/*
 * 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.
 */

#include <sys/sunddi.h>
#include <sys/nbmlock.h>

#include <smbsrv/smb_kproto.h>
#include <smbsrv/smb_fsops.h>
#include <smbsrv/smbinfo.h>

static int smb_delete_check_path(smb_request_t *);
static int smb_delete_single_file(smb_request_t *, smb_error_t *);
static int smb_delete_multiple_files(smb_request_t *, smb_error_t *);
static int smb_delete_find_fname(smb_request_t *, smb_odir_t *, char *, int);
static int smb_delete_check_dosattr(smb_request_t *, smb_error_t *);
static int smb_delete_remove_file(smb_request_t *, smb_error_t *);

static void smb_delete_error(smb_error_t *, uint32_t, uint16_t, uint16_t);

/*
 * smb_com_delete
 *
 * The delete file message is sent to delete a data file. The appropriate
 * Tid and additional pathname are passed. Read only files may not be
 * deleted, the read-only attribute must be reset prior to file deletion.
 *
 * NT supports a hidden permission known as File Delete Child (FDC). If
 * the user has FullControl access to a directory, the user is permitted
 * to delete any object in the directory regardless of the permissions
 * on the object.
 *
 * Client Request                     Description
 * ================================== =================================
 * UCHAR WordCount;                   Count of parameter words = 1
 * USHORT SearchAttributes;
 * USHORT ByteCount;                  Count of data bytes; min = 2
 * UCHAR BufferFormat;                0x04
 * STRING FileName[];                 File name
 *
 * Multiple files may be deleted in response to a single request as
 * SMB_COM_DELETE supports wildcards
 *
 * SearchAttributes indicates the attributes that the target file(s) must
 * have. If the attribute is zero then only normal files are deleted. If
 * the system file or hidden attributes are specified then the delete is
 * inclusive -both the specified type(s) of files and normal files are
 * deleted. Attributes are described in the "Attribute Encoding" section
 * of this document.
 *
 * If bit0 of the Flags2 field of the SMB header is set, a pattern is
 * passed in, and the file has a long name, then the passed pattern  much
 * match the long file name for the delete to succeed. If bit0 is clear, a
 * pattern is passed in, and the file has a long name, then the passed
 * pattern must match the file's short name for the deletion to succeed.
 *
 * Server Response                    Description
 * ================================== =================================
 * UCHAR WordCount;                   Count of parameter words = 0
 * USHORT ByteCount;                  Count of data bytes = 0
 *
 * 4.2.10.1  Errors
 *
 * ERRDOS/ERRbadpath
 * ERRDOS/ERRbadfile
 * ERRDOS/ERRnoaccess
 * ERRDOS/ERRbadshare   # returned by NT for files that are already open
 * ERRHRD/ERRnowrite
 * ERRSRV/ERRaccess
 * ERRSRV/ERRinvdevice
 * ERRSRV/ERRinvid
 * ERRSRV/ERRbaduid
 */
smb_sdrc_t
smb_pre_delete(smb_request_t *sr)
{
        int rc;
        smb_fqi_t *fqi;

        fqi = &sr->arg.dirop.fqi;

        if ((rc = smbsr_decode_vwv(sr, "w", &fqi->fq_sattr)) == 0)
                rc = smbsr_decode_data(sr, "%S", sr, &fqi->fq_path.pn_path);

        DTRACE_SMB_START(op__Delete, smb_request_t *, sr); /* arg.dirop */

        return ((rc == 0) ? SDRC_SUCCESS : SDRC_ERROR);
}

void
smb_post_delete(smb_request_t *sr)
{
        DTRACE_SMB_DONE(op__Delete, smb_request_t *, sr);
}

/*
 * smb_com_delete
 *
 * 1. intialize, pre-process and validate pathname
 *
 * 2. process the path to get directory node & last_comp,
 *    store these in fqi
 *    - If smb_pathname_reduce cannot find the specified path,
 *      the error (ENOTDIR) is translated to NT_STATUS_OBJECT_PATH_NOT_FOUND
 *      if the target is a single file (no wildcards).  If there are
 *      wildcards in the last_comp, NT_STATUS_OBJECT_NAME_NOT_FOUND is
 *      used instead.
 *    - If the directory node is the mount point and the last component
 *      is ".." NT_STATUS_OBJECT_PATH_SYNTAX_BAD is returned.
 *
 * 3. check access permissions
 *
 * 4. invoke the appropriate deletion routine to find and remove
 *    the specified file(s).
 *    - if target is a single file (no wildcards) - smb_delete_single_file
 *    - if the target contains wildcards - smb_delete_multiple_files
 *
 * Returns: SDRC_SUCCESS or SDRC_ERROR
 */
smb_sdrc_t
smb_com_delete(smb_request_t *sr)
{
        int rc;
        smb_error_t err;
        uint32_t status;
        boolean_t wildcards = B_FALSE;
        smb_fqi_t *fqi;
        smb_pathname_t *pn;

        fqi = &sr->arg.dirop.fqi;
        pn = &fqi->fq_path;

        smb_pathname_init(sr, pn, pn->pn_path);
        if (!smb_pathname_validate(sr, pn))
                return (SDRC_ERROR);
        if (smb_delete_check_path(sr) != 0)
                return (SDRC_ERROR);

        wildcards = smb_contains_wildcards(pn->pn_fname);

        rc = smb_pathname_reduce(sr, sr->user_cr, fqi->fq_path.pn_path,
            sr->tid_tree->t_snode, sr->tid_tree->t_snode,
            &fqi->fq_dnode, fqi->fq_last_comp);
        if (rc == 0) {
                if (!smb_node_is_dir(fqi->fq_dnode)) {
                        smb_node_release(fqi->fq_dnode);
                        rc = ENOTDIR;
                }
        }
        if (rc != 0) {
                if (rc == ENOTDIR) {
                        if (wildcards)
                                status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
                        else
                                status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        smbsr_error(sr, status, ERRDOS, ERROR_FILE_NOT_FOUND);
                } else {
                        smbsr_errno(sr, rc);
                }

                return (SDRC_ERROR);
        }

        if ((fqi->fq_dnode == sr->tid_tree->t_snode) &&
            (strcmp(fqi->fq_last_comp, "..") == 0)) {
                smb_node_release(fqi->fq_dnode);
                smbsr_error(sr, NT_STATUS_OBJECT_PATH_SYNTAX_BAD,
                    ERRDOS, ERROR_BAD_PATHNAME);
                return (SDRC_ERROR);
        }

        rc = smb_fsop_access(sr, sr->user_cr, fqi->fq_dnode,
            FILE_LIST_DIRECTORY);
        if (rc != 0) {
                smb_node_release(fqi->fq_dnode);
                smbsr_error(sr, NT_STATUS_ACCESS_DENIED,
                    ERRDOS, ERROR_ACCESS_DENIED);
                return (SDRC_ERROR);
        }

        if (wildcards)
                rc = smb_delete_multiple_files(sr, &err);
        else
                rc = smb_delete_single_file(sr, &err);

        smb_node_release(fqi->fq_dnode);

        if (rc != 0)
                smbsr_set_error(sr, &err);
        else
                rc = smbsr_encode_empty_result(sr);

        return (rc == 0 ? SDRC_SUCCESS : SDRC_ERROR);
}

/*
 * smb_delete_single_file
 *
 * Find the specified file and, if its attributes match the search
 * criteria, delete it.
 *
 * Returns 0 - success (file deleted)
 *        -1 - error, err is populated with error details
 */
static int
smb_delete_single_file(smb_request_t *sr, smb_error_t *err)
{
        smb_fqi_t *fqi;
        smb_pathname_t *pn;

        fqi = &sr->arg.dirop.fqi;
        pn = &fqi->fq_path;

        /* pn already initialized and validated */
        if (!smb_validate_object_name(sr, pn)) {
                smb_delete_error(err, sr->smb_error.status,
                    ERRDOS, ERROR_INVALID_NAME);
                return (-1);
        }

        if (smb_fsop_lookup_name(sr, sr->user_cr, 0, sr->tid_tree->t_snode,
            fqi->fq_dnode, fqi->fq_last_comp, &fqi->fq_fnode) != 0) {
                smb_delete_error(err, NT_STATUS_OBJECT_NAME_NOT_FOUND,
                    ERRDOS, ERROR_FILE_NOT_FOUND);
                return (-1);
        }

        if (smb_delete_check_dosattr(sr, err) != 0) {
                smb_node_release(fqi->fq_fnode);
                return (-1);
        }

        if (smb_delete_remove_file(sr, err) != 0) {
                smb_node_release(fqi->fq_fnode);
                return (-1);
        }

        smb_node_release(fqi->fq_fnode);
        return (0);
}

/*
 * smb_delete_multiple_files
 *
 * For each matching file found by smb_delete_find_fname:
 * 1. lookup file
 * 2. check the file's attributes
 *    - The search ends with an error if a readonly file
 *      (NT_STATUS_CANNOT_DELETE) is matched.
 *    - The search ends (but not an error) if a directory is
 *      matched and the request's search did not include
 *      directories.
 *    - Otherwise, if smb_delete_check_dosattr fails the file
 *      is skipped and the search continues (at step 1)
 * 3. delete the file
 *
 * Returns 0 - success
 *        -1 - error, err is populated with error details
 */
static int
smb_delete_multiple_files(smb_request_t *sr, smb_error_t *err)
{
        char namebuf[MAXNAMELEN];
        smb_fqi_t *fqi;
        smb_odir_t *od;
        uint32_t status;
        int rc, deleted = 0;

        fqi = &sr->arg.dirop.fqi;

        /*
         * Specify all search attributes (SMB_SEARCH_ATTRIBUTES) so that
         * delete-specific checking can be done (smb_delete_check_dosattr).
         */
        status = smb_odir_openpath(sr, fqi->fq_path.pn_path,
            SMB_SEARCH_ATTRIBUTES, 0, &od);
        if (status != 0) {
                err->status = status;
                return (-1);
        }

        for (;;) {
                rc = smb_delete_find_fname(sr, od, namebuf, MAXNAMELEN);
                if (rc != 0)
                        break;

                rc = smb_fsop_lookup_name(sr, sr->user_cr, SMB_CASE_SENSITIVE,
                    sr->tid_tree->t_snode, fqi->fq_dnode,
                    namebuf, &fqi->fq_fnode);
                if (rc != 0)
                        break;

                if (smb_delete_check_dosattr(sr, err) != 0) {
                        smb_node_release(fqi->fq_fnode);
                        if (err->status == NT_STATUS_CANNOT_DELETE) {
                                smb_odir_close(od);
                                smb_odir_release(od);
                                return (-1);
                        }
                        if ((err->status == NT_STATUS_FILE_IS_A_DIRECTORY) &&
                            (SMB_SEARCH_DIRECTORY(fqi->fq_sattr) != 0))
                                break;
                        continue;
                }

                if (smb_delete_remove_file(sr, err) == 0) {
                        ++deleted;
                        smb_node_release(fqi->fq_fnode);
                        continue;
                }
                if (err->status == NT_STATUS_OBJECT_NAME_NOT_FOUND) {
                        smb_node_release(fqi->fq_fnode);
                        continue;
                }

                smb_odir_close(od);
                smb_odir_release(od);
                smb_node_release(fqi->fq_fnode);
                return (-1);
        }

        smb_odir_close(od);
        smb_odir_release(od);

        if ((rc != 0) && (rc != ENOENT)) {
                smbsr_map_errno(rc, err);
                return (-1);
        }

        if (deleted == 0) {
                smb_delete_error(err, NT_STATUS_NO_SUCH_FILE,
                    ERRDOS, ERROR_FILE_NOT_FOUND);
                return (-1);
        }

        return (0);
}

/*
 * smb_delete_find_fname
 *
 * Find next filename that matches search pattern and return it
 * in namebuf.
 *
 * Returns: 0 - success
 *          errno
 */
static int
smb_delete_find_fname(smb_request_t *sr, smb_odir_t *od, char *namebuf, int len)
{
        int             rc;
        smb_odirent_t   *odirent;
        boolean_t       eos;

        odirent = kmem_alloc(sizeof (smb_odirent_t), KM_SLEEP);

        rc = smb_odir_read(sr, od, odirent, &eos);
        if (rc == 0) {
                (void) strlcpy(namebuf, odirent->od_name, len);
        }
        kmem_free(odirent, sizeof (smb_odirent_t));
        return (rc);
}

/*
 * smb_delete_check_dosattr
 *
 * Check file's dos atributes to ensure that
 * 1. the file is not a directory - NT_STATUS_FILE_IS_A_DIRECTORY
 * 2. the file is not readonly - NT_STATUS_CANNOT_DELETE
 * 3. the file's dos attributes comply with the specified search attributes
 *     If the file is either hidden or system and those attributes
 *     are not specified in the search attributes - NT_STATUS_NO_SUCH_FILE
 *
 * Returns: 0 - file's attributes pass all checks
 *         -1 - err populated with error details
 */
static int
smb_delete_check_dosattr(smb_request_t *sr, smb_error_t *err)
{
        smb_fqi_t *fqi;
        smb_node_t *node;
        smb_attr_t attr;
        uint16_t sattr;

        fqi = &sr->arg.dirop.fqi;
        sattr = fqi->fq_sattr;
        node = fqi->fq_fnode;

        bzero(&attr, sizeof (attr));
        attr.sa_mask = SMB_AT_DOSATTR;
        if (smb_node_getattr(sr, node, zone_kcred(), NULL, &attr) != 0) {
                smb_delete_error(err, NT_STATUS_INTERNAL_ERROR,
                    ERRDOS, ERROR_INTERNAL_ERROR);
                return (-1);
        }

        if (attr.sa_dosattr & FILE_ATTRIBUTE_DIRECTORY) {
                smb_delete_error(err, NT_STATUS_FILE_IS_A_DIRECTORY,
                    ERRDOS, ERROR_ACCESS_DENIED);
                return (-1);
        }

        if (SMB_PATHFILE_IS_READONLY(sr, node)) {
                smb_delete_error(err, NT_STATUS_CANNOT_DELETE,
                    ERRDOS, ERROR_ACCESS_DENIED);
                return (-1);
        }

        if ((attr.sa_dosattr & FILE_ATTRIBUTE_HIDDEN) &&
            !(SMB_SEARCH_HIDDEN(sattr))) {
                smb_delete_error(err, NT_STATUS_NO_SUCH_FILE,
                    ERRDOS, ERROR_FILE_NOT_FOUND);
                return (-1);
        }

        if ((attr.sa_dosattr & FILE_ATTRIBUTE_SYSTEM) &&
            !(SMB_SEARCH_SYSTEM(sattr))) {
                smb_delete_error(err, NT_STATUS_NO_SUCH_FILE,
                    ERRDOS, ERROR_FILE_NOT_FOUND);
                return (-1);
        }

        return (0);
}

/*
 * smb_delete_remove_file
 *
 * For consistency with Windows 2000, the range check should be done
 * after checking for sharing violations.  Attempting to delete a
 * locked file will result in sharing violation, which is the same
 * thing that will happen if you try to delete a non-locked open file.
 *
 * Note that windows 2000 rejects lock requests on open files that
 * have been opened with metadata open modes.  The error is
 * STATUS_ACCESS_DENIED.
 *
 * NT does not always close a file immediately, which can cause the
 * share and access checking to fail (the node refcnt is greater
 * than one), and the file doesn't get deleted. Breaking the oplock
 * before share and lock checking gives the client a chance to
 * close the file.
 *
 * Returns: 0 - success
 *         -1 - error, err populated with error details
 */
static int
smb_delete_remove_file(smb_request_t *sr, smb_error_t *err)
{
        int rc;
        uint32_t status;
        smb_fqi_t *fqi;
        smb_node_t *node;
        uint32_t flags = 0;

        fqi = &sr->arg.dirop.fqi;
        node = fqi->fq_fnode;

        /*
         * Break BATCH oplock before ofile checks. If a client
         * has a file open, this will force a flush or close,
         * which may affect the outcome of any share checking.
         */
        status = smb_oplock_break_DELETE(node, NULL);
        if (status == NT_STATUS_OPLOCK_BREAK_IN_PROGRESS) {
                (void) smb_oplock_wait_break(sr, node, 0);
                status = 0;
        }
        if (status != 0) {
                err->status = status;
                return (-1);
        }

        smb_node_rdlock(node);
        status = smb_node_delete_check(node);
        if (status != NT_STATUS_SUCCESS) {
                smb_node_unlock(node);
                smb_delete_error(err, NT_STATUS_SHARING_VIOLATION,
                    ERRDOS, ERROR_SHARING_VIOLATION);
                return (-1);
        }

        /*
         * Note, the combination of these two:
         *      smb_node_rdlock(node);
         *      nbl_start_crit(node->vp, RW_READER);
         * is equivalent to this call:
         *      smb_node_start_crit(node, RW_READER)
         *
         * Cleanup after this point should use:
         *      smb_node_end_crit(node)
         */
        nbl_start_crit(node->vp, RW_READER);

        /*
         * This checks nbl_share_conflict, nbl_lock_conflict
         */
        status = smb_nbl_conflict(node, 0, UINT64_MAX, NBL_REMOVE);
        if (status == NT_STATUS_SHARING_VIOLATION) {
                smb_node_end_crit(node);
                smb_delete_error(err, NT_STATUS_SHARING_VIOLATION,
                    ERRDOS, ERROR_SHARING_VIOLATION);
                return (-1);
        }
        if (status != NT_STATUS_SUCCESS) {
                smb_node_end_crit(node);
                smb_delete_error(err, NT_STATUS_ACCESS_DENIED,
                    ERRDOS, ERROR_ACCESS_DENIED);
                return (-1);
        }

        if (SMB_TREE_SUPPORTS_CATIA(sr))
                flags |= SMB_CATIA;

        rc = smb_fsop_remove(sr, sr->user_cr, node->n_dnode,
            node->od_name, flags);
        if (rc != 0) {
                smbsr_map_errno(rc, err);
                rc = -1;
        }

        smb_node_end_crit(node);
        return (rc);
}


/*
 * smb_delete_check_path
 *
 * smb_pathname_validate() should already have been used to
 * perform initial validation on the pathname. Additional
 * request specific validation of the filename is performed
 * here.
 *
 * - pn->pn_fname is NULL should result in NT_STATUS_FILE_IS_A_DIRECTORY
 *
 * - Any wildcard filename that resolves to '.' should result in
 *   NT_STATUS_OBJECT_NAME_INVALID if the search attributes include
 *   FILE_ATTRIBUTE_DIRECTORY
 *
 * Returns:
 *   0: path is valid.
 *  -1: path is invalid. Sets error information in sr.
 */
static int
smb_delete_check_path(smb_request_t *sr)
{
        smb_fqi_t *fqi = &sr->arg.dirop.fqi;
        smb_pathname_t *pn = &fqi->fq_path;

        if (pn->pn_fname == NULL) {
                smbsr_error(sr, NT_STATUS_FILE_IS_A_DIRECTORY,
                    ERRDOS, ERROR_ACCESS_DENIED);
                return (-1);
        }

        /* fname component is, or resolves to, '.' (dot) */
        if ((strcmp(pn->pn_fname, ".") == 0) ||
            (SMB_SEARCH_DIRECTORY(fqi->fq_sattr) &&
            (smb_match(pn->pn_fname, ".", B_FALSE)))) {
                smbsr_error(sr, NT_STATUS_OBJECT_NAME_INVALID,
                    ERRDOS, ERROR_INVALID_NAME);
                return (-1);
        }

        return (0);
}

/*
 * smb_delete_error
 */
static void
smb_delete_error(smb_error_t *err,
    uint32_t status, uint16_t errcls, uint16_t errcode)
{
        err->status = status;
        err->errcls = errcls;
        err->errcode = errcode;
}