
         * done messing around in this state.
         * See: smb_ofile_hold_olbrk()
         */
        of->f_state = SMB_OFILE_STATE_RECONNECT;
        mutex_exit(&of->f_mutex);

        /*
         * At this point, we should be the only thread with a ref on the
         * ofile, and the RECONNECT state should prevent new refs from
         * being granted, or other durable threads from observing or
         * reclaiming it. Put this ofile in the new tree, similar to
         * the last part of smb_ofile_open.
         */

        old_cr = of->f_cr;
        of->f_cr = sr->user_cr;
        crhold(of->f_cr);
        crfree(old_cr);

        of->f_session = sr->session; /* hold is via user and tree */
        smb_user_hold_internal(sr->uid_user);
        of->f_user = sr->uid_user;
        smb_tree_hold_internal(tree);
        of->f_tree = tree;
        of->f_fid = fid;

        smb_lavl_enter(&tree->t_ofile_list, RW_WRITER);
        smb_lavl_insert(&tree->t_ofile_list, of);
        smb_lavl_exit(&tree->t_ofile_list);
        atomic_inc_32(&tree->t_open_files);
        atomic_inc_32(&sr->session->s_file_cnt);

        /*
         * The ofile is now in the caller's session & tree.
         *
         * In case smb_ofile_hold or smb_oplock_send_break() are
         * waiting for state RECONNECT to complete, wakeup.
         */
        mutex_enter(&of->f_mutex);
        of->dh_expire_time = 0;
        of->f_state = SMB_OFILE_STATE_OPEN;
        cv_broadcast(&of->f_cv);
        mutex_exit(&of->f_mutex);

        /*
         * The ofile is now visible in the new session.
         * From here, this is similar to the last part of
         * smb_common_open().
         */
        op->fqi.fq_fattr.sa_mask = SMB_AT_ALL;
        (void) smb_node_getattr(sr, of->f_node, zone_kcred(), of,
            &op->fqi.fq_fattr);

        /*
         * Set up the fileid and dosattr in open_param for response
         */
        op->fileid = op->fqi.fq_fattr.sa_vattr.va_nodeid;
        op->dattr = op->fqi.fq_fattr.sa_dosattr;

        /*
         * Set up the file type in open_param for the response
         * The ref. from ofile lookup is "given" to fid_ofile.
         */
        op->ftype = SMB_FTYPE_DISK;
        sr->smb_fid = of->f_fid;
        sr->fid_ofile = of;

        if (smb_node_is_file(of->f_node)) {
                op->dsize = op->fqi.fq_fattr.sa_vattr.va_size;
        } else {
                /* directory or symlink */
                op->dsize = 0;
        }

        op->create_options = 0; /* no more modifications wanted */
        op->action_taken = SMB_OACT_OPENED;
        return (NT_STATUS_SUCCESS);

errout:
        if (of != NULL)
                smb_ofile_release(of);
        if (fid != 0)
                smb_idpool_free(&tree->t_fid_pool, fid);

        return (status);
}

/*
 * Durable handle expiration
 * ofile state is _EXPIRED
 */
static void
smb2_dh_expire(void *arg)
{
        smb_ofile_t *of = (smb_ofile_t *)arg;

        if (of->dh_persist)
                smb2_dh_setdoc_persistent(of);
        smb_ofile_close(of, 0);
        smb_ofile_release(of);
}

/*
 * Called once a minute to do expiration of durable handles.
 *
 * Normally expired durable handles should be in state "orphaned",
 * having transitioned from state SAVE_DH through SAVING to state
 * ORPHANED after all ofile references go away.  If an ofile has
 * leaked references and the client disconnects, it will be found
 * here still in state SAVE_DH and past it's expiration time.
 * Call smb2_dh_expire for these as well, which will move them
 * from state SAVE_DH to state CLOSING, so they can no longer
 * cause sharing violations for new opens.
 */
void
smb2_durable_timers(smb_server_t *sv)
{
        smb_hash_t *hash;
        smb_llist_t *bucket;
        smb_ofile_t *of;
        hrtime_t now;
        int i;

        hash = sv->sv_persistid_ht;
        now = gethrtime();

        for (i = 0; i < hash->num_buckets; i++) {
                bucket = &hash->buckets[i].b_list;
                smb_llist_enter(bucket, RW_READER);
                for (of = smb_llist_head(bucket);
                    of != NULL;
                    of = smb_llist_next(bucket, of)) {
                        SMB_OFILE_VALID(of);

                        /*
                         * Check outside the mutex first to avoid some
                         * mutex_enter work in this loop.  If the state
                         * changes under foot, the worst that happens
                         * is we either enter the mutex when we might
                         * not have needed to, or we miss some DH in
                         * this pass and get it on the next.
                         */
                        if (of->f_state != SMB_OFILE_STATE_ORPHANED &&
                            of->f_state != SMB_OFILE_STATE_SAVE_DH)
                                continue;

                        mutex_enter(&of->f_mutex);
                        if ((of->f_state == SMB_OFILE_STATE_ORPHANED ||
                            of->f_state == SMB_OFILE_STATE_SAVE_DH) &&
                            of->dh_expire_time != 0 &&
                            of->dh_expire_time <= now) {

                                of->f_state = SMB_OFILE_STATE_EXPIRED;
                                /* inline smb_ofile_hold_internal() */
                                of->f_refcnt++;
                                smb_llist_post(bucket, of, smb2_dh_expire);
                        }
                        mutex_exit(&of->f_mutex);
                }
                smb_llist_exit(bucket);
        }
}

/*
 * This is called when we're about to add a new open to some node.
 * If we still have orphaned durable handles on this node, let's
 * assume the client has lost interest in those and close them,
 * otherwise we might conflict with our own orphaned handles.
 *
 * We need this because we import persistent handles "speculatively"
 * during share import (before the client ever asks for reconnect).
 * That allows us to avoid any need for a "create blackout" (or
 * "grace period") because the imported handles prevent unwanted
 * conflicting opens from other clients.  However, if some client
 * "forgets" about a persistent handle (*cough* Hyper-V) and tries
 * a new (conflicting) open instead of a reconnect, that might
 * fail unless we expire our orphaned durables handle first.
 *
 * Logic similar to smb_node_open_check()
 */
void
smb2_dh_close_my_orphans(smb_request_t *sr, smb_ofile_t *new_of)
{
        smb_node_t *node = new_of->f_node;
        smb_ofile_t *of;

        SMB_NODE_VALID(node);

        smb_llist_enter(&node->n_ofile_list, RW_READER);
        for (of = smb_llist_head(&node->n_ofile_list);
            of != NULL;
            of = smb_llist_next(&node->n_ofile_list, of)) {

                /* Same client? */
                if (of->f_lease != NULL &&
                    bcmp(sr->session->clnt_uuid,
                    of->f_lease->ls_clnt, 16) != 0)
                        continue;

                if (!smb_is_same_user(sr->user_cr, of->f_cr))
                        continue;

                mutex_enter(&of->f_mutex);
                if (of->f_state == SMB_OFILE_STATE_ORPHANED ||
                    of->f_state == SMB_OFILE_STATE_SAVE_DH) {
                        of->f_state = SMB_OFILE_STATE_EXPIRED;
                        /* inline smb_ofile_hold_internal() */
                        of->f_refcnt++;
                        smb_llist_post(&node->n_ofile_list,
                            of, smb2_dh_expire);
                }
                mutex_exit(&of->f_mutex);
        }

        smb_llist_exit(&node->n_ofile_list);
}

/*
 * Called for each orphaned DH during shutdown.
 * Clean out any in-memory state, but leave any
 * on-disk persistent handle state in place.
 */
static void
smb2_dh_cleanup(void *arg)
{
        smb_ofile_t *of = (smb_ofile_t *)arg;
        smb_node_t *strnode;
        struct nvlist *nvl;

        /*
         * Intentionally skip smb2_dh_close_persistent by
         * clearing dh_nvfile before smb_ofile_close().
         */
        mutex_enter(&of->dh_nvlock);
        strnode = of->dh_nvfile;
        of->dh_nvfile = NULL;
        nvl = of->dh_nvlist;
        of->dh_nvlist = NULL;
        mutex_exit(&of->dh_nvlock);

        if (nvl != NULL)
                nvlist_free(nvl);

        if (strnode != NULL)
                smb_node_release(strnode);

        smb_ofile_close(of, 0);
        smb_ofile_release(of);
}

/*
 * Clean out durable handles during shutdown.
 *
 * Like, smb2_durable_timers but cleanup only in-memory state,
 * and leave any persistent state there for later reconnect.
 */
void
smb2_dh_shutdown(smb_server_t *sv)
{
        static const smb_oplock_grant_t og0 = { 0 };
        smb_hash_t *hash;
        smb_llist_t *bucket;
        smb_ofile_t *of;
        int i;

        hash = sv->sv_persistid_ht;

        for (i = 0; i < hash->num_buckets; i++) {
                bucket = &hash->buckets[i].b_list;
                smb_llist_enter(bucket, RW_READER);
                of = smb_llist_head(bucket);
                while (of != NULL) {
                        SMB_OFILE_VALID(of);
                        mutex_enter(&of->f_mutex);

                        switch (of->f_state) {
                        case SMB_OFILE_STATE_ORPHANED:
                        case SMB_OFILE_STATE_SAVE_DH:
                                of->f_state = SMB_OFILE_STATE_EXPIRED;
                                /* inline smb_ofile_hold_internal() */
                                of->f_refcnt++;
                                smb_llist_post(bucket, of, smb2_dh_cleanup);
                                break;

                        default:
                                /*
                                 * Should not be possible, but try to
                                 * make this zombie ofile harmless.
                                 */
                                cmn_err(CE_NOTE, "!dh_shutdown found "
                                    "of = %p with invalid state = %d",
                                    (void *)of, of->f_state);
                                DTRACE_PROBE1(bad_ofile, smb_ofile_t *, of);
                                ASSERT(0);
                                of->f_oplock = og0;
                                break;
                        }
                        mutex_exit(&of->f_mutex);
                        of = smb_llist_next(bucket, of);
                }
                smb_llist_exit(bucket);
        }

#ifdef  DEBUG
        for (i = 0; i < hash->num_buckets; i++) {
                bucket = &hash->buckets[i].b_list;
                smb_llist_enter(bucket, RW_READER);
                of = smb_llist_head(bucket);
                while (of != NULL) {
                        SMB_OFILE_VALID(of);
                        cmn_err(CE_NOTE, "dh_shutdown leaked of=%p",
                            (void *)of);
                        of = smb_llist_next(bucket, of);
                }
                smb_llist_exit(bucket);
        }
#endif  // DEBUG
}

uint32_t
smb2_fsctl_set_resilient(smb_request_t *sr, smb_fsctl_t *fsctl)
{
        uint32_t timeout;
        smb_ofile_t *of = sr->fid_ofile;

        /*
         * Note: The spec does not explicitly prohibit resilient directories
         * the same way it prohibits durable directories. We prohibit them
         * anyway as a simplifying assumption, as there doesn't seem to be
         * much use for it. (HYPER-V only seems to use it on files anyway)
         */
        if (fsctl->InputCount < 8 || !smb_node_is_file(of->f_node))
                return (NT_STATUS_INVALID_PARAMETER);

        (void) smb_mbc_decodef(fsctl->in_mbc, "l4.",
            &timeout); /* milliseconds */

        if (smb2_enable_dh == 0)
                return (NT_STATUS_NOT_SUPPORTED);

        /*
         * The spec wants us to return INVALID_PARAMETER if the timeout
         * is too large, but we have no way of informing the client
         * what an appropriate timeout is, so just set the timeout to
         * our max and return SUCCESS.
         */
        if (timeout == 0)
                timeout = smb2_res_def_timeout;
        if (timeout > smb2_res_max_timeout)
                timeout = smb2_res_max_timeout;

        mutex_enter(&of->f_mutex);
        of->dh_vers = SMB2_RESILIENT;
        of->dh_timeout_offset = MSEC2NSEC(timeout);
        mutex_exit(&of->f_mutex);

        return (NT_STATUS_SUCCESS);
}