text: /* $FreeBSD: releng/11.0/sys/fs/msdosfs/msdosfs_conv.c 298806 2016-04-29 20:51:24Z pfg $ */
  /*	$NetBSD: msdosfs_conv.c,v 1.25 1997/11/17 15:36:40 ws Exp $	*/
  
  /*-
   * 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
   */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/dirent.h>
  #include <sys/iconv.h>
  #include <sys/mount.h>
  
  #include <fs/msdosfs/bpb.h>
  #include <fs/msdosfs/direntry.h>
  #include <fs/msdosfs/msdosfsmount.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 u_int16_t unix2doschr(const u_char **, size_t *, struct msdosfsmount *);
  static u_char * win2unixchr(u_char *, u_int16_t, struct msdosfsmount *);
  static u_int16_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 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 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 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 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;
  	u_int16_t c;
  
  	/*
  	 * Fill the dos filename string with blanks. These are DOS's pad
  	 * characters.
  	 */
  	for (i = 0; i < 11; i++)
  		dn[i] = ' ';
  	dn[11] = 0;
  
  	/*
  	 * 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, &i, pmp);
  		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)
  {
  	u_int8_t *wcp;
  	int i, end;
  	u_int16_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
  	 */
  	for (wcp = (u_int8_t *)wep, i = sizeof(*wep); --i >= 0; *wcp++ = 0xff);
  	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 (*un == '\0')
  		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)
  {
  	size_t len;
  	u_int16_t c1, c2;
  	u_char *np;
  	struct dirent dirbuf;
  
  	/*
  	 * We already have winentry in *nbp.
  	 */
  	if (!mbnambuf_flush(nbp, &dirbuf) || dirbuf.d_namlen == 0)
  		return -1;
  
  #ifdef MSDOSFS_DEBUG
  	printf("winChkName(): un=%s:%d,d_name=%s:%d\n", un, unlen,
  							dirbuf.d_name,
  							dirbuf.d_namlen);
  #endif
  
  	/*
  	 * Compare the name parts
  	 */
  	len = dirbuf.d_namlen;
  	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];
  	u_int8_t *cp;
  	u_int8_t *np, name[WIN_CHARS * 3 + 1];
  	u_int16_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.
   */
  u_int8_t
  winChksum(u_int8_t *name)
  {
  	int i;
  	u_int8_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 u_int16_t
  unix2doschr(const u_char **instr, size_t *ilen, struct msdosfsmount *pmp)
  {
  	u_char c;
  	char *up, *outp, unicode[3], outbuf[3];
  	u_int16_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 ((u_int16_t)c);
  }
  
  /*
   * Convert Windows char to Local char
   */
  static u_char *
  win2unixchr(u_char *outbuf, u_int16_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 u_int16_t
  unix2winchr(const u_char **instr, size_t *ilen, int lower, struct msdosfsmount *pmp)
  {
  	u_char *outp, outbuf[3];
  	u_int16_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);
  
  		bcopy(slot + WIN_CHARS, slot + count, nbp->nb_len);
  	}
  
  	/* Copy in the substring to its slot and update length so far. */
  	bcopy(name, slot, 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)
  {
  
  	if (nbp->nb_len > sizeof(dp->d_name) - 1) {
  		mbnambuf_init(nbp);
  		return (NULL);
  	}
  	bcopy(&nbp->nb_buf[0], dp->d_name, nbp->nb_len);
  	dp->d_name[nbp->nb_len] = '\0';
  	dp->d_namlen = nbp->nb_len;
  
  	mbnambuf_init(nbp);
  	return (dp->d_name);
  }
  