/*
 * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2020 Tintri by DDN, Inc. All rights reserved.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright 2022-2023 RackTop Systems, Inc.
 */

/*
 * General Structures Layout
 * -------------------------
 *
 * This is a simplified diagram showing the relationship between most of the
 * main structures.
 *
 * +-------------------+
 * |     SMB_INFO      |
 * +-------------------+
 *          |
 *          |
 *          v
 * +-------------------+       +-------------------+      +-------------------+
 * |     SESSION       |<----->|     SESSION       |......|      SESSION      |
 * +-------------------+       +-------------------+      +-------------------+
 *   |          |
 *   |          |
 *   |          v
 *   |  +-------------------+     +-------------------+   +-------------------+
 *   |  |       USER        |<--->|       USER        |...|       USER        |
 *   |  +-------------------+     +-------------------+   +-------------------+
 *   |
 *   |
 *   v
 * +-------------------+       +-------------------+      +-------------------+
 * |       TREE        |<----->|       TREE        |......|       TREE        |
 * +-------------------+       +-------------------+      +-------------------+
 *      |         |
 *      |         |
 *      |         v
 *      |     +-------+       +-------+      +-------+
 *      |     | OFILE |<----->| OFILE |......| OFILE |
 *      |     +-------+       +-------+      +-------+
 *      |
 *      |
 *      v
 *  +-------+       +------+      +------+
 *  | ODIR  |<----->| ODIR |......| ODIR |
 *  +-------+       +------+      +------+
 *
 *
 * User State Machine
 * ------------------
 *
 *
 *                  | T0:  Creation/Allocation
 *                  |      (1st session setup)
 *                  v
 *    +-----------------------------+
 *    |  SMB_USER_STATE_LOGGING_ON  |<----------+
 *    +-----------------------------+    addl. session setup
 *                  |           |       (more proc. required)
 *                  | T2        |               ^
 *                  |           |               | T1: (cont.)
 *                  |           +------->-------?
 *                  v                           | T3: (fail)
 *    +-----------------------------+           v
 *    |  SMB_USER_STATE_LOGGED_ON   |       (logged off)
 *    +-----------------------------+
 *                  |
 *                  | T4
 *                  |
 *                  v
 *    +-----------------------------+
 *    |  SMB_USER_STATE_LOGGING_OFF |
 *    +-----------------------------+
 *                  |
 *                  | T5
 *                  |
 *                  v
 *    +-----------------------------+    T6
 *    |  SMB_USER_STATE_LOGGED_OFF  |----------> Deletion/Free
 *    +-----------------------------+
 *
 * SMB_USER_STATE_LOGGING_ON
 *
 *    While in this state:
 *      - The user is in the list of users for their session.
 *      - References will be given out ONLY for session setup.
 *      - This user can not access anything yet.
 *
 * SMB_USER_STATE_LOGGED_ON
 *
 *    While in this state:
 *      - The user is in the list of users for their session.
 *      - References will be given out if the user is looked up.
 *      - The user can access files and pipes.
 *
 * SMB_USER_STATE_LOGGING_OFF
 *
 *    While in this state:
 *      - The user is in the list of users for their session.
 *      - References will not be given out if the user is looked up.
 *      - The trees the user connected are being disconnected.
 *      - The resources associated with the user remain.
 *
 * SMB_USER_STATE_LOGGED_OFF
 *
 *    While in this state:
 *      - The user is queued in the list of users of their session.
 *      - References will not be given out if the user is looked up.
 *      - The user has no more trees connected.
 *      - The resources associated with the user remain.
 *
 * Transition T0
 *
 *    First request in an SMB Session Setup sequence creates a
 *    new user object and adds it to the list of users for
 *    this session.  User UID is assigned and returned.
 *
 * Transition T1
 *
 *    Subsequent SMB Session Setup requests (on the same UID
 *    assigned in T0) update the state of this user object,
 *    communicating with smbd for the crypto work.
 *
 * Transition T2
 *
 *    If the SMB Session Setup sequence is successful, T2
 *    makes the new user object available for requests.
 *
 * Transition T3
 *
 *    If an Session Setup request gets an error other than
 *    the expected "more processing required", then T3
 *    leads to state "LOGGED_OFF" and then tear-down of the
 *    partially constructed user.
 *
 * Transition T4
 *
 *    Normal SMB User Logoff request, or session tear-down.
 *
 * Transition T5
 *
 *    This transition occurs in smb_user_release(). The resources associated
 *    with the user are deleted as well as the user. For the transition to
 *    occur, the user must be in the SMB_USER_STATE_LOGGED_OFF state and the
 *    reference count be zero.
 *
 * Comments
 * --------
 *
 *    The state machine of the user structures is controlled by 3 elements:
 *      - The list of users of the session they belong to.
 *      - The mutex embedded in the structure itself.
 *      - The reference count.
 *
 *    There's a mutex embedded in the user structure used to protect its fields
 *    and there's a lock embedded in the list of users of a session. To
 *    increment or to decrement the reference count the mutex must be entered.
 *    To insert the user into the list of users of the session and to remove
 *    the user from it, the lock must be entered in RW_WRITER mode.
 *
 *    Rules of access to a user structure:
 *
 *    1) In order to avoid deadlocks, when both (mutex and lock of the session
 *       list) have to be entered, the lock must be entered first. Additionally,
 *       one may NOT flush the deleteq of either the tree list or the ofile list
 *       while the user mutex is held.
 *
 *    2) All actions applied to a user require a reference count.
 *
 *    3) There are 2 ways of getting a reference count. One is when the user
 *       logs in. The other when the user is looked up.
 *
 *    It should be noted that the reference count of a user registers the
 *    number of references to the user in other structures (such as an smb
 *    request). The reference count is not incremented in these 2 instances:
 *
 *    1) The user is logged in. An user is anchored by their state. If there's
 *       no activity involving a user currently logged in, the reference
 *       count of that user is zero.
 *
 *    2) The user is queued in the list of users of the session. The fact of
 *       being queued in that list is NOT registered by incrementing the
 *       reference count.
 */
#include <sys/types.h>
#include <sys/sid.h>
#include <sys/priv_names.h>
#include <sys/priv.h>
#include <sys/policy.h>
#include <smbsrv/smb_kproto.h>
#include <smbsrv/smb_door.h>

#define ADMINISTRATORS_SID      "S-1-5-32-544"

/* Don't leak object addresses */
#define SMB_USER_SSNID(u) \
        ((uintptr_t)&smb_cache_user ^ (uintptr_t)(u))

static void smb_user_delete(void *);
static int smb_user_enum_private(smb_user_t *, smb_svcenum_t *);
static void smb_user_auth_logoff(smb_user_t *);
static void smb_user_logoff_tq(void *);

/*
 * Create a new user.
 *
 * For SMB2 and later, session IDs (u_ssnid) need to be unique among all
 * current and "recent" sessions.  The session ID is derived from the
 * address of the smb_user object (obscured by XOR with a constant).
 * This adds a 3-bit generation number in the low bits, incremented
 * when we allocate an smb_user_t from its kmem cache, so it can't
 * be confused with a (recent) previous incarnation of this object.
 */
smb_user_t *
smb_user_new(smb_session_t *session)
{
        smb_user_t      *user;
        uint_t          gen;    // generation (low 3 bits of ssnid)
        uint32_t        ucount;

        ASSERT(session);
        ASSERT(session->s_magic == SMB_SESSION_MAGIC);

        user = kmem_cache_alloc(smb_cache_user, KM_SLEEP);
        gen = (user->u_ssnid + 1) & 7;
        bzero(user, sizeof (smb_user_t));

        user->u_refcnt = 1;
        user->u_session = session;
        user->u_server = session->s_server;
        user->u_logon_time = gethrestime_sec();

        if (smb_idpool_alloc(&session->s_uid_pool, &user->u_uid))
                goto errout;
        user->u_ssnid = SMB_USER_SSNID(user) + gen;

        mutex_init(&user->u_mutex, NULL, MUTEX_DEFAULT, NULL);
        user->u_state = SMB_USER_STATE_LOGGING_ON;
        user->u_magic = SMB_USER_MAGIC;

        smb_llist_enter(&session->s_user_list, RW_WRITER);
        ucount = smb_llist_get_count(&session->s_user_list);
        smb_llist_insert_tail(&session->s_user_list, user);
        smb_llist_exit(&session->s_user_list);
        smb_server_inc_users(session->s_server);

        /*
         * If we added the first user to the session, cancel the
         * timeout that was started in smb_session_receiver().
         */
        if (ucount == 0) {
                timeout_id_t tmo = NULL;

                smb_rwx_rwenter(&session->s_lock, RW_WRITER);
                tmo = session->s_auth_tmo;
                session->s_auth_tmo = NULL;
                smb_rwx_rwexit(&session->s_lock);

                if (tmo != NULL)
                        (void) untimeout(tmo);
        }

        return (user);

errout:
        if (user->u_uid != 0)
                smb_idpool_free(&session->s_uid_pool, user->u_uid);
        kmem_cache_free(smb_cache_user, user);
        return (NULL);
}

/*
 * Fill in the details of a user, meaning a transition
 * from state LOGGING_ON to state LOGGED_ON.
 */
int
smb_user_logon(
    smb_user_t          *user,
    cred_t              *cr,
    char                *domain_name,
    char                *account_name,
    uint32_t            flags,
    uint32_t            privileges,
    uint32_t            audit_sid)
{
        ksocket_t authsock = NULL;
        timeout_id_t tmo = NULL;

        ASSERT(user->u_magic == SMB_USER_MAGIC);
        ASSERT(cr);
        ASSERT(account_name);
        ASSERT(domain_name);

        mutex_enter(&user->u_mutex);

        if (user->u_state != SMB_USER_STATE_LOGGING_ON) {
                mutex_exit(&user->u_mutex);
                return (-1);
        }

        /*
         * In the transition from LOGGING_ON to LOGGED_ON,
         * we always have an auth. socket to close.
         */
        authsock = user->u_authsock;
        user->u_authsock = NULL;
        tmo = user->u_auth_tmo;
        user->u_auth_tmo = NULL;

        user->u_state = SMB_USER_STATE_LOGGED_ON;
        user->u_flags = flags;
        user->u_name_len = strlen(account_name) + 1;
        user->u_domain_len = strlen(domain_name) + 1;
        user->u_name = smb_mem_strdup(account_name);
        user->u_domain = smb_mem_strdup(domain_name);
        user->u_audit_sid = audit_sid;

        smb_user_setcred(user, cr, privileges);

        mutex_exit(&user->u_mutex);

        /* Timeout callback takes u_mutex. See untimeout(9f) */
        if (tmo != NULL)
                (void) untimeout(tmo);

        /* This close can block, so not under the mutex. */
        if (authsock != NULL)
                smb_authsock_close(user, authsock);

        return (0);
}

/*
 * smb_user_logoff
 *
 * Change the user state to "logging off" and disconnect trees.
 * The user list must not be entered or modified here.
 *
 * We remain in state "logging off" until the last ref. is gone,
 * then smb_user_release takes us to state "logged off".
 */
void
smb_user_logoff(
    smb_user_t          *user)
{
        ksocket_t authsock = NULL;
        timeout_id_t tmo = NULL;

        ASSERT(user->u_magic == SMB_USER_MAGIC);

        mutex_enter(&user->u_mutex);
        ASSERT(user->u_refcnt);
        switch (user->u_state) {
        case SMB_USER_STATE_LOGGING_ON:
                authsock = user->u_authsock;
                user->u_authsock = NULL;
                tmo = user->u_auth_tmo;
                user->u_auth_tmo = NULL;
                user->u_state = SMB_USER_STATE_LOGGING_OFF;
                mutex_exit(&user->u_mutex);

                /* Timeout callback takes u_mutex. See untimeout(9f) */
                if (tmo != NULL)
                        (void) untimeout(tmo);
                /* This close can block, so not under the mutex. */
                if (authsock != NULL)
                        smb_authsock_close(user, authsock);
                break;

        case SMB_USER_STATE_LOGGED_ON:
                /*
                 * The user is moved into a state indicating that the log off
                 * process has started.
                 */
                user->u_state = SMB_USER_STATE_LOGGING_OFF;
                mutex_exit(&user->u_mutex);
                smb_session_disconnect_owned_trees(user->u_session, user);
                smb_user_auth_logoff(user);
                break;

        case SMB_USER_STATE_LOGGED_OFF:
        case SMB_USER_STATE_LOGGING_OFF:
                mutex_exit(&user->u_mutex);
                break;

        default:
                ASSERT(0);
                mutex_exit(&user->u_mutex);
                break;
        }
}

/*
 * Take a reference on a user.  Do not return a reference unless the user is in
 * the logged-in state.
 */
boolean_t
smb_user_hold(smb_user_t *user)
{
        SMB_USER_VALID(user);

        mutex_enter(&user->u_mutex);

        if (user->u_state == SMB_USER_STATE_LOGGED_ON) {
                user->u_refcnt++;
                mutex_exit(&user->u_mutex);
                return (B_TRUE);
        }

        mutex_exit(&user->u_mutex);
        return (B_FALSE);
}

/*
 * Unconditionally take a reference on a user.
 */
void
smb_user_hold_internal(smb_user_t *user)
{
        SMB_USER_VALID(user);

        mutex_enter(&user->u_mutex);
        user->u_refcnt++;
        mutex_exit(&user->u_mutex);
}

/*
 * Release a reference on a user.  If the reference count falls to
 * zero and the user has logged off, post the object for deletion.
 * Object deletion is deferred to avoid modifying a list while an
 * iteration may be in progress.
 */
void
smb_user_release(
    smb_user_t          *user)
{
        smb_session_t *ssn = user->u_session;

        SMB_USER_VALID(user);

        /* flush the tree list delete queue */
        smb_llist_flush(&ssn->s_tree_list);

        mutex_enter(&user->u_mutex);
        ASSERT(user->u_refcnt);
        user->u_refcnt--;

        switch (user->u_state) {
        case SMB_USER_STATE_LOGGING_OFF:
                if (user->u_refcnt == 0) {
                        smb_session_t *ssn = user->u_session;
                        user->u_state = SMB_USER_STATE_LOGGED_OFF;
                        smb_llist_post(&ssn->s_user_list, user,
                            smb_user_delete);
                }
                break;

        case SMB_USER_STATE_LOGGING_ON:
        case SMB_USER_STATE_LOGGED_ON:
                break;

        case SMB_USER_STATE_LOGGED_OFF:
        default:
                ASSERT(0);
                break;
        }
        mutex_exit(&user->u_mutex);
}

/*
 * Timeout handler for user logons that stay too long in
 * state SMB_USER_STATE_LOGGING_ON.  This is setup by a
 * timeout call in smb_authsock_open, and called in a
 * callout thread, so schedule a taskq job to do the
 * real work of logging off this user.
 */
void
smb_user_auth_tmo(void *arg)
{
        smb_user_t *user = arg;
        smb_request_t *sr;
        taskqid_t tqid;

        SMB_USER_VALID(user);

        /*
         * If we can't allocate a request, it means the
         * session is being torn down, so nothing to do.
         */
        sr = smb_request_alloc(user->u_session, 0);
        if (sr == NULL)
                return;

        /*
         * Check user state, and take a hold if it's
         * still logging on.  If not, we're done.
         */
        mutex_enter(&user->u_mutex);
        if (user->u_state != SMB_USER_STATE_LOGGING_ON) {
                mutex_exit(&user->u_mutex);
                smb_request_free(sr);
                return;
        }
        /* smb_user_hold_internal */
        user->u_refcnt++;
        mutex_exit(&user->u_mutex);

        /*
         * The user hold is given to the SR, and released in
         * smb_user_logoff_tq / smb_request_free
         */
        sr->uid_user = user;
        sr->user_cr = user->u_cred;
        sr->sr_state = SMB_REQ_STATE_SUBMITTED;
        tqid = taskq_dispatch(
            user->u_server->sv_worker_pool,
            smb_user_logoff_tq, sr, TQ_SLEEP);
        VERIFY(tqid != TASKQID_INVALID);
}

/*
 * Helper for smb_user_auth_tmo()
 */
static void
smb_user_logoff_tq(void *arg)
{
        smb_request_t   *sr = arg;

        SMB_REQ_VALID(sr);

        mutex_enter(&sr->sr_mutex);
        sr->sr_worker = curthread;
        sr->sr_state = SMB_REQ_STATE_ACTIVE;
        mutex_exit(&sr->sr_mutex);

        smb_user_logoff(sr->uid_user);

        sr->sr_state = SMB_REQ_STATE_COMPLETED;
        smb_request_free(sr);
}

/*
 * Determine whether or not the user is an administrator.
 * Members of the administrators group have administrative rights.
 */
boolean_t
smb_user_is_admin(smb_user_t *user)
{
#ifdef  _KERNEL
        char            sidstr[SMB_SID_STRSZ];
        ksidlist_t      *ksidlist;
        ksid_t          *ksid;
        uint32_t        rid;
        int             ret;
#endif  /* _KERNEL */
        boolean_t       rc = B_FALSE;

        ASSERT(user);
        ASSERT(user->u_cred);

        if (SMB_USER_IS_ADMIN(user))
                return (B_TRUE);

#ifdef  _KERNEL
        (void) strlcpy(sidstr, ADMINISTRATORS_SID, SMB_SID_STRSZ);
        ret = smb_sid_splitstr(sidstr, &rid);
        ASSERT3S(ret, ==, 0);

        ksidlist = crgetsidlist(user->u_cred);
        ASSERT(ksidlist);

        ksid = crgetsid(user->u_cred, KSID_USER);
        ASSERT(ksid != NULL);
        ASSERT(ksid->ks_domain != NULL);
        ASSERT(ksid->ks_domain->kd_name != NULL);

        if ((rid == ksid->ks_rid &&
            strcmp(sidstr, ksid_getdomain(ksid)) == 0) ||
            ksidlist_has_sid(ksidlist, sidstr, rid)) {
                user->u_flags |= SMB_USER_FLAG_ADMIN;
                rc = B_TRUE;
        }

#endif  /* _KERNEL */
        return (rc);
}

/*
 * This function should be called with a hold on the user.
 */
boolean_t
smb_user_namecmp(smb_user_t *user, const char *name)
{
        char            *fq_name;
        boolean_t       match;

        if (smb_strcasecmp(name, user->u_name, 0) == 0)
                return (B_TRUE);

        fq_name = kmem_alloc(MAXNAMELEN, KM_SLEEP);

        (void) snprintf(fq_name, MAXNAMELEN, "%s\\%s",
            user->u_domain, user->u_name);

        match = (smb_strcasecmp(name, fq_name, 0) == 0);
        if (!match) {
                (void) snprintf(fq_name, MAXNAMELEN, "%s@%s",
                    user->u_name, user->u_domain);

                match = (smb_strcasecmp(name, fq_name, 0) == 0);
        }

        kmem_free(fq_name, MAXNAMELEN);
        return (match);
}

/*
 * If the enumeration request is for user data, handle the request
 * here.  Otherwise, pass it on to the trees.
 *
 * This function should be called with a hold on the user.
 */
int
smb_user_enum(smb_user_t *user, smb_svcenum_t *svcenum)
{
        int             rc = 0;

        ASSERT(user);
        ASSERT(user->u_magic == SMB_USER_MAGIC);

        if (svcenum->se_type == SMB_SVCENUM_TYPE_USER)
                return (smb_user_enum_private(user, svcenum));

        return (rc);
}

/*
 * Count references by trees this user owns,
 * and allow waiting for them to go away.
 */
void
smb_user_inc_trees(smb_user_t *user)
{
        mutex_enter(&user->u_mutex);
        user->u_owned_tree_cnt++;
        mutex_exit(&user->u_mutex);
}

void
smb_user_dec_trees(smb_user_t *user)
{
        mutex_enter(&user->u_mutex);
        user->u_owned_tree_cnt--;
        if (user->u_owned_tree_cnt == 0)
                cv_broadcast(&user->u_owned_tree_cv);
        mutex_exit(&user->u_mutex);
}

int smb_user_wait_tree_tmo = 30;

/*
 * Wait (up to 30 sec.) for trees to go away.
 * Should happen in less than a second.
 */
void
smb_user_wait_trees(smb_user_t *user)
{
        clock_t time;

        time = SEC_TO_TICK(smb_user_wait_tree_tmo) + ddi_get_lbolt();
        mutex_enter(&user->u_mutex);
        while (user->u_owned_tree_cnt != 0) {
                if (cv_timedwait(&user->u_owned_tree_cv,
                    &user->u_mutex, time) < 0)
                        break;
        }
        mutex_exit(&user->u_mutex);
        if (user->u_owned_tree_cnt != 0) {
#ifdef  DEBUG
                cmn_err(CE_NOTE, "!smb_user_wait_trees failed");
#endif
                DTRACE_PROBE1(max__wait, smb_user_t *, user);
        }
}

/* *************************** Static Functions ***************************** */

/*
 * Delete a user.  The tree list should be empty.
 *
 * Remove the user from the session's user list before freeing resources
 * associated with the user.
 */
static void
smb_user_delete(void *arg)
{
        smb_session_t   *session;
        smb_user_t      *user = (smb_user_t *)arg;
        uint32_t        ucount;

        SMB_USER_VALID(user);
        ASSERT(user->u_refcnt == 0);
        ASSERT(user->u_state == SMB_USER_STATE_LOGGED_OFF);
        ASSERT(user->u_authsock == NULL);
        ASSERT(user->u_auth_tmo == NULL);

        session = user->u_session;

        smb_server_dec_users(session->s_server);
        smb_llist_enter(&session->s_user_list, RW_WRITER);
        smb_llist_remove(&session->s_user_list, user);
        smb_idpool_free(&session->s_uid_pool, user->u_uid);
        ucount = smb_llist_get_count(&session->s_user_list);
        smb_llist_exit(&session->s_user_list);

        /*
         * When the last smb_user_t object goes away, schedule a timeout
         * after which we'll terminate this session if the client hasn't
         * authenticated another smb_user_t on this session by then.
         */
        if (ucount == 0) {
                smb_rwx_rwenter(&session->s_lock, RW_WRITER);
                if (session->s_state == SMB_SESSION_STATE_NEGOTIATED &&
                    session->s_auth_tmo == NULL) {
                        session->s_auth_tmo =
                            timeout((tmo_func_t)smb_session_disconnect,
                            session, SEC_TO_TICK(smb_session_auth_tmo));
                }
                smb_rwx_cvbcast(&session->s_lock);
                smb_rwx_rwexit(&session->s_lock);
        }

        /*
         * This user is no longer on s_user_list, however...
         *
         * This is called via smb_llist_post, which means it may run
         * BEFORE smb_user_release drops u_mutex (if another thread
         * flushes the delete queue before we do).  Synchronize.
         */
        mutex_enter(&user->u_mutex);
        mutex_exit(&user->u_mutex);

        user->u_magic = (uint32_t)~SMB_USER_MAGIC;
        mutex_destroy(&user->u_mutex);
        if (user->u_cred)
                crfree(user->u_cred);
        if (user->u_privcred)
                crfree(user->u_privcred);
        smb_mem_free(user->u_name);
        smb_mem_free(user->u_domain);
        kmem_cache_free(smb_cache_user, user);
}

cred_t *
smb_user_getcred(smb_user_t *user)
{
        return (user->u_cred);
}

cred_t *
smb_user_getprivcred(smb_user_t *user)
{
        return ((user->u_privcred)? user->u_privcred : user->u_cred);
}

#ifdef  _KERNEL
/*
 * Assign the user cred and privileges.
 *
 * If the user has backup and/or restore privleges, dup the cred
 * and add those privileges to this new privileged cred.
 */
void
smb_user_setcred(smb_user_t *user, cred_t *cr, uint32_t privileges)
{
        cred_t *privcred = NULL;

        ASSERT(cr);
        crhold(cr);

        /*
         * See smb.4 bypass_traverse_checking
         *
         * For historical reasons, the Windows privilege is named
         * SeChangeNotifyPrivilege, though the description is
         * "Bypass traverse checking".
         */
        if ((privileges & SMB_USER_PRIV_CHANGE_NOTIFY) != 0) {
                (void) crsetpriv(cr, PRIV_FILE_DAC_SEARCH, NULL);
        }

        /*
         * Window's "take ownership privilege" is similar to our
         * PRIV_FILE_CHOWN privilege. It's normally given to members of the
         * "Administrators" group, which normally includes the the local
         * Administrator (like root) and when joined to a domain,
         * "Domain Admins".
         */
        if ((privileges & SMB_USER_PRIV_TAKE_OWNERSHIP) != 0) {
                (void) crsetpriv(cr,
                    PRIV_FILE_CHOWN,
                    PRIV_FILE_CHOWN_SELF,
                    NULL);
        }

        /*
         * Bypass ACL for READ accesses.
         */
        if ((privileges & SMB_USER_PRIV_READ_FILE) != 0) {
                (void) crsetpriv(cr, PRIV_FILE_DAC_READ, NULL);
        }

        /*
         * Bypass ACL for WRITE accesses.
         * Include FILE_OWNER, as it covers WRITE_ACL and DELETE.
         */
        if ((privileges & SMB_USER_PRIV_WRITE_FILE) != 0) {
                (void) crsetpriv(cr,
                    PRIV_FILE_DAC_WRITE,
                    PRIV_FILE_OWNER,
                    NULL);
        }

        /*
         * These privileges are used only when a file is opened with
         * 'backup intent'. These allow users to bypass certain access
         * controls. Administrators typically have these privileges,
         * and they are used during recursive take-ownership operations.
         * Some commonly used tools use 'backup intent' to administrate
         * files that do not grant explicit permissions to Administrators.
         */
        if (privileges & (SMB_USER_PRIV_BACKUP | SMB_USER_PRIV_RESTORE))
                privcred = crdup(cr);

        if (privcred != NULL) {
                if (privileges & SMB_USER_PRIV_BACKUP) {
                        (void) crsetpriv(privcred, PRIV_FILE_DAC_READ,
                            PRIV_FILE_DAC_SEARCH, PRIV_SYS_MOUNT, NULL);
                }

                if (privileges & SMB_USER_PRIV_RESTORE) {
                        (void) crsetpriv(privcred, PRIV_FILE_DAC_WRITE,
                            PRIV_FILE_CHOWN, PRIV_FILE_CHOWN_SELF,
                            PRIV_FILE_DAC_SEARCH, PRIV_FILE_LINK_ANY,
                            PRIV_FILE_OWNER, PRIV_FILE_SETID,
                            PRIV_SYS_LINKDIR, PRIV_SYS_MOUNT, NULL);
                }
        }

        user->u_cred = cr;
        user->u_privcred = privcred;
        user->u_privileges = privileges;
}
#endif  /* _KERNEL */

/*
 * Determines whether a user can be granted ACCESS_SYSTEM_SECURITY
 */
boolean_t
smb_user_has_security_priv(smb_user_t *user, cred_t *cr)
{
        /* Need SeSecurityPrivilege to get/set SACL */
        if ((user->u_privileges & SMB_USER_PRIV_SECURITY) != 0)
                return (B_TRUE);

#ifdef _KERNEL
        /*
         * ACCESS_SYSTEM_SECURITY is also granted if the file is opened with
         * BACKUP/RESTORE intent by a user with BACKUP/RESTORE privilege,
         * which means we'll be using u_privcred.
         *
         * We translate BACKUP as DAC_READ and RESTORE as DAC_WRITE,
         * to account for our various SMB_USER_* privileges.
         */
        if (PRIV_POLICY_ONLY(cr,
            priv_getbyname(PRIV_FILE_DAC_READ, 0), B_FALSE) ||
            PRIV_POLICY_ONLY(cr,
            priv_getbyname(PRIV_FILE_DAC_WRITE, 0), B_FALSE))
                return (B_TRUE);
#else
        /*
         * No "real" privileges in fksmbsrv, so use the SMB privs instead.
         */
        if ((user->u_privileges &
            (SMB_USER_PRIV_BACKUP |
            SMB_USER_PRIV_RESTORE |
            SMB_USER_PRIV_READ_FILE |
            SMB_USER_PRIV_WRITE_FILE)) != 0)
                return (B_TRUE);
#endif

        return (B_FALSE);
}

/*
 * Private function to support smb_user_enum.
 */
static int
smb_user_enum_private(smb_user_t *user, smb_svcenum_t *svcenum)
{
        uint8_t *pb;
        uint_t nbytes;
        int rc;

        if (svcenum->se_nskip > 0) {
                svcenum->se_nskip--;
                return (0);
        }

        if (svcenum->se_nitems >= svcenum->se_nlimit) {
                svcenum->se_nitems = svcenum->se_nlimit;
                return (0);
        }

        pb = &svcenum->se_buf[svcenum->se_bused];
        rc = smb_user_netinfo_encode(user, pb, svcenum->se_bavail, &nbytes);
        if (rc == 0) {
                svcenum->se_bavail -= nbytes;
                svcenum->se_bused += nbytes;
                svcenum->se_nitems++;
        }

        return (rc);
}

/*
 * Encode the NetInfo for a user into a buffer.  NetInfo contains
 * information that is often needed in user space to support RPC
 * requests.
 */
int
smb_user_netinfo_encode(smb_user_t *user, uint8_t *buf, size_t buflen,
    uint32_t *nbytes)
{
        smb_netuserinfo_t       info;
        int                     rc;

        smb_user_netinfo_init(user, &info);
        rc = smb_netuserinfo_encode(&info, buf, buflen, nbytes);
        smb_user_netinfo_fini(&info);

        return (rc);
}

void
smb_user_netinfo_init(smb_user_t *user, smb_netuserinfo_t *info)
{
        smb_session_t   *session;
        char            *buf;

        ASSERT(user);
        ASSERT(user->u_domain);
        ASSERT(user->u_name);

        session = user->u_session;
        ASSERT(session);
        ASSERT(session->workstation);

        info->ui_session_id = session->s_kid;
        info->ui_user_id = user->u_ssnid;
        info->ui_native_os = session->native_os;
        info->ui_ipaddr = session->ipaddr;
        info->ui_numopens = session->s_file_cnt;
        info->ui_logon_time = user->u_logon_time;
        info->ui_flags = user->u_flags;
        info->ui_posix_uid = crgetuid(user->u_cred);

        info->ui_domain_len = user->u_domain_len;
        info->ui_domain = smb_mem_strdup(user->u_domain);

        info->ui_account_len = user->u_name_len;
        info->ui_account = smb_mem_strdup(user->u_name);

        buf = kmem_alloc(MAXNAMELEN, KM_SLEEP);
        smb_session_getclient(session, buf, MAXNAMELEN);
        info->ui_workstation_len = strlen(buf) + 1;
        info->ui_workstation = smb_mem_strdup(buf);
        kmem_free(buf, MAXNAMELEN);
}

void
smb_user_netinfo_fini(smb_netuserinfo_t *info)
{
        if (info == NULL)
                return;

        if (info->ui_domain)
                smb_mem_free(info->ui_domain);
        if (info->ui_account)
                smb_mem_free(info->ui_account);
        if (info->ui_workstation)
                smb_mem_free(info->ui_workstation);

        bzero(info, sizeof (smb_netuserinfo_t));
}

uint64_t smb_user_auth_logoff_failures;

/*
 * Tell smbd this user is going away so it can clean up their
 * audit session, autohome dir, etc.
 *
 * Note that when we're shutting down, smbd will already have set
 * smbd.s_shutting_down and therefore will ignore door calls.
 * Skip this during shutdown to reduce upcall noise.
 */
static void
smb_user_auth_logoff(smb_user_t *user)
{
        smb_server_t *sv = user->u_server;
        uint32_t audit_sid;

        if (sv->sv_state != SMB_SERVER_STATE_RUNNING)
                return;

        if (smb_threshold_enter(&sv->sv_logoff_ct) != 0) {
                smb_user_auth_logoff_failures++;
                return;
        }

        audit_sid = user->u_audit_sid;
        (void) smb_kdoor_upcall(sv, SMB_DR_USER_AUTH_LOGOFF,
            &audit_sid, xdr_uint32_t, NULL, NULL);

        smb_threshold_exit(&sv->sv_logoff_ct);
}

boolean_t
smb_is_same_user(cred_t *cr1, cred_t *cr2)
{
        ksid_t *ks1 = crgetsid(cr1, KSID_USER);
        ksid_t *ks2 = crgetsid(cr2, KSID_USER);

        if (ks1 == NULL || ks2 == NULL) {
                return (B_FALSE);
        }
        return (ks1->ks_rid == ks2->ks_rid &&
            strcmp(ks1->ks_domain->kd_name, ks2->ks_domain->kd_name) == 0);
}