/*      $NetBSD: msdosfs_conv.c,v 1.25 1997/11/17 15:36:40 ws Exp $     */

/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (C) 1995, 1997 Wolfgang Solfrank.
 * Copyright (C) 1995, 1997 TooLs GmbH.
 * All rights reserved.
 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*-
 * Written by Paul Popelka (paulp@uts.amdahl.com)
 *
 * You can do anything you want with this software, just don't say you wrote
 * it, and don't remove this notice.
 *
 * This software is provided "as is".
 *
 * The author supplies this software to be publicly redistributed on the
 * understanding that the author is not responsible for the correct
 * functioning of this software in any circumstances and is not liable for
 * any damages caused by this software.
 *
 * October 1992
 */


// Modified to support the Haiku FAT driver.

#include <sys/param.h>
#include <sys/systm.h>
#ifndef FS_SHELL
#include <dirent.h>
#endif // !FS_SHELL
#include <sys/iconv.h>
#include <sys/malloc.h>
#include <sys/mount.h>

#include <fs/msdosfs/bpb.h>
#include <fs/msdosfs/direntry.h>
#include <fs/msdosfs/msdosfsmount.h>

// Haiku port
#include "encodings.h"

extern struct iconv_functions *msdosfs_iconv;

static int mbsadjpos(const char **, size_t, size_t, int, int, void *handle);
static u_char * dos2unixchr(u_char *, const u_char **, size_t *, int, struct msdosfsmount *);
static uint16_t unix2doschr(const u_char **, size_t *, struct msdosfsmount *);
static u_char * win2unixchr(u_char *, uint16_t, struct msdosfsmount *);
static uint16_t unix2winchr(const u_char **, size_t *, int, struct msdosfsmount *);

/*
 * 0 - character disallowed in long file name.
 * 1 - character should be replaced by '_' in DOS file name,
 *     and generation number inserted.
 * 2 - character ('.' and ' ') should be skipped in DOS file name,
 *     and generation number inserted.
 */
static const u_char
unix2dos[256] = {
/* iso8859-1 -> cp850 */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 00-07 */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 08-0f */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 10-17 */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 18-1f */
        2,    0x21, 0,    0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
        0x28, 0x29, 0,    1,    1,    0x2d, 2,    0,    /* 28-2f */
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
        0x38, 0x39, 0,    1,    0,    1,    0,    0,    /* 38-3f */
        0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 40-47 */
        0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 48-4f */
        0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 50-57 */
        0x58, 0x59, 0x5a, 1,    0,    1,    0x5e, 0x5f, /* 58-5f */
        0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 60-67 */
        0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 68-6f */
        0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 70-77 */
        0x58, 0x59, 0x5a, 0x7b, 0,    0x7d, 0x7e, 0,    /* 78-7f */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 80-87 */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 88-8f */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 90-97 */
        0,    0,    0,    0,    0,    0,    0,    0,    /* 98-9f */
        0,    0xad, 0xbd, 0x9c, 0xcf, 0xbe, 0xdd, 0xf5, /* a0-a7 */
        0xf9, 0xb8, 0xa6, 0xae, 0xaa, 0xf0, 0xa9, 0xee, /* a8-af */
        0xf8, 0xf1, 0xfd, 0xfc, 0xef, 0xe6, 0xf4, 0xfa, /* b0-b7 */
        0xf7, 0xfb, 0xa7, 0xaf, 0xac, 0xab, 0xf3, 0xa8, /* b8-bf */
        0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* c0-c7 */
        0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* c8-cf */
        0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0x9e, /* d0-d7 */
        0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0xe1, /* d8-df */
        0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* e0-e7 */
        0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* e8-ef */
        0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0xf6, /* f0-f7 */
        0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0x98, /* f8-ff */
};

static const u_char
dos2unix[256] = {
/* cp850 -> iso8859-1 */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 00-07 */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 08-0f */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 10-17 */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 18-1f */
        0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
        0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 28-2f */
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
        0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 38-3f */
        0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 40-47 */
        0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 48-4f */
        0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 50-57 */
        0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 58-5f */
        0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 60-67 */
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 68-6f */
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 70-77 */
        0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 78-7f */
        0xc7, 0xfc, 0xe9, 0xe2, 0xe4, 0xe0, 0xe5, 0xe7, /* 80-87 */
        0xea, 0xeb, 0xe8, 0xef, 0xee, 0xec, 0xc4, 0xc5, /* 88-8f */
        0xc9, 0xe6, 0xc6, 0xf4, 0xf6, 0xf2, 0xfb, 0xf9, /* 90-97 */
        0xff, 0xd6, 0xdc, 0xf8, 0xa3, 0xd8, 0xd7, 0x3f, /* 98-9f */
        0xe1, 0xed, 0xf3, 0xfa, 0xf1, 0xd1, 0xaa, 0xba, /* a0-a7 */
        0xbf, 0xae, 0xac, 0xbd, 0xbc, 0xa1, 0xab, 0xbb, /* a8-af */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0xc1, 0xc2, 0xc0, /* b0-b7 */
        0xa9, 0x3f, 0x3f, 0x3f, 0x3f, 0xa2, 0xa5, 0x3f, /* b8-bf */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0xe3, 0xc3, /* c0-c7 */
        0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0xa4, /* c8-cf */
        0xf0, 0xd0, 0xca, 0xcb, 0xc8, 0x3f, 0xcd, 0xce, /* d0-d7 */
        0xcf, 0x3f, 0x3f, 0x3f, 0x3f, 0xa6, 0xcc, 0x3f, /* d8-df */
        0xd3, 0xdf, 0xd4, 0xd2, 0xf5, 0xd5, 0xb5, 0xfe, /* e0-e7 */
        0xde, 0xda, 0xdb, 0xd9, 0xfd, 0xdd, 0xaf, 0x3f, /* e8-ef */
        0xad, 0xb1, 0x3f, 0xbe, 0xb6, 0xa7, 0xf7, 0xb8, /* f0-f7 */
        0xb0, 0xa8, 0xb7, 0xb9, 0xb3, 0xb2, 0x3f, 0x3f, /* f8-ff */
};

static const u_char
u2l[256] = {
/* tolower */
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 00-07 */
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 08-0f */
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 10-17 */
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 18-1f */
        0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
        0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 28-2f */
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
        0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 38-3f */
        0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 40-47 */
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 48-4f */
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 50-57 */
        0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 58-5f */
        0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 60-67 */
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 68-6f */
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 70-77 */
        0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 78-7f */
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 80-87 */
        0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 88-8f */
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 90-97 */
        0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 98-9f */
        0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* a0-a7 */
        0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* a8-af */
        0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* b0-b7 */
        0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* b8-bf */
        0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* c0-c7 */
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* c8-cf */
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xd7, /* d0-d7 */
        0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xdf, /* d8-df */
        0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* e0-e7 */
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* e8-ef */
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* f0-f7 */
        0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* f8-ff */
};

static const u_char
l2u[256] = {
/* toupper */
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 00-07 */
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 08-0f */
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 10-17 */
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 18-1f */
        0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
        0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 28-2f */
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
        0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 38-3f */
        0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 40-47 */
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 48-4f */
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 50-57 */
        0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 58-5f */
        0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 60-67 */
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 68-6f */
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 70-77 */
        0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 78-7f */
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 80-87 */
        0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 88-8f */
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 90-97 */
        0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 98-9f */
        0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* a0-a7 */
        0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* a8-af */
        0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* b0-b7 */
        0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* b8-bf */
        0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* c0-c7 */
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* c8-cf */
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xd7, /* d0-d7 */
        0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xdf, /* d8-df */
        0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* e0-e7 */
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* e8-ef */
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* f0-f7 */
        0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* f8-ff */
};

/*
 * DOS filenames are made of 2 parts, the name part and the extension part.
 * The name part is 8 characters long and the extension part is 3
 * characters long.  They may contain trailing blanks if the name or
 * extension are not long enough to fill their respective fields.
 */

/*
 * Convert a DOS filename to a unix filename. And, return the number of
 * characters in the resulting unix filename excluding the terminating
 * null.
 */
int
dos2unixfn(u_char dn[11], u_char *un, int lower, struct msdosfsmount *pmp)
{
        size_t i;
        int thislong = 0;
        u_char *c, tmpbuf[5];

        /*
         * If first char of the filename is SLOT_E5 (0x05), then the real
         * first char of the filename should be 0xe5. But, they couldn't
         * just have a 0xe5 mean 0xe5 because that is used to mean a freed
         * directory slot. Another dos quirk.
         */
        if (*dn == SLOT_E5)
                *dn = 0xe5;

        /*
         * Copy the name portion into the unix filename string.
         */
        for (i = 8; i > 0 && *dn != ' ';) {
                c = dos2unixchr(tmpbuf, __DECONST(const u_char **, &dn), &i,
                    lower & LCASE_BASE, pmp);
                while (*c != '\0') {
                        *un++ = *c++;
                        thislong++;
                }
        }
        dn += i;

        /*
         * Now, if there is an extension then put in a period and copy in
         * the extension.
         */
        if (*dn != ' ') {
                *un++ = '.';
                thislong++;
                for (i = 3; i > 0 && *dn != ' ';) {
                        c = dos2unixchr(tmpbuf, __DECONST(const u_char **, &dn),
                            &i, lower & LCASE_EXT, pmp);
                        while (*c != '\0') {
                                *un++ = *c++;
                                thislong++;
                        }
                }
        }
        *un++ = 0;

        return (thislong);
}

/*
 * Convert a unix filename to a DOS filename according to Win95 rules.
 * If applicable and gen is not 0, it is inserted into the converted
 * filename as a generation number.
 * Returns
 *      0 if name couldn't be converted
 *      1 if the converted name is the same as the original
 *        (no long filename entry necessary for Win95)
 *      2 if conversion was successful
 *      3 if conversion was successful and generation number was inserted
 */
int
unix2dosfn(const u_char *un, u_char dn[12], size_t unlen, u_int gen,
    struct msdosfsmount *pmp)
{
        ssize_t i, j;
        int l;
        int conv = 1;
        const u_char *cp, *dp, *dp1;
        u_char gentext[6], *wcp;
        uint16_t c;

        // Haiku port: enable SJIS encoding if appropriate
        int sjis = 0;
        int status = 0;
        int unicodeSize = MAXNAMLEN * 2 + 1;
        uchar unicodeString[unicodeSize];
        int resultLength = 0;
#ifndef USER
        // We don't have access to libiconv, so the driver will default to code page 850.
        // Check for Japanese characters in un and use SJIS encoding instead if found.
        status = B_TO_POSIX_ERROR(utf8_to_unicode((const char*) un, unicodeString, unicodeSize));
        if (status < 0)
                return 0;
        else
                resultLength = status;
        for (i = 0; i < resultLength; i += 2) {
                uint16 unicodeChar;
                memcpy(&unicodeChar, unicodeString + i, 2);
                if (is_unicode_japanese(B_LENDIAN_TO_HOST_INT16(unicodeChar))) {
                        sjis = 1;
                        break;
                }
        }
#endif // !USER

        /*
         * Fill the dos filename string with blanks. These are DOS's pad
         * characters.
         */
        for (i = 0; i < 11; i++)
                dn[i] = ' ';
        dn[11] = 0;

        if (sjis == 1) {
                status = B_TO_POSIX_ERROR(
                        generate_short_name_sjis(un, (const uint16*) unicodeString, resultLength, dn));
                if (status != 0)
                        return 0;
                conv = 3;
        } else {
                /*
                 * The filenames "." and ".." are handled specially, since they
                 * don't follow dos filename rules.
                 */
                if (un[0] == '.' && unlen == 1) {
                        dn[0] = '.';
                        return gen <= 1;
                }
                if (un[0] == '.' && un[1] == '.' && unlen == 2) {
                        dn[0] = '.';
                        dn[1] = '.';
                        return gen <= 1;
                }

                /*
                 * Filenames with only blanks and dots are not allowed!
                 */
                for (cp = un, i = unlen; --i >= 0; cp++)
                        if (*cp != ' ' && *cp != '.')
                                break;
                if (i < 0)
                        return 0;

                /*
                 * Filenames with some characters are not allowed!
                 */
                for (cp = un, i = unlen; i > 0;)
                        if (unix2doschr(&cp, (size_t *)&i, pmp) == 0)
                                return 0;

                /*
                 * Now find the extension
                 * Note: dot as first char doesn't start extension
                 *       and trailing dots and blanks are ignored
                 * Note(2003/7): It seems recent Windows has
                 *       defferent rule than this code, that Windows
                 *       ignores all dots before extension, and use all
                 *       chars as filename except for dots.
                 */
                dp = dp1 = NULL;
                for (cp = un + 1, i = unlen - 1; --i >= 0;) {
                        switch (*cp++) {
                        case '.':
                                if (!dp1)
                                        dp1 = cp;
                                break;
                        case ' ':
                                break;
                        default:
                                if (dp1)
                                        dp = dp1;
                                dp1 = NULL;
                                break;
                        }
                }

                /*
                 * Now convert it (this part is for extension).
                 * As Windows XP do, if it's not ascii char,
                 * this function should return 2 or 3, so that checkng out Unicode name.
                 */
                if (dp) {
                        if (dp1)
                                l = dp1 - dp;
                        else
                                l = unlen - (dp - un);
                        for (cp = dp, i = l, j = 8; i > 0 && j < 11; j++) {
                                c = unix2doschr(&cp, (size_t *)&i, pmp);
                                if (c & 0xff00) {
                                        dn[j] = c >> 8;
                                        if (++j < 11) {
                                                dn[j] = c;
                                                if (conv != 3)
                                                        conv = 2;
                                                continue;
                                        } else {
                                                conv = 3;
                                                dn[j-1] = ' ';
                                                break;
                                        }
                                } else {
                                        dn[j] = c;
                                }
                                if (((dn[j] & 0x80) || *(cp - 1) != dn[j]) && conv != 3)
                                        conv = 2;
                                if (dn[j] == 1) {
                                        conv = 3;
                                        dn[j] = '_';
                                }
                                if (dn[j] == 2) {
                                        conv = 3;
                                        dn[j--] = ' ';
                                }
                        }
                        if (i > 0)
                                conv = 3;
                        dp--;
                } else {
                        for (dp = cp; *--dp == ' ' || *dp == '.';);
                        dp++;
                }

                /*
                 * Now convert the rest of the name
                 */
                for (i = dp - un, j = 0; un < dp && j < 8; j++) {
                        c = unix2doschr(&un, (size_t *)&i, pmp);
                                // Haiku port:  cast added to avoid compiler warning
                        if (c & 0xff00) {
                                dn[j] = c >> 8;
                                if (++j < 8) {
                                        dn[j] = c;
                                        if (conv != 3)
                                                conv = 2;
                                        continue;
                                } else {
                                        conv = 3;
                                        dn[j-1] = ' ';
                                        break;
                                }
                        } else {
                                dn[j] = c;
                        }
                        if (((dn[j] & 0x80) || *(un - 1) != dn[j]) && conv != 3)
                                conv = 2;
                        if (dn[j] == 1) {
                                conv = 3;
                                dn[j] = '_';
                        }
                        if (dn[j] == 2) {
                                conv = 3;
                                dn[j--] = ' ';
                        }
                }
                if (un < dp)
                        conv = 3;
                /*
                 * If we didn't have any chars in filename,
                 * generate a default
                 */
                if (!j)
                        dn[0] = '_';

        }

        /*
         * If there wasn't any char dropped,
         * there is no place for generation numbers
         */
        if (conv != 3) {
                if (gen > 1)
                        conv = 0;
                goto done;
        }

        /*
         * Now insert the generation number into the filename part
         */
        if (gen == 0)
                goto done;
        for (wcp = gentext + sizeof(gentext); wcp > gentext && gen; gen /= 10)
                *--wcp = gen % 10 + '0';
        if (gen) {
                conv = 0;
                goto done;
        }
        for (i = 8; dn[--i] == ' ';);
        i++;
        if (gentext + sizeof(gentext) - wcp + 1 > 8 - i)
                i = 8 - (gentext + sizeof(gentext) - wcp + 1);
        /*
         * Correct posision to where insert the generation number
         */
        cp = dn;
        i -= mbsadjpos((const char**)&cp, i, unlen, 1, pmp->pm_flags, pmp->pm_d2u);

        dn[i++] = '~';
        while (wcp < gentext + sizeof(gentext))
                dn[i++] = *wcp++;

        /*
         * Tail of the filename should be space
         */
        while (i < 8)
                dn[i++] = ' ';
        conv = 3;

done:
        /*
         * The first character cannot be E5,
         * because that means a deleted entry
         */
        if (dn[0] == 0xe5)
                dn[0] = SLOT_E5;

        return conv;
}

/*
 * Create a Win95 long name directory entry
 * Note: assumes that the filename is valid,
 *       i.e. doesn't consist solely of blanks and dots
 */
int
unix2winfn(const u_char *un, size_t unlen, struct winentry *wep, int cnt,
    int chksum, struct msdosfsmount *pmp)
{
        uint8_t *wcp;
        int i, end;
        uint16_t code;

        /*
         * Drop trailing blanks and dots
         */
        unlen = winLenFixup(un, unlen);

        /*
         * Cut *un for this slot
         */
        unlen = mbsadjpos((const char **)&un, unlen, (cnt - 1) * WIN_CHARS, 2,
                          pmp->pm_flags, pmp->pm_u2w);

        /*
         * Initialize winentry to some useful default
         */
        memset(wep, 0xff, sizeof(*wep));
        wep->weCnt = cnt;
        wep->weAttributes = ATTR_WIN95;
        wep->weReserved1 = 0;
        wep->weChksum = chksum;
        wep->weReserved2 = 0;

        /*
         * Now convert the filename parts
         */
        end = 0;
        for (wcp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0 && !end;) {
                code = unix2winchr(&un, &unlen, 0, pmp);
                *wcp++ = code;
                *wcp++ = code >> 8;
                if (!code)
                        end = WIN_LAST;
        }
        for (wcp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0 && !end;) {
                code = unix2winchr(&un, &unlen, 0, pmp);
                *wcp++ = code;
                *wcp++ = code >> 8;
                if (!code)
                        end = WIN_LAST;
        }
        for (wcp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0 && !end;) {
                code = unix2winchr(&un, &unlen, 0, pmp);
                *wcp++ = code;
                *wcp++ = code >> 8;
                if (!code)
                        end = WIN_LAST;
        }
        if (!unlen)
                end = WIN_LAST;
        wep->weCnt |= end;
        return !end;
}

/*
 * Compare our filename to the one in the Win95 entry
 * Returns the checksum or -1 if no match
 */
int
winChkName(struct mbnambuf *nbp, const u_char *un, size_t unlen, int chksum,
    struct msdosfsmount *pmp)
{
        // Haiku port: uses Haiku's struct dirent, which is a flexible struct and has no d_namlen.
        size_t len;
        uint16_t c1, c2;
        char *np;
                // Haiku port: type changed to avoid compiler warning
        struct dirent* dirbuf = (struct dirent*)alloca(sizeof(struct dirent) + MAXNAMLEN + 1);

        /*
         * We already have winentry in *nbp.
         */
        if (!mbnambuf_flush(nbp, dirbuf) || (len = strlen(dirbuf->d_name)) == 0)
                return -1;

#ifdef MSDOSFS_DEBUG
        printf("winChkName(): un=%s:%zu,d_name=%s:%d\n", un, unlen,
                                                        dirbuf->d_name,
                                                        len);
#endif

        /*
         * Compare the name parts
         */
        if (unlen != len)
                return -2;

        for (np = dirbuf->d_name; unlen > 0 && len > 0;) {
                /*
                 * Comparison must be case insensitive, because FAT disallows
                 * to look up or create files in case sensitive even when
                 * it's a long file name.
                 */
                c1 = unix2winchr(__DECONST(const u_char **, &np), &len,
                    LCASE_BASE, pmp);
                c2 = unix2winchr(&un, &unlen, LCASE_BASE, pmp);
                if (c1 != c2)
                        return -2;
        }
        return chksum;
}

/*
 * Convert Win95 filename to dirbuf.
 * Returns the checksum or -1 if impossible
 */
int
win2unixfn(struct mbnambuf *nbp, struct winentry *wep, int chksum,
    struct msdosfsmount *pmp)
{
        u_char *c, tmpbuf[5];
        uint8_t *cp;
        char *np, name[WIN_CHARS * 3 + 1];
                // Haiku port:  type changed to avoid compiler warning
        uint16_t code;
        int i;

        if ((wep->weCnt&WIN_CNT) > howmany(WIN_MAXLEN, WIN_CHARS)
            || !(wep->weCnt&WIN_CNT))
                return -1;

        /*
         * First compare checksums
         */
        if (wep->weCnt&WIN_LAST) {
                chksum = wep->weChksum;
        } else if (chksum != wep->weChksum)
                chksum = -1;
        if (chksum == -1)
                return -1;

        /*
         * Convert the name parts
         */
        np = name;
        for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
                code = (cp[1] << 8) | cp[0];
                switch (code) {
                case 0:
                        *np = '\0';
                        if (mbnambuf_write(nbp, name,
                            (wep->weCnt & WIN_CNT) - 1) != 0)
                                return -1;
                        return chksum;
                case '/':
                        *np = '\0';
                        return -1;
                default:
                        c = win2unixchr(tmpbuf, code, pmp);
                        while (*c != '\0')
                                *np++ = *c++;
                        break;
                }
                cp += 2;
        }
        for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
                code = (cp[1] << 8) | cp[0];
                switch (code) {
                case 0:
                        *np = '\0';
                        if (mbnambuf_write(nbp, name,
                            (wep->weCnt & WIN_CNT) - 1) != 0)
                                return -1;
                        return chksum;
                case '/':
                        *np = '\0';
                        return -1;
                default:
                        c = win2unixchr(tmpbuf, code, pmp);
                        while (*c != '\0')
                                *np++ = *c++;
                        break;
                }
                cp += 2;
        }
        for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
                code = (cp[1] << 8) | cp[0];
                switch (code) {
                case 0:
                        *np = '\0';
                        if (mbnambuf_write(nbp, name,
                            (wep->weCnt & WIN_CNT) - 1) != 0)
                                return -1;
                        return chksum;
                case '/':
                        *np = '\0';
                        return -1;
                default:
                        c = win2unixchr(tmpbuf, code, pmp);
                        while (*c != '\0')
                                *np++ = *c++;
                        break;
                }
                cp += 2;
        }
        *np = '\0';
        if (mbnambuf_write(nbp, name, (wep->weCnt & WIN_CNT) - 1) != 0)
                return -1;
        return chksum;
}

/*
 * Compute the unrolled checksum of a DOS filename for Win95 LFN use.
 */
uint8_t
winChksum(uint8_t *name)
{
        int i;
        uint8_t s;

        for (s = 0, i = 11; --i >= 0; s += *name++)
                s = (s << 7)|(s >> 1);
        return (s);
}

/*
 * Determine the number of slots necessary for Win95 names
 */
int
winSlotCnt(const u_char *un, size_t unlen, struct msdosfsmount *pmp)
{
        size_t wlen;
        char wn[WIN_MAXLEN * 2 + 1], *wnp;

        unlen = winLenFixup(un, unlen);

        if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
                wlen = WIN_MAXLEN * 2;
                wnp = wn;
                msdosfs_iconv->conv(pmp->pm_u2w, (const char **)&un, &unlen, &wnp, &wlen);
                if (unlen > 0)
                        return 0;
                return howmany(WIN_MAXLEN - wlen/2, WIN_CHARS);
        }

        if (unlen > WIN_MAXLEN)
                return 0;
        return howmany(unlen, WIN_CHARS);
}

/*
 * Determine the number of bytes necessary for Win95 names
 */
size_t
winLenFixup(const u_char *un, size_t unlen)
{
        for (un += unlen; unlen > 0; unlen--)
                if (*--un != ' ' && *un != '.')
                        break;
        return unlen;
}

/*
 * Store an area with multi byte string instr, and returns left
 * byte of instr and moves pointer forward. The area's size is
 * inlen or outlen.
 */
static int
mbsadjpos(const char **instr, size_t inlen, size_t outlen, int weight, int flag, void *handle)
{
        char *outp, outstr[outlen * weight + 1];

        if (flag & MSDOSFSMNT_KICONV && msdosfs_iconv) {
                outp = outstr;
                outlen *= weight;
                msdosfs_iconv->conv(handle, instr, &inlen, &outp, &outlen);
                return (inlen);
        }

        (*instr) += min(inlen, outlen);
        return (inlen - min(inlen, outlen));
}

/*
 * Convert DOS char to Local char
 */
static u_char *
dos2unixchr(u_char *outbuf, const u_char **instr, size_t *ilen, int lower, struct msdosfsmount *pmp)
{
        u_char c, *outp;
        size_t len, olen;

        outp = outbuf;
        if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
                olen = len = 4;

                if (lower & (LCASE_BASE | LCASE_EXT))
                        msdosfs_iconv->convchr_case(pmp->pm_d2u, (const char **)instr,
                                                  ilen, (char **)&outp, &olen, KICONV_LOWER);
                else
                        msdosfs_iconv->convchr(pmp->pm_d2u, (const char **)instr,
                                             ilen, (char **)&outp, &olen);
                len -= olen;

                /*
                 * return '?' if failed to convert
                 */
                if (len == 0) {
                        (*ilen)--;
                        (*instr)++;
                        *outp++ = '?';
                }
        } else {
                (*ilen)--;
                c = *(*instr)++;
                c = dos2unix[c];
                if (lower & (LCASE_BASE | LCASE_EXT))
                        c = u2l[c];
                *outp++ = c;
                outbuf[1] = '\0';
        }

        *outp = '\0';
        outp = outbuf;
        return (outp);
}

/*
 * Convert Local char to DOS char
 */
static uint16_t
unix2doschr(const u_char **instr, size_t *ilen, struct msdosfsmount *pmp)
{
        u_char c;
        char *up, *outp, unicode[3], outbuf[3];
        uint16_t wc;
        size_t len, ucslen, unixlen, olen;

        if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
                /*
                 * to hide an invisible character, using a unicode filter
                 */
                ucslen = 2;
                len = *ilen;
                up = unicode;
                msdosfs_iconv->convchr(pmp->pm_u2w, (const char **)instr,
                                     ilen, &up, &ucslen);
                unixlen = len - *ilen;

                /*
                 * cannot be converted
                 */
                if (unixlen == 0) {
                        (*ilen)--;
                        (*instr)++;
                        return (0);
                }

                /*
                 * return magic number for ascii char
                 */
                if (unixlen == 1) {
                        c = *(*instr -1);
                        if (! (c & 0x80)) {
                                c = unix2dos[c];
                                if (c <= 2)
                                        return (c);
                        }
                }

                /*
                 * now convert using libiconv
                 */
                *instr -= unixlen;
                *ilen = len;

                olen = len = 2;
                outp = outbuf;
                msdosfs_iconv->convchr_case(pmp->pm_u2d, (const char **)instr,
                                          ilen, &outp, &olen, KICONV_FROM_UPPER);
                len -= olen;

                /*
                 * cannot be converted, but has unicode char, should return magic number
                 */
                if (len == 0) {
                        (*ilen) -= unixlen;
                        (*instr) += unixlen;
                        return (1);
                }

                wc = 0;
                while(len--)
                        wc |= (*(outp - len - 1) & 0xff) << (len << 3);
                return (wc);
        }

        (*ilen)--;
        c = *(*instr)++;
        c = l2u[c];
        c = unix2dos[c];
        return ((uint16_t)c);
}

/*
 * Convert Windows char to Local char
 */
static u_char *
win2unixchr(u_char *outbuf, uint16_t wc, struct msdosfsmount *pmp)
{
        u_char *inp, *outp, inbuf[3];
        size_t ilen, olen, len;

        outp = outbuf;
        if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
                inbuf[0] = (u_char)(wc>>8);
                inbuf[1] = (u_char)wc;
                inbuf[2] = '\0';

                ilen = 2;
                olen = len = 4;
                inp = inbuf;
                msdosfs_iconv->convchr(pmp->pm_w2u, __DECONST(const char **,
                    &inp), &ilen, (char **)&outp, &olen);
                len -= olen;

                /*
                 * return '?' if failed to convert
                 */
                if (len == 0)
                        *outp++ = '?';
        } else {
                *outp++ = (wc & 0xff00) ? '?' : (u_char)(wc & 0xff);
        }

        *outp = '\0';
        outp = outbuf;
        return (outp);
}

/*
 * Convert Local char to Windows char
 */
static uint16_t
unix2winchr(const u_char **instr, size_t *ilen, int lower, struct msdosfsmount *pmp)
{
        u_char *outp, outbuf[3];
        uint16_t wc;
        size_t olen;

        if (*ilen == 0)
                return (0);

        if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
                outp = outbuf;
                olen = 2;
                if (lower & (LCASE_BASE | LCASE_EXT))
                        msdosfs_iconv->convchr_case(pmp->pm_u2w, (const char **)instr,
                                                  ilen, (char **)&outp, &olen,
                                                  KICONV_FROM_LOWER);
                else
                        msdosfs_iconv->convchr(pmp->pm_u2w, (const char **)instr,
                                             ilen, (char **)&outp, &olen);

                /*
                 * return '0' if end of filename
                 */
                if (olen == 2)
                        return (0);

                wc = (outbuf[0]<<8) | outbuf[1];

                return (wc);
        }

        (*ilen)--;
        wc = (*instr)[0];
        if (lower & (LCASE_BASE | LCASE_EXT))
                wc = u2l[wc];
        (*instr)++;
        return (wc);
}

/*
 * Initialize the temporary concatenation buffer.
 */
void
mbnambuf_init(struct mbnambuf *nbp)
{

        nbp->nb_len = 0;
        nbp->nb_last_id = -1;
        nbp->nb_buf[sizeof(nbp->nb_buf) - 1] = '\0';
}

/*
 * Fill out our concatenation buffer with the given substring, at the offset
 * specified by its id.  Since this function must be called with ids in
 * descending order, we take advantage of the fact that ASCII substrings are
 * exactly WIN_CHARS in length.  For non-ASCII substrings, we shift all
 * previous (i.e. higher id) substrings upwards to make room for this one.
 * This only penalizes portions of substrings that contain more than
 * WIN_CHARS bytes when they are first encountered.
 */
int
mbnambuf_write(struct mbnambuf *nbp, char *name, int id)
{
        char *slot;
        size_t count, newlen;

        if (nbp->nb_len != 0 && id != nbp->nb_last_id - 1) {
#ifdef MSDOSFS_DEBUG
                printf("msdosfs: non-decreasing id: id %d, last id %d\n",
                    id, nbp->nb_last_id);
#endif
                return (EINVAL);
        }

        /* Will store this substring in a WIN_CHARS-aligned slot. */
        slot = &nbp->nb_buf[id * WIN_CHARS];
        count = strlen(name);
        newlen = nbp->nb_len + count;
        if (newlen > WIN_MAXLEN || newlen > MAXNAMLEN) {
#ifdef MSDOSFS_DEBUG
                printf("msdosfs: file name length %zu too large\n", newlen);
#endif
                return (ENAMETOOLONG);
        }

        /* Shift suffix upwards by the amount length exceeds WIN_CHARS. */
        if (count > WIN_CHARS && nbp->nb_len != 0) {
                if ((id * WIN_CHARS + count + nbp->nb_len) >
                    sizeof(nbp->nb_buf))
                        return (ENAMETOOLONG);

                memmove(slot + count, slot + WIN_CHARS, nbp->nb_len);
        }

        /* Copy in the substring to its slot and update length so far. */
        memcpy(slot, name, count);
        nbp->nb_len = newlen;
        nbp->nb_last_id = id;

        return (0);
}

/*
 * Take the completed string and use it to setup the struct dirent.
 * Be sure to always nul-terminate the d_name and then copy the string
 * from our buffer.  Note that this function assumes the full string has
 * been reassembled in the buffer.  If it's called before all substrings
 * have been written via mbnambuf_write(), the result will be incorrect.
 */
char *
mbnambuf_flush(struct mbnambuf *nbp, struct dirent *dp)
{

        // Haiku port: modified to work with Haiku's struct dirent.
        if (nbp->nb_len > NAME_MAX - 1) {
                mbnambuf_init(nbp);
                return (NULL);
        }
        memcpy(dp->d_name, &nbp->nb_buf[0], nbp->nb_len);
        dp->d_name[nbp->nb_len] = '\0';
        dp->d_reclen = GENERIC_DIRSIZ(dp);

        mbnambuf_init(nbp);
        return (dp->d_name);
}