5917 User-mode SMB server

[unleashed.git] / usr / src / uts / common / fs / smbsrv / smb_kshare.c

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

/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
 */

#include <smbsrv/smb_door.h>
#include <smbsrv/smb_kproto.h>
#include <smbsrv/smb_ktypes.h>

typedef struct smb_unshare {
        list_node_t     us_lnd;
        char            us_sharename[MAXNAMELEN];
} smb_unshare_t;

static kmem_cache_t     *smb_kshare_cache_share;
static kmem_cache_t     *smb_kshare_cache_unexport;
kmem_cache_t    *smb_kshare_cache_vfs;

static int smb_kshare_cmp(const void *, const void *);
static void smb_kshare_hold(const void *);
static boolean_t smb_kshare_rele(const void *);
static void smb_kshare_destroy(void *);
static char *smb_kshare_oemname(const char *);
static int smb_kshare_is_special(const char *);
static boolean_t smb_kshare_is_admin(const char *);
static smb_kshare_t *smb_kshare_decode(nvlist_t *);
static uint32_t smb_kshare_decode_bool(nvlist_t *, const char *, uint32_t);
static void smb_kshare_unexport_thread(smb_thread_t *, void *);
static int smb_kshare_export(smb_server_t *, smb_kshare_t *);
static int smb_kshare_unexport(smb_server_t *, const char *);
static int smb_kshare_export_trans(smb_server_t *, char *, char *, char *);
static void smb_kshare_csc_flags(smb_kshare_t *, const char *);

static boolean_t smb_export_isready(smb_server_t *);

#ifdef  _KERNEL
static int smb_kshare_chk_dsrv_status(int, smb_dr_ctx_t *);
#endif  /* _KERNEL */

static const smb_avl_nops_t smb_kshare_avlops = {
        smb_kshare_cmp,
        smb_kshare_hold,
        smb_kshare_rele,
        smb_kshare_destroy
};

#ifdef  _KERNEL
/*
 * This function is not MultiThread safe. The caller has to make sure only one
 * thread calls this function.
 */
door_handle_t
smb_kshare_door_init(int door_id)
{
        return (door_ki_lookup(door_id));
}

/*
 * This function is not MultiThread safe. The caller has to make sure only one
 * thread calls this function.
 */
void
smb_kshare_door_fini(door_handle_t dhdl)
{
        if (dhdl)
                door_ki_rele(dhdl);
}

/*
 * This is a special interface that will be utilized by ZFS to cause
 * a share to be added/removed
 *
 * arg is either a smb_share_t or share_name from userspace.
 * It will need to be copied into the kernel.   It is smb_share_t
 * for add operations and share_name for delete operations.
 */
int
smb_kshare_upcall(door_handle_t dhdl, void *arg, boolean_t add_share)
{
        door_arg_t      doorarg = { 0 };
        char            *buf = NULL;
        char            *str = NULL;
        int             error;
        int             rc;
        unsigned int    used;
        smb_dr_ctx_t    *dec_ctx;
        smb_dr_ctx_t    *enc_ctx;
        smb_share_t     *lmshare = NULL;
        int             opcode;

        opcode = (add_share) ? SMB_SHROP_ADD : SMB_SHROP_DELETE;

        buf = kmem_alloc(SMB_SHARE_DSIZE, KM_SLEEP);
        enc_ctx = smb_dr_encode_start(buf, SMB_SHARE_DSIZE);
        smb_dr_put_uint32(enc_ctx, opcode);

        switch (opcode) {
        case SMB_SHROP_ADD:
                lmshare = kmem_alloc(sizeof (smb_share_t), KM_SLEEP);
                error = xcopyin(arg, lmshare, sizeof (smb_share_t));
                if (error != 0) {
                        kmem_free(lmshare, sizeof (smb_share_t));
                        kmem_free(buf, SMB_SHARE_DSIZE);
                        return (error);
                }
                smb_dr_put_share(enc_ctx, lmshare);
                break;

        case SMB_SHROP_DELETE:
                str = kmem_alloc(MAXPATHLEN, KM_SLEEP);
                error = copyinstr(arg, str, MAXPATHLEN, NULL);
                if (error != 0) {
                        kmem_free(str, MAXPATHLEN);
                        kmem_free(buf, SMB_SHARE_DSIZE);
                        return (error);
                }
                smb_dr_put_string(enc_ctx, str);
                kmem_free(str, MAXPATHLEN);
                break;
        }

        if ((error = smb_dr_encode_finish(enc_ctx, &used)) != 0) {
                kmem_free(buf, SMB_SHARE_DSIZE);
                if (lmshare)
                        kmem_free(lmshare, sizeof (smb_share_t));
                return (NERR_InternalError);
        }

        doorarg.data_ptr = buf;
        doorarg.data_size = used;
        doorarg.rbuf = buf;
        doorarg.rsize = SMB_SHARE_DSIZE;

        error = door_ki_upcall_limited(dhdl, &doorarg, NULL, SIZE_MAX, 0);

        if (error) {
                kmem_free(buf, SMB_SHARE_DSIZE);
                if (lmshare)
                        kmem_free(lmshare, sizeof (smb_share_t));
                return (error);
        }

        dec_ctx = smb_dr_decode_start(doorarg.data_ptr, doorarg.data_size);
        if (smb_kshare_chk_dsrv_status(opcode, dec_ctx) != 0) {
                kmem_free(buf, SMB_SHARE_DSIZE);
                if (lmshare)
                        kmem_free(lmshare, sizeof (smb_share_t));
                return (NERR_InternalError);
        }

        rc = smb_dr_get_uint32(dec_ctx);
        if (opcode == SMB_SHROP_ADD)
                smb_dr_get_share(dec_ctx, lmshare);

        if (smb_dr_decode_finish(dec_ctx))
                rc = NERR_InternalError;

        kmem_free(buf, SMB_SHARE_DSIZE);
        if (lmshare)
                kmem_free(lmshare, sizeof (smb_share_t));

        return ((rc == NERR_DuplicateShare && add_share) ? 0 : rc);
}
#endif  /* _KERNEL */

/*
 * Executes map and unmap command for shares.
 */
int
smb_kshare_exec(smb_server_t *sv, smb_shr_execinfo_t *execinfo)
{
        int exec_rc = 0;

        (void) smb_kdoor_upcall(sv, SMB_DR_SHR_EXEC,
            execinfo, smb_shr_execinfo_xdr, &exec_rc, xdr_int);

        return (exec_rc);
}

/*
 * Obtains any host access restriction on the specified
 * share for the given host (ipaddr) by calling smbd
 */
uint32_t
smb_kshare_hostaccess(smb_kshare_t *shr, smb_session_t *session)
{
        smb_shr_hostaccess_query_t req;
        smb_inaddr_t *ipaddr = &session->ipaddr;
        uint32_t host_access = SMB_SHRF_ACC_OPEN;
        uint32_t flag = SMB_SHRF_ACC_OPEN;
        uint32_t access;

        if (smb_inet_iszero(ipaddr))
                return (ACE_ALL_PERMS);

        if ((shr->shr_access_none == NULL || *shr->shr_access_none == '\0') &&
            (shr->shr_access_ro == NULL || *shr->shr_access_ro == '\0') &&
            (shr->shr_access_rw == NULL || *shr->shr_access_rw == '\0'))
                return (ACE_ALL_PERMS);

        if (shr->shr_access_none != NULL)
                flag |= SMB_SHRF_ACC_NONE;
        if (shr->shr_access_ro != NULL)
                flag |= SMB_SHRF_ACC_RO;
        if (shr->shr_access_rw != NULL)
                flag |= SMB_SHRF_ACC_RW;

        req.shq_none = shr->shr_access_none;
        req.shq_ro = shr->shr_access_ro;
        req.shq_rw = shr->shr_access_rw;
        req.shq_flag = flag;
        req.shq_ipaddr = *ipaddr;

        (void) smb_kdoor_upcall(session->s_server, SMB_DR_SHR_HOSTACCESS,
            &req, smb_shr_hostaccess_query_xdr, &host_access, xdr_uint32_t);

        switch (host_access) {
        case SMB_SHRF_ACC_RO:
                access = ACE_ALL_PERMS & ~ACE_ALL_WRITE_PERMS;
                break;
        case SMB_SHRF_ACC_OPEN:
        case SMB_SHRF_ACC_RW:
                access = ACE_ALL_PERMS;
                break;
        case SMB_SHRF_ACC_NONE:
        default:
                access = 0;
        }

        return (access);
}

/*
 * This function is called when smb_server_t is
 * created which means smb/service is ready for
 * exporting SMB shares
 */
void
smb_export_start(smb_server_t *sv)
{
        mutex_enter(&sv->sv_export.e_mutex);
        if (sv->sv_export.e_ready) {
                mutex_exit(&sv->sv_export.e_mutex);
                return;
        }

        sv->sv_export.e_ready = B_TRUE;
        mutex_exit(&sv->sv_export.e_mutex);

        smb_avl_create(&sv->sv_export.e_share_avl, sizeof (smb_kshare_t),
            offsetof(smb_kshare_t, shr_link), &smb_kshare_avlops);

        (void) smb_kshare_export_trans(sv, "IPC$", "IPC$", "Remote IPC");
        (void) smb_kshare_export_trans(sv, "c$", SMB_CVOL, "Default Share");
        (void) smb_kshare_export_trans(sv, "vss$", SMB_VSS, "VSS");
}

/*
 * This function is called when smb_server_t goes
 * away which means SMB shares should not be made
 * available to clients
 */
void
smb_export_stop(smb_server_t *sv)
{
        mutex_enter(&sv->sv_export.e_mutex);
        if (!sv->sv_export.e_ready) {
                mutex_exit(&sv->sv_export.e_mutex);
                return;
        }
        sv->sv_export.e_ready = B_FALSE;
        mutex_exit(&sv->sv_export.e_mutex);

        smb_avl_destroy(&sv->sv_export.e_share_avl);
        smb_vfs_rele_all(&sv->sv_export);
}

void
smb_kshare_g_init(void)
{
        smb_kshare_cache_share = kmem_cache_create("smb_share_cache",
            sizeof (smb_kshare_t), 8, NULL, NULL, NULL, NULL, NULL, 0);

        smb_kshare_cache_unexport = kmem_cache_create("smb_unexport_cache",
            sizeof (smb_unshare_t), 8, NULL, NULL, NULL, NULL, NULL, 0);

        smb_kshare_cache_vfs = kmem_cache_create("smb_vfs_cache",
            sizeof (smb_vfs_t), 8, NULL, NULL, NULL, NULL, NULL, 0);
}

void
smb_kshare_init(smb_server_t *sv)
{

        smb_llist_constructor(&sv->sv_export.e_vfs_list, sizeof (smb_vfs_t),
            offsetof(smb_vfs_t, sv_lnd));

        smb_slist_constructor(&sv->sv_export.e_unexport_list,
            sizeof (smb_unshare_t), offsetof(smb_unshare_t, us_lnd));
}

int
smb_kshare_start(smb_server_t *sv)
{
        smb_thread_init(&sv->sv_export.e_unexport_thread, "smb_thread_unexport",
            smb_kshare_unexport_thread, sv, smbsrv_base_pri);

        return (smb_thread_start(&sv->sv_export.e_unexport_thread));
}

void
smb_kshare_stop(smb_server_t *sv)
{
        smb_thread_stop(&sv->sv_export.e_unexport_thread);
        smb_thread_destroy(&sv->sv_export.e_unexport_thread);
}

void
smb_kshare_fini(smb_server_t *sv)
{
        smb_unshare_t *ux;

        while ((ux = list_head(&sv->sv_export.e_unexport_list.sl_list))
            != NULL) {
                smb_slist_remove(&sv->sv_export.e_unexport_list, ux);
                kmem_cache_free(smb_kshare_cache_unexport, ux);
        }
        smb_slist_destructor(&sv->sv_export.e_unexport_list);

        smb_vfs_rele_all(&sv->sv_export);

        smb_llist_destructor(&sv->sv_export.e_vfs_list);
}

void
smb_kshare_g_fini(void)
{
        kmem_cache_destroy(smb_kshare_cache_unexport);
        kmem_cache_destroy(smb_kshare_cache_share);
        kmem_cache_destroy(smb_kshare_cache_vfs);
}

/*
 * A list of shares in nvlist format can be sent down
 * from userspace thourgh the IOCTL interface. The nvlist
 * is unpacked here and all the shares in the list will
 * be exported.
 */
int
smb_kshare_export_list(smb_ioc_share_t *ioc)
{
        smb_server_t    *sv = NULL;
        nvlist_t        *shrlist = NULL;
        nvlist_t         *share;
        nvpair_t         *nvp;
        smb_kshare_t     *shr;
        char            *shrname;
        int             rc;

        if ((rc = smb_server_lookup(&sv)) != 0)
                return (rc);

        if (!smb_export_isready(sv)) {
                rc = ENOTACTIVE;
                goto out;
        }

        rc = nvlist_unpack(ioc->shr, ioc->shrlen, &shrlist, KM_SLEEP);
        if (rc != 0)
                goto out;

        for (nvp = nvlist_next_nvpair(shrlist, NULL); nvp != NULL;
            nvp = nvlist_next_nvpair(shrlist, nvp)) {

                /*
                 * Since this loop can run for a while we want to exit
                 * as soon as the server state is anything but RUNNING
                 * to allow shutdown to proceed.
                 */
                if (sv->sv_state != SMB_SERVER_STATE_RUNNING)
                        goto out;

                if (nvpair_type(nvp) != DATA_TYPE_NVLIST)
                        continue;

                shrname = nvpair_name(nvp);
                ASSERT(shrname);

                if ((rc = nvpair_value_nvlist(nvp, &share)) != 0) {
                        cmn_err(CE_WARN, "export[%s]: failed accessing",
                            shrname);
                        continue;
                }

                if ((shr = smb_kshare_decode(share)) == NULL) {
                        cmn_err(CE_WARN, "export[%s]: failed decoding",
                            shrname);
                        continue;
                }

                /* smb_kshare_export consumes shr so it's not leaked */
                if ((rc = smb_kshare_export(sv, shr)) != 0) {
                        smb_kshare_destroy(shr);
                        continue;
                }
        }
        rc = 0;

out:
        if (shrlist != NULL)
                nvlist_free(shrlist);
        smb_server_release(sv);
        return (rc);
}

/*
 * This function is invoked when a share is disabled to disconnect trees
 * and close files.  Cleaning up may involve VOP and/or VFS calls, which
 * may conflict/deadlock with stuck threads if something is amiss with the
 * file system.  Queueing the request for asynchronous processing allows the
 * call to return immediately so that, if the unshare is being done in the
 * context of a forced unmount, the forced unmount will always be able to
 * proceed (unblocking stuck I/O and eventually allowing all blocked unshare
 * processes to complete).
 *
 * The path lookup to find the root vnode of the VFS in question and the
 * release of this vnode are done synchronously prior to any associated
 * unmount.  Doing these asynchronous to an associated unmount could run
 * the risk of a spurious EBUSY for a standard unmount or an EIO during
 * the path lookup due to a forced unmount finishing first.
 */
int
smb_kshare_unexport_list(smb_ioc_share_t *ioc)
{
        smb_server_t    *sv = NULL;
        smb_unshare_t   *ux;
        nvlist_t        *shrlist = NULL;
        nvpair_t        *nvp;
        boolean_t       unexport = B_FALSE;
        char            *shrname;
        int             rc;

        if ((rc = smb_server_lookup(&sv)) != 0)
                return (rc);

        if ((rc = nvlist_unpack(ioc->shr, ioc->shrlen, &shrlist, 0)) != 0)
                goto out;

        for (nvp = nvlist_next_nvpair(shrlist, NULL); nvp != NULL;
            nvp = nvlist_next_nvpair(shrlist, nvp)) {
                if (nvpair_type(nvp) != DATA_TYPE_NVLIST)
                        continue;

                shrname = nvpair_name(nvp);
                ASSERT(shrname);

                if ((rc = smb_kshare_unexport(sv, shrname)) != 0)
                        continue;

                ux = kmem_cache_alloc(smb_kshare_cache_unexport, KM_SLEEP);
                (void) strlcpy(ux->us_sharename, shrname, MAXNAMELEN);

                smb_slist_insert_tail(&sv->sv_export.e_unexport_list, ux);
                unexport = B_TRUE;
        }

        if (unexport)
                smb_thread_signal(&sv->sv_export.e_unexport_thread);
        rc = 0;

out:
        if (shrlist != NULL)
                nvlist_free(shrlist);
        smb_server_release(sv);
        return (rc);
}

/*
 * Get properties (currently only shortname enablement)
 * of specified share.
 */
int
smb_kshare_info(smb_ioc_shareinfo_t *ioc)
{
        ioc->shortnames = smb_shortnames;
        return (0);
}

/*
 * This function builds a response for a NetShareEnum RAP request.
 * List of shares is scanned twice. In the first round the total number
 * of shares which their OEM name is shorter than 13 chars (esi->es_ntotal)
 * and also the number of shares that fit in the given buffer are calculated.
 * In the second round the shares data are encoded in the buffer.
 *
 * The data associated with each share has two parts, a fixed size part and
 * a variable size part which is share's comment. The outline of the response
 * buffer is so that fixed part for all the shares will appear first and follows
 * with the comments for all those shares and that's why the data cannot be
 * encoded in one round without unnecessarily complicating the code.
 */
void
smb_kshare_enum(smb_server_t *sv, smb_enumshare_info_t *esi)
{
        smb_avl_t *share_avl;
        smb_avl_cursor_t cursor;
        smb_kshare_t *shr;
        int remained;
        uint16_t infolen = 0;
        uint16_t cmntlen = 0;
        uint16_t sharelen;
        uint16_t clen;
        uint32_t cmnt_offs;
        smb_msgbuf_t info_mb;
        smb_msgbuf_t cmnt_mb;
        boolean_t autohome_added = B_FALSE;

        if (!smb_export_isready(sv)) {
                esi->es_ntotal = esi->es_nsent = 0;
                esi->es_datasize = 0;
                return;
        }

        esi->es_ntotal = esi->es_nsent = 0;
        remained = esi->es_bufsize;
        share_avl = &sv->sv_export.e_share_avl;

        /* Do the necessary calculations in the first round */
        smb_avl_iterinit(share_avl, &cursor);

        while ((shr = smb_avl_iterate(share_avl, &cursor)) != NULL) {
                if (shr->shr_oemname == NULL) {
                        smb_avl_release(share_avl, shr);
                        continue;
                }

                if ((shr->shr_flags & SMB_SHRF_AUTOHOME) && !autohome_added) {
                        if (esi->es_posix_uid == shr->shr_uid) {
                                autohome_added = B_TRUE;
                        } else {
                                smb_avl_release(share_avl, shr);
                                continue;
                        }
                }

                esi->es_ntotal++;

                if (remained <= 0) {
                        smb_avl_release(share_avl, shr);
                        continue;
                }

                clen = strlen(shr->shr_cmnt) + 1;
                sharelen = SHARE_INFO_1_SIZE + clen;

                if (sharelen <= remained) {
                        infolen += SHARE_INFO_1_SIZE;
                        cmntlen += clen;
                }

                remained -= sharelen;
                smb_avl_release(share_avl, shr);
        }

        esi->es_datasize = infolen + cmntlen;

        smb_msgbuf_init(&info_mb, (uint8_t *)esi->es_buf, infolen, 0);
        smb_msgbuf_init(&cmnt_mb, (uint8_t *)esi->es_buf + infolen, cmntlen, 0);
        cmnt_offs = infolen;

        /* Encode the data in the second round */
        smb_avl_iterinit(share_avl, &cursor);
        autohome_added = B_FALSE;

        while ((shr = smb_avl_iterate(share_avl, &cursor)) != NULL) {
                if (shr->shr_oemname == NULL) {
                        smb_avl_release(share_avl, shr);
                        continue;
                }

                if ((shr->shr_flags & SMB_SHRF_AUTOHOME) && !autohome_added) {
                        if (esi->es_posix_uid == shr->shr_uid) {
                                autohome_added = B_TRUE;
                        } else {
                                smb_avl_release(share_avl, shr);
                                continue;
                        }
                }

                if (smb_msgbuf_encode(&info_mb, "13c.wl",
                    shr->shr_oemname, shr->shr_type, cmnt_offs) < 0) {
                        smb_avl_release(share_avl, shr);
                        break;
                }

                if (smb_msgbuf_encode(&cmnt_mb, "s", shr->shr_cmnt) < 0) {
                        smb_avl_release(share_avl, shr);
                        break;
                }

                cmnt_offs += strlen(shr->shr_cmnt) + 1;
                esi->es_nsent++;

                smb_avl_release(share_avl, shr);
        }

        smb_msgbuf_term(&info_mb);
        smb_msgbuf_term(&cmnt_mb);
}

/*
 * Looks up the given share and returns a pointer
 * to its definition if it's found. A hold on the
 * object is taken before the pointer is returned
 * in which case the caller MUST always call
 * smb_kshare_release().
 */
smb_kshare_t *
smb_kshare_lookup(smb_server_t *sv, const char *shrname)
{
        smb_kshare_t key;
        smb_kshare_t *shr;

        ASSERT(shrname);

        if (!smb_export_isready(sv))
                return (NULL);

        key.shr_name = (char *)shrname;
        shr = smb_avl_lookup(&sv->sv_export.e_share_avl, &key);
        return (shr);
}

/*
 * Releases the hold taken on the specified share object
 */
void
smb_kshare_release(smb_server_t *sv, smb_kshare_t *shr)
{
        ASSERT(shr);
        ASSERT(shr->shr_magic == SMB_SHARE_MAGIC);

        smb_avl_release(&sv->sv_export.e_share_avl, shr);
}

/*
 * Add the given share in the specified server.
 * If the share is a disk share, smb_vfs_hold() is
 * invoked to ensure that there is a hold on the
 * corresponding file system before the share is
 * added to shares AVL.
 *
 * If the share is an Autohome share and it is
 * already in the AVL only a reference count for
 * that share is incremented.
 */
static int
smb_kshare_export(smb_server_t *sv, smb_kshare_t *shr)
{
        smb_avl_t       *share_avl;
        smb_kshare_t    *auto_shr;
        vnode_t         *vp;
        int             rc = 0;

        share_avl = &sv->sv_export.e_share_avl;

        if (!STYPE_ISDSK(shr->shr_type)) {
                if ((rc = smb_avl_add(share_avl, shr)) != 0) {
                        cmn_err(CE_WARN, "export[%s]: failed caching (%d)",
                            shr->shr_name, rc);
                }

                return (rc);
        }

        if ((auto_shr = smb_avl_lookup(share_avl, shr)) != NULL) {
                if ((auto_shr->shr_flags & SMB_SHRF_AUTOHOME) == 0) {
                        smb_avl_release(share_avl, auto_shr);
                        return (EEXIST);
                }

                mutex_enter(&auto_shr->shr_mutex);
                auto_shr->shr_autocnt++;
                mutex_exit(&auto_shr->shr_mutex);
                smb_avl_release(share_avl, auto_shr);
                return (0);
        }

        if ((rc = smb_server_sharevp(sv, shr->shr_path, &vp)) != 0) {
                cmn_err(CE_WARN, "export[%s(%s)]: failed obtaining vnode (%d)",
                    shr->shr_name, shr->shr_path, rc);
                return (rc);
        }

        if ((rc = smb_vfs_hold(&sv->sv_export, vp->v_vfsp)) == 0) {
                if ((rc = smb_avl_add(share_avl, shr)) != 0) {
                        cmn_err(CE_WARN, "export[%s]: failed caching (%d)",
                            shr->shr_name, rc);
                        smb_vfs_rele(&sv->sv_export, vp->v_vfsp);
                }
        } else {
                cmn_err(CE_WARN, "export[%s(%s)]: failed holding VFS (%d)",
                    shr->shr_name, shr->shr_path, rc);
        }

        VN_RELE(vp);
        return (rc);
}

/*
 * Removes the share specified by 'shrname' from the AVL
 * tree of the given server if it's there.
 *
 * If the share is an Autohome share, the autohome count
 * is decremented and the share is only removed if the
 * count goes to zero.
 *
 * If the share is a disk share, the hold on the corresponding
 * file system is released before removing the share from
 * the AVL tree.
 */
static int
smb_kshare_unexport(smb_server_t *sv, const char *shrname)
{
        smb_avl_t       *share_avl;
        smb_kshare_t    key;
        smb_kshare_t    *shr;
        vnode_t         *vp;
        int             rc;
        boolean_t       auto_unexport;

        share_avl = &sv->sv_export.e_share_avl;

        key.shr_name = (char *)shrname;
        if ((shr = smb_avl_lookup(share_avl, &key)) == NULL)
                return (ENOENT);

        if ((shr->shr_flags & SMB_SHRF_AUTOHOME) != 0) {
                mutex_enter(&shr->shr_mutex);
                shr->shr_autocnt--;
                auto_unexport = (shr->shr_autocnt == 0);
                mutex_exit(&shr->shr_mutex);
                if (!auto_unexport) {
                        smb_avl_release(share_avl, shr);
                        return (0);
                }
        }

        if (STYPE_ISDSK(shr->shr_type)) {
                if ((rc = smb_server_sharevp(sv, shr->shr_path, &vp)) != 0) {
                        smb_avl_release(share_avl, shr);
                        cmn_err(CE_WARN, "unexport[%s]: failed obtaining vnode"
                            " (%d)", shrname, rc);
                        return (rc);
                }

                smb_vfs_rele(&sv->sv_export, vp->v_vfsp);
                VN_RELE(vp);
        }

        smb_avl_remove(share_avl, shr);
        smb_avl_release(share_avl, shr);

        return (0);
}

/*
 * Exports IPC$ or Admin shares
 */
static int
smb_kshare_export_trans(smb_server_t *sv, char *name, char *path, char *cmnt)
{
        smb_kshare_t *shr;

        ASSERT(name);
        ASSERT(path);

        shr = kmem_cache_alloc(smb_kshare_cache_share, KM_SLEEP);
        bzero(shr, sizeof (smb_kshare_t));

        shr->shr_magic = SMB_SHARE_MAGIC;
        shr->shr_refcnt = 1;
        shr->shr_flags = SMB_SHRF_TRANS | smb_kshare_is_admin(shr->shr_name);
        if (strcasecmp(name, "IPC$") == 0)
                shr->shr_type = STYPE_IPC;
        else
                shr->shr_type = STYPE_DISKTREE;

        shr->shr_type |= smb_kshare_is_special(shr->shr_name);

        shr->shr_name = smb_mem_strdup(name);
        if (path)
                shr->shr_path = smb_mem_strdup(path);
        if (cmnt)
                shr->shr_cmnt = smb_mem_strdup(cmnt);
        shr->shr_oemname = smb_kshare_oemname(name);

        return (smb_kshare_export(sv, shr));
}

/*
 * Decodes share information in an nvlist format into a smb_kshare_t
 * structure.
 *
 * This is a temporary function and will be replaced by functions
 * provided by libsharev2 code after it's available.
 */
static smb_kshare_t *
smb_kshare_decode(nvlist_t *share)
{
        smb_kshare_t tmp;
        smb_kshare_t *shr;
        nvlist_t *smb;
        char *csc_name = NULL;
        int rc;

        ASSERT(share);

        bzero(&tmp, sizeof (smb_kshare_t));

        rc = nvlist_lookup_string(share, "name", &tmp.shr_name);
        rc |= nvlist_lookup_string(share, "path", &tmp.shr_path);
        (void) nvlist_lookup_string(share, "desc", &tmp.shr_cmnt);

        ASSERT(tmp.shr_name && tmp.shr_path);

        rc |= nvlist_lookup_nvlist(share, "smb", &smb);
        if (rc != 0) {
                cmn_err(CE_WARN, "kshare: failed looking up SMB properties"
                    " (%d)", rc);
                return (NULL);
        }

        rc = nvlist_lookup_uint32(smb, "type", &tmp.shr_type);
        if (rc != 0) {
                cmn_err(CE_WARN, "kshare[%s]: failed getting the share type"
                    " (%d)", tmp.shr_name, rc);
                return (NULL);
        }

        (void) nvlist_lookup_string(smb, SHOPT_AD_CONTAINER,
            &tmp.shr_container);
        (void) nvlist_lookup_string(smb, SHOPT_NONE, &tmp.shr_access_none);
        (void) nvlist_lookup_string(smb, SHOPT_RO, &tmp.shr_access_ro);
        (void) nvlist_lookup_string(smb, SHOPT_RW, &tmp.shr_access_rw);

        tmp.shr_flags |= smb_kshare_decode_bool(smb, SHOPT_ABE, SMB_SHRF_ABE);
        tmp.shr_flags |= smb_kshare_decode_bool(smb, SHOPT_CATIA,
            SMB_SHRF_CATIA);
        tmp.shr_flags |= smb_kshare_decode_bool(smb, SHOPT_GUEST,
            SMB_SHRF_GUEST_OK);
        tmp.shr_flags |= smb_kshare_decode_bool(smb, SHOPT_DFSROOT,
            SMB_SHRF_DFSROOT);
        tmp.shr_flags |= smb_kshare_decode_bool(smb, "Autohome",
            SMB_SHRF_AUTOHOME);

        if ((tmp.shr_flags & SMB_SHRF_AUTOHOME) == SMB_SHRF_AUTOHOME) {
                rc = nvlist_lookup_uint32(smb, "uid", &tmp.shr_uid);
                rc |= nvlist_lookup_uint32(smb, "gid", &tmp.shr_gid);
                if (rc != 0) {
                        cmn_err(CE_WARN, "kshare: failed looking up uid/gid"
                            " (%d)", rc);
                        return (NULL);
                }
        }

        (void) nvlist_lookup_string(smb, SHOPT_CSC, &csc_name);
        smb_kshare_csc_flags(&tmp, csc_name);

        shr = kmem_cache_alloc(smb_kshare_cache_share, KM_SLEEP);
        bzero(shr, sizeof (smb_kshare_t));

        shr->shr_magic = SMB_SHARE_MAGIC;
        shr->shr_refcnt = 1;

        shr->shr_name = smb_mem_strdup(tmp.shr_name);
        shr->shr_path = smb_mem_strdup(tmp.shr_path);
        if (tmp.shr_cmnt)
                shr->shr_cmnt = smb_mem_strdup(tmp.shr_cmnt);
        if (tmp.shr_container)
                shr->shr_container = smb_mem_strdup(tmp.shr_container);
        if (tmp.shr_access_none)
                shr->shr_access_none = smb_mem_strdup(tmp.shr_access_none);
        if (tmp.shr_access_ro)
                shr->shr_access_ro = smb_mem_strdup(tmp.shr_access_ro);
        if (tmp.shr_access_rw)
                shr->shr_access_rw = smb_mem_strdup(tmp.shr_access_rw);

        shr->shr_oemname = smb_kshare_oemname(shr->shr_name);
        shr->shr_flags = tmp.shr_flags | smb_kshare_is_admin(shr->shr_name);
        shr->shr_type = tmp.shr_type | smb_kshare_is_special(shr->shr_name);

        shr->shr_uid = tmp.shr_uid;
        shr->shr_gid = tmp.shr_gid;

        if ((shr->shr_flags & SMB_SHRF_AUTOHOME) == SMB_SHRF_AUTOHOME)
                shr->shr_autocnt = 1;

        return (shr);
}

#if 0
static void
smb_kshare_log(smb_kshare_t *shr)
{
        cmn_err(CE_NOTE, "Share info:");
        cmn_err(CE_NOTE, "\tname: %s", (shr->shr_name) ? shr->shr_name : "");
        cmn_err(CE_NOTE, "\tpath: %s", (shr->shr_path) ? shr->shr_path : "");
        cmn_err(CE_NOTE, "\tcmnt: (%s)",
            (shr->shr_cmnt) ? shr->shr_cmnt : "NULL");
        cmn_err(CE_NOTE, "\toemname: (%s)",
            (shr->shr_oemname) ? shr->shr_oemname : "NULL");
        cmn_err(CE_NOTE, "\tflags: %X", shr->shr_flags);
        cmn_err(CE_NOTE, "\ttype: %d", shr->shr_type);
}
#endif

/*
 * Compare function used by shares AVL
 */
static int
smb_kshare_cmp(const void *p1, const void *p2)
{
        smb_kshare_t *shr1 = (smb_kshare_t *)p1;
        smb_kshare_t *shr2 = (smb_kshare_t *)p2;
        int rc;

        ASSERT(shr1);
        ASSERT(shr1->shr_name);

        ASSERT(shr2);
        ASSERT(shr2->shr_name);

        rc = smb_strcasecmp(shr1->shr_name, shr2->shr_name, 0);

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

        if (rc > 0)
                return (1);

        return (0);
}

/*
 * This function is called by smb_avl routines whenever
 * there is a need to take a hold on a share structure
 * inside AVL
 */
static void
smb_kshare_hold(const void *p)
{
        smb_kshare_t *shr = (smb_kshare_t *)p;

        ASSERT(shr);
        ASSERT(shr->shr_magic == SMB_SHARE_MAGIC);

        mutex_enter(&shr->shr_mutex);
        shr->shr_refcnt++;
        mutex_exit(&shr->shr_mutex);
}

/*
 * This function must be called by smb_avl routines whenever
 * smb_kshare_hold is called and the hold needs to be released.
 */
static boolean_t
smb_kshare_rele(const void *p)
{
        smb_kshare_t *shr = (smb_kshare_t *)p;
        boolean_t destroy;

        ASSERT(shr);
        ASSERT(shr->shr_magic == SMB_SHARE_MAGIC);

        mutex_enter(&shr->shr_mutex);
        ASSERT(shr->shr_refcnt > 0);
        shr->shr_refcnt--;
        destroy = (shr->shr_refcnt == 0);
        mutex_exit(&shr->shr_mutex);

        return (destroy);
}

/*
 * Frees all the memory allocated for the given
 * share structure. It also removes the structure
 * from the share cache.
 */
static void
smb_kshare_destroy(void *p)
{
        smb_kshare_t *shr = (smb_kshare_t *)p;

        ASSERT(shr);
        ASSERT(shr->shr_magic == SMB_SHARE_MAGIC);

        smb_mem_free(shr->shr_name);
        smb_mem_free(shr->shr_path);
        smb_mem_free(shr->shr_cmnt);
        smb_mem_free(shr->shr_container);
        smb_mem_free(shr->shr_oemname);
        smb_mem_free(shr->shr_access_none);
        smb_mem_free(shr->shr_access_ro);
        smb_mem_free(shr->shr_access_rw);

        kmem_cache_free(smb_kshare_cache_share, shr);
}


/*
 * Generate an OEM name for the given share name.  If the name is
 * shorter than 13 bytes the oemname will be returned; otherwise NULL
 * is returned.
 */
static char *
smb_kshare_oemname(const char *shrname)
{
        smb_wchar_t *unibuf;
        char *oem_name;
        int length;

        length = strlen(shrname) + 1;

        oem_name = smb_mem_alloc(length);
        unibuf = smb_mem_alloc(length * sizeof (smb_wchar_t));

        (void) smb_mbstowcs(unibuf, shrname, length);

        if (ucstooem(oem_name, unibuf, length, OEM_CPG_850) == 0)
                (void) strcpy(oem_name, shrname);

        smb_mem_free(unibuf);

        if (strlen(oem_name) + 1 > SMB_SHARE_OEMNAME_MAX) {
                smb_mem_free(oem_name);
                return (NULL);
        }

        return (oem_name);
}

/*
 * Special share reserved for interprocess communication (IPC$) or
 * remote administration of the server (ADMIN$). Can also refer to
 * administrative shares such as C$, D$, E$, and so forth.
 */
static int
smb_kshare_is_special(const char *sharename)
{
        int len;

        if (sharename == NULL)
                return (0);

        if ((len = strlen(sharename)) == 0)
                return (0);

        if (sharename[len - 1] == '$')
                return (STYPE_SPECIAL);

        return (0);
}

/*
 * Check whether or not this is a default admin share: C$, D$ etc.
 */
static boolean_t
smb_kshare_is_admin(const char *sharename)
{
        if (sharename == NULL)
                return (B_FALSE);

        if (strlen(sharename) == 2 &&
            smb_isalpha(sharename[0]) && sharename[1] == '$') {
                return (B_TRUE);
        }

        return (B_FALSE);
}

/*
 * Decodes the given boolean share option.
 * If the option is present in the nvlist and it's value is true
 * returns the corresponding flag value, otherwise returns 0.
 */
static uint32_t
smb_kshare_decode_bool(nvlist_t *nvl, const char *propname, uint32_t flag)
{
        char *boolp;

        if (nvlist_lookup_string(nvl, propname, &boolp) == 0)
                if (strcasecmp(boolp, "true") == 0)
                        return (flag);

        return (0);
}

/*
 * Map a client-side caching (CSC) option to the appropriate share
 * flag.  Only one option is allowed; an error will be logged if
 * multiple options have been specified.  We don't need to do anything
 * about multiple values here because the SRVSVC will not recognize
 * a value containing multiple flags and will return the default value.
 *
 * If the option value is not recognized, it will be ignored: invalid
 * values will typically be caught and rejected by sharemgr.
 */
static void
smb_kshare_csc_flags(smb_kshare_t *shr, const char *value)
{
        int i;
        static struct {
                char *value;
                uint32_t flag;
        } cscopt[] = {
                { "disabled",   SMB_SHRF_CSC_DISABLED },
                { "manual",     SMB_SHRF_CSC_MANUAL },
                { "auto",       SMB_SHRF_CSC_AUTO },
                { "vdo",        SMB_SHRF_CSC_VDO }
        };

        if (value == NULL)
                return;

        for (i = 0; i < (sizeof (cscopt) / sizeof (cscopt[0])); ++i) {
                if (strcasecmp(value, cscopt[i].value) == 0) {
                        shr->shr_flags |= cscopt[i].flag;
                        break;
                }
        }

        switch (shr->shr_flags & SMB_SHRF_CSC_MASK) {
        case 0:
        case SMB_SHRF_CSC_DISABLED:
        case SMB_SHRF_CSC_MANUAL:
        case SMB_SHRF_CSC_AUTO:
        case SMB_SHRF_CSC_VDO:
                break;

        default:
                cmn_err(CE_NOTE, "csc option conflict: 0x%08x",
                    shr->shr_flags & SMB_SHRF_CSC_MASK);
                break;
        }
}

/*
 * This function processes the unexport event list and disconnects shares
 * asynchronously.  The function executes as a zone-specific thread.
 *
 * The server arg passed in is safe to use without a reference count, because
 * the server cannot be deleted until smb_thread_stop()/destroy() return,
 * which is also when the thread exits.
 */
/*ARGSUSED*/
static void
smb_kshare_unexport_thread(smb_thread_t *thread, void *arg)
{
        smb_server_t    *sv = arg;
        smb_unshare_t   *ux;

        while (smb_thread_continue(thread)) {
                while ((ux = list_head(&sv->sv_export.e_unexport_list.sl_list))
                    != NULL) {
                        smb_slist_remove(&sv->sv_export.e_unexport_list, ux);
                        (void) smb_server_unshare(ux->us_sharename);
                        kmem_cache_free(smb_kshare_cache_unexport, ux);
                }
        }
}

static boolean_t
smb_export_isready(smb_server_t *sv)
{
        boolean_t ready;

        mutex_enter(&sv->sv_export.e_mutex);
        ready = sv->sv_export.e_ready;
        mutex_exit(&sv->sv_export.e_mutex);

        return (ready);
}

#ifdef  _KERNEL
/*
 * Return 0 upon success. Otherwise > 0
 */
static int
smb_kshare_chk_dsrv_status(int opcode, smb_dr_ctx_t *dec_ctx)
{
        int status = smb_dr_get_int32(dec_ctx);
        int err;

        switch (status) {
        case SMB_SHARE_DSUCCESS:
                return (0);

        case SMB_SHARE_DERROR:
                err = smb_dr_get_uint32(dec_ctx);
                cmn_err(CE_WARN, "%d: Encountered door server error %d",
                    opcode, err);
                (void) smb_dr_decode_finish(dec_ctx);
                return (err);
        }

        ASSERT(0);
        return (EINVAL);
}
#endif  /* _KERNEL */