sys/fs/msdosfs/msdosfs_conv.c

   1 /*      $NetBSD: msdosfs_conv.c,v 1.10 2014/09/01 09:09:47 martin Exp $ */
   2
   3 /*-
   4  * Copyright (C) 1995, 1997 Wolfgang Solfrank.
   5  * Copyright (C) 1995, 1997 TooLs GmbH.
   6  * All rights reserved.
   7  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by TooLs GmbH.
  20  * 4. The name of TooLs GmbH may not be used to endorse or promote products
  21  *    derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  29  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  31  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  32  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34 /*
  35  * Written by Paul Popelka (paulp@uts.amdahl.com)
  36  *
  37  * You can do anything you want with this software, just don't say you wrote
  38  * it, and don't remove this notice.
  39  *
  40  * This software is provided "as is".
  41  *
  42  * The author supplies this software to be publicly redistributed on the
  43  * understanding that the author is not responsible for the correct
  44  * functioning of this software in any circumstances and is not liable for
  45  * any damages caused by this software.
  46  *
  47  * October 1992
  48  */
  49
  50 #if HAVE_NBTOOL_CONFIG_H
  51 #include "nbtool_config.h"
  52 #endif
  53
  54 #include <sys/cdefs.h>
  55 __KERNEL_RCSID(0, "$NetBSD: msdosfs_conv.c,v 1.10 2014/09/01 09:09:47 martin Exp $");
  56
  57 /*
  58  * System include files.
  59  */
  60 #include <sys/param.h>
  61 #include <sys/time.h>
  62 #ifdef _KERNEL
  63 #include <sys/dirent.h>
  64 #include <sys/systm.h>
  65 #include <sys/kernel.h>
  66 #include <sys/vnode.h>
  67 #else
  68 #include <stdio.h>
  69 #include <string.h>
  70 #include <dirent.h>
  71 #include <sys/queue.h>
  72 #endif
  73 #include <dev/clock_subr.h>
  74
  75 /*
  76  * MSDOSFS include files.
  77  */
  78 #include <fs/msdosfs/direntry.h>
  79 #include <fs/msdosfs/denode.h>
  80
  81 /*
  82  * The number of seconds between Jan 1, 1970 and Jan 1, 1980. In that
  83  * interval there were 8 regular years and 2 leap years.
  84  */
  85 #define DOSBIASYEAR     1980
  86 #define SECONDSTO1980   (((8 * 365) + (2 * 366)) * (24 * 60 * 60))
  87 /*
  88  * msdos fs can not store dates beyound the year 2234
  89  */
  90 #define DOSMAXYEAR      ((DD_YEAR_MASK >> DD_YEAR_SHIFT) + DOSBIASYEAR)
  91
  92 /*
  93  * Convert the unix version of time to dos's idea of time to be used in
  94  * file timestamps. The passed in unix time is assumed to be in GMT.
  95  */
  96 void
  97 unix2dostime(const struct timespec *tsp, int gmtoff, u_int16_t *ddp, u_int16_t *dtp, u_int8_t *dhp)
  98 {
  99         u_long t;
 100         struct clock_ymdhms ymd;
 101
 102         t = tsp->tv_sec + gmtoff; /* time zone correction */
 103
 104         /*
 105          * DOS timestamps can not represent dates before 1980.
 106          */
 107         if (t < SECONDSTO1980)
 108                 goto invalid_dos_date;
 109
 110         /*
 111          * DOS granularity is 2 seconds
 112          */
 113         t &= ~1;
 114
 115         /*
 116          * Convert to year/month/day/.. format
 117          */
 118         clock_secs_to_ymdhms(t, &ymd);
 119         if (ymd.dt_year > DOSMAXYEAR)
 120                 goto invalid_dos_date;
 121
 122         /*
 123          * Now transform to DOS format
 124          */
 125         *ddp = (ymd.dt_day << DD_DAY_SHIFT)
 126             + (ymd.dt_mon << DD_MONTH_SHIFT)
 127             + ((ymd.dt_year - DOSBIASYEAR) << DD_YEAR_SHIFT);
 128         if (dhp)
 129                 *dhp = (tsp->tv_sec & 1) * 100 + tsp->tv_nsec / 10000000;
 130         if (dtp)
 131                 *dtp = (((t / 2) % 30) << DT_2SECONDS_SHIFT)
 132                     + (((t / 60) % 60) << DT_MINUTES_SHIFT)
 133                     + (((t / 3600) % 24) << DT_HOURS_SHIFT);
 134         return;
 135
 136 invalid_dos_date:
 137         *ddp = 0;
 138         if (dtp)
 139                 *dtp = 0;
 140         if (dhp)
 141                 *dhp = 0;
 142 }
 143
 144 /*
 145  * Convert from dos' idea of time to unix'. This will probably only be
 146  * called from the stat(), and fstat() system calls and so probably need
 147  * not be too efficient.
 148  */
 149 void
 150 dos2unixtime(u_int dd, u_int dt, u_int dh, int gmtoff, struct timespec *tsp)
 151 {
 152         time_t seconds;
 153         struct clock_ymdhms ymd;
 154
 155         if (dd == 0) {
 156                 /*
 157                  * Uninitialized field, return the epoch.
 158                  */
 159                 tsp->tv_sec = 0;
 160                 tsp->tv_nsec = 0;
 161                 return;
 162         }
 163
 164         memset(&ymd, 0, sizeof(ymd));
 165         ymd.dt_year = ((dd & DD_YEAR_MASK) >> DD_YEAR_SHIFT) + 1980 ;
 166         ymd.dt_mon = ((dd & DD_MONTH_MASK) >> DD_MONTH_SHIFT);
 167         ymd.dt_day = ((dd & DD_DAY_MASK) >> DD_DAY_SHIFT);
 168         ymd.dt_hour = (dt & DT_HOURS_MASK) >> DT_HOURS_SHIFT;
 169         ymd.dt_min = (dt & DT_MINUTES_MASK) >> DT_MINUTES_SHIFT;
 170         ymd.dt_sec = ((dt & DT_2SECONDS_MASK) >> DT_2SECONDS_SHIFT) * 2;
 171
 172         seconds = clock_ymdhms_to_secs(&ymd);
 173
 174         tsp->tv_sec = seconds;
 175         tsp->tv_sec -= gmtoff;  /* time zone correction */
 176         tsp->tv_nsec = (dh % 100) * 10000000;
 177 }
 178
 179 static const u_char
 180 unix2dos[256] = {
 181         0,    0,    0,    0,    0,    0,    0,    0,    /* 00-07 */
 182         0,    0,    0,    0,    0,    0,    0,    0,    /* 08-0f */
 183         0,    0,    0,    0,    0,    0,    0,    0,    /* 10-17 */
 184         0,    0,    0,    0,    0,    0,    0,    0,    /* 18-1f */
 185         0,    '!',  0,    '#',  '$',  '%',  '&',  '\'', /* 20-27 */
 186         '(',  ')',  0,    '+',  0,    '-',  0,    0,    /* 28-2f */
 187         '0',  '1',  '2',  '3',  '4',  '5',  '6',  '7',  /* 30-37 */
 188         '8',  '9',  0,    0,    0,    0,    0,    0,    /* 38-3f */
 189         '@',  'A',  'B',  'C',  'D',  'E',  'F',  'G',  /* 40-47 */
 190         'H',  'I',  'J',  'K',  'L',  'M',  'N',  'O',  /* 48-4f */
 191         'P',  'Q',  'R',  'S',  'T',  'U',  'V',  'W',  /* 50-57 */
 192         'X',  'Y',  'Z',  0,    0,    0,    '^',  '_',  /* 58-5f */
 193         '`',  'A',  'B',  'C',  'D',  'E',  'F',  'G',  /* 60-67 */
 194         'H',  'I',  'J',  'K',  'L',  'M',  'N',  'O',  /* 68-6f */
 195         'P',  'Q',  'R',  'S',  'T',  'U',  'V',  'W',  /* 70-77 */
 196         'X',  'Y',  'Z',  '{',  0,    '}',  '~',  0,    /* 78-7f */
 197         0,    0,    0,    0,    0,    0,    0,    0,    /* 80-87 */
 198         0,    0,    0,    0,    0,    0,    0,    0,    /* 88-8f */
 199         0,    0,    0,    0,    0,    0,    0,    0,    /* 90-97 */
 200         0,    0,    0,    0,    0,    0,    0,    0,    /* 98-9f */
 201         0,    0xad, 0xbd, 0x9c, 0xcf, 0xbe, 0xdd, 0xf5, /* a0-a7 */
 202         0xf9, 0xb8, 0xa6, 0xae, 0xaa, 0xf0, 0xa9, 0xee, /* a8-af */
 203         0xf8, 0xf1, 0xfd, 0xfc, 0xef, 0xe6, 0xf4, 0xfa, /* b0-b7 */
 204         0xf7, 0xfb, 0xa7, 0xaf, 0xac, 0xab, 0xf3, 0xa8, /* b8-bf */
 205         0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* c0-c7 */
 206         0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* c8-cf */
 207         0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0x9e, /* d0-d7 */
 208         0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0xe1, /* d8-df */
 209         0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* e0-e7 */
 210         0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* e8-ef */
 211         0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0xf6, /* f0-f7 */
 212         0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0x98, /* f8-ff */
 213 };
 214
 215 static const u_char
 216 dos2unix[256] = {
 217          '?',  '?',  '?',  '?',  '?',  '?',  '?',  '?', /* 00-07 */
 218          '?',  '?',  '?',  '?',  '?',  '?',  '?',  '?', /* 08-0f */
 219          '?',  '?',  '?',  '?',  '?',  '?',  '?',  '?', /* 10-17 */
 220          '?',  '?',  '?',  '?',  '?',  '?',  '?',  '?', /* 18-1f */
 221          ' ',  '!',  '"',  '#',  '$',  '%',  '&', '\'', /* 20-27 */
 222          '(',  ')',  '*',  '+',  ',',  '-',  '.',  '/', /* 28-2f */
 223          '0',  '1',  '2',  '3',  '4',  '5',  '6',  '7', /* 30-37 */
 224          '8',  '9',  ':',  ';',  '<',  '=',  '>',  '?', /* 38-3f */
 225          '@',  'A',  'B',  'C',  'D',  'E',  'F',  'G', /* 40-47 */
 226          'H',  'I',  'J',  'K',  'L',  'M',  'N',  'O', /* 48-4f */
 227          'P',  'Q',  'R',  'S',  'T',  'U',  'V',  'W', /* 50-57 */
 228          'X',  'Y',  'Z',  '[', '\\',  ']',  '^',  '_', /* 58-5f */
 229          '`',  'a',  'b',  'c',  'd',  'e',  'f',  'g', /* 60-67 */
 230          'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o', /* 68-6f */
 231          'p',  'q',  'r',  's',  't',  'u',  'v',  'w', /* 70-77 */
 232          'x',  'y',  'z',  '{',  '|',  '}',  '~', 0x7f, /* 78-7f */
 233         0xc7, 0xfc, 0xe9, 0xe2, 0xe4, 0xe0, 0xe5, 0xe7, /* 80-87 */
 234         0xea, 0xeb, 0xe8, 0xef, 0xee, 0xec, 0xc4, 0xc5, /* 88-8f */
 235         0xc9, 0xe6, 0xc6, 0xf4, 0xf6, 0xf2, 0xfb, 0xf9, /* 90-97 */
 236         0xff, 0xd6, 0xdc, 0xf8, 0xa3, 0xd8, 0xd7,  '?', /* 98-9f */
 237         0xe1, 0xed, 0xf3, 0xfa, 0xf1, 0xd1, 0xaa, 0xba, /* a0-a7 */
 238         0xbf, 0xae, 0xac, 0xbd, 0xbc, 0xa1, 0xab, 0xbb, /* a8-af */
 239          '?',  '?',  '?',  '?',  '?', 0xc1, 0xc2, 0xc0, /* b0-b7 */
 240         0xa9,  '?',  '?',  '?',  '?', 0xa2, 0xa5,  '?', /* b8-bf */
 241          '?',  '?',  '?',  '?',  '?',  '?', 0xe3, 0xc3, /* c0-c7 */
 242          '?',  '?',  '?',  '?',  '?',  '?',  '?', 0xa4, /* c8-cf */
 243         0xf0, 0xd0, 0xca, 0xcb, 0xc8,  '?', 0xcd, 0xce, /* d0-d7 */
 244         0xcf,  '?',  '?',  '?',  '?', 0xa6, 0xcc,  '?', /* d8-df */
 245         0xd3, 0xdf, 0xd4, 0xd2, 0xf5, 0xd5, 0xb5, 0xfe, /* e0-e7 */
 246         0xde, 0xda, 0xdb, 0xd9, 0xfd, 0xdd, 0xaf, 0x3f, /* e8-ef */
 247         0xad, 0xb1,  '?', 0xbe, 0xb6, 0xa7, 0xf7, 0xb8, /* f0-f7 */
 248         0xb0, 0xa8, 0xb7, 0xb9, 0xb3, 0xb2,  '?',  '?', /* f8-ff */
 249 };
 250
 251 static const u_char
 252 u2l[256] = {
 253         0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 00-07 */
 254         0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 08-0f */
 255         0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 10-17 */
 256         0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 18-1f */
 257          ' ',  '!',  '"',  '#',  '$',  '%',  '&', '\'', /* 20-27 */
 258          '(',  ')',  '*',  '+',  ',',  '-',  '.',  '/', /* 28-2f */
 259          '0',  '1',  '2',  '3',  '4',  '5',  '6',  '7', /* 30-37 */
 260          '8',  '9',  ':',  ';',  '<',  '=',  '>',  '?', /* 38-3f */
 261          '@',  'a',  'b',  'c',  'd',  'e',  'f',  'g', /* 40-47 */
 262          'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o', /* 48-4f */
 263          'p',  'q',  'r',  's',  't',  'u',  'v',  'w', /* 50-57 */
 264          'x',  'y',  'z',  '[', '\\',  ']',  '^',  '_', /* 58-5f */
 265          '`',  'a',  'b',  'c',  'd',  'e',  'f',  'g', /* 60-67 */
 266          'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o', /* 68-6f */
 267          'p',  'q',  'r',  's',  't',  'u',  'v',  'w', /* 70-77 */
 268          'x',  'y',  'z',  '{',  '|',  '}',  '~', 0x7f, /* 78-7f */
 269         0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 80-87 */
 270         0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 88-8f */
 271         0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 90-97 */
 272         0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 98-9f */
 273         0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* a0-a7 */
 274         0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* a8-af */
 275         0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* b0-b7 */
 276         0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* b8-bf */
 277         0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* c0-c7 */
 278         0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* c8-cf */
 279         0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xd7, /* d0-d7 */
 280         0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xdf, /* d8-df */
 281         0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* e0-e7 */
 282         0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* e8-ef */
 283         0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* f0-f7 */
 284         0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* f8-ff */
 285 };
 286
 287 /*
 288  * DOS filenames are made of 2 parts, the name part and the extension part.
 289  * The name part is 8 characters long and the extension part is 3
 290  * characters long.  They may contain trailing blanks if the name or
 291  * extension are not long enough to fill their respective fields.
 292  */
 293
 294 /*
 295  * Convert a DOS filename to a unix filename. And, return the number of
 296  * characters in the resulting unix filename excluding the terminating
 297  * null.
 298  */
 299 int
 300 dos2unixfn(u_char dn[11], u_char *un, int lower)
 301 {
 302         int i, j;
 303         int thislong = 1;
 304         u_char c;
 305
 306         /*
 307          * If first char of the filename is SLOT_E5 (0x05), then the real
 308          * first char of the filename should be 0xe5. But, they couldn't
 309          * just have a 0xe5 mean 0xe5 because that is used to mean a freed
 310          * directory slot. Another dos quirk.
 311          */
 312         if (*dn == SLOT_E5)
 313                 c = dos2unix[0xe5];
 314         else
 315                 c = dos2unix[*dn];
 316         *un++ = lower ? u2l[c] : c;
 317
 318         /*
 319          * Copy the rest into the unix filename string, ignoring
 320          * trailing blanks.
 321          */
 322
 323         for (j=7; (j >= 0) && (dn[j] == ' '); j--)
 324                 ;
 325
 326         for (i = 1; i <= j; i++) {
 327                 c = dos2unix[dn[i]];
 328                 *un++ = lower ? u2l[c] : c;
 329                 thislong++;
 330         }
 331         dn += 8;
 332
 333         /*
 334          * Now, if there is an extension then put in a period and copy in
 335          * the extension.
 336          */
 337         if (*dn != ' ') {
 338                 *un++ = '.';
 339                 thislong++;
 340                 for (i = 0; i < 3 && *dn != ' '; i++) {
 341                         c = dos2unix[*dn++];
 342                         *un++ = lower ? u2l[c] : c;
 343                         thislong++;
 344                 }
 345         }
 346         *un++ = 0;
 347
 348         return (thislong);
 349 }
 350
 351 /*
 352  * Convert a unix filename to a DOS filename according to Win95 rules.
 353  * If applicable and gen is not 0, it is inserted into the converted
 354  * filename as a generation number.
 355  * Returns
 356  *      0 if name couldn't be converted
 357  *      1 if the converted name is the same as the original
 358  *        (no long filename entry necessary for Win95)
 359  *      2 if conversion was successful
 360  *      3 if conversion was successful and generation number was inserted
 361  */
 362 int
 363 unix2dosfn(const u_char *un, u_char dn[12], int unlen, u_int gen)
 364 {
 365         int i, j, l;
 366         int conv = 1;
 367         const u_char *cp, *dp, *dp1;
 368         u_char gentext[6], *wcp;
 369         int shortlen;
 370
 371         /*
 372          * Fill the dos filename string with blanks. These are DOS's pad
 373          * characters.
 374          */
 375         for (i = 0; i < 11; i++)
 376                 dn[i] = ' ';
 377         dn[11] = 0;
 378
 379         /*
 380          * The filenames "." and ".." are handled specially, since they
 381          * don't follow dos filename rules.
 382          */
 383         if (un[0] == '.' && unlen == 1) {
 384                 dn[0] = '.';
 385                 return gen <= 1;
 386         }
 387         if (un[0] == '.' && un[1] == '.' && unlen == 2) {
 388                 dn[0] = '.';
 389                 dn[1] = '.';
 390                 return gen <= 1;
 391         }
 392
 393         /*
 394          * Filenames with only blanks and dots are not allowed!
 395          */
 396         for (cp = un, i = unlen; --i >= 0; cp++)
 397                 if (*cp != ' ' && *cp != '.')
 398                         break;
 399         if (i < 0)
 400                 return 0;
 401
 402         /*
 403          * Now find the extension
 404          * Note: dot as first char doesn't start extension
 405          *       and trailing dots and blanks are ignored
 406          */
 407         dp = dp1 = 0;
 408         for (cp = un + 1, i = unlen - 1; --i >= 0;) {
 409                 switch (*cp++) {
 410                 case '.':
 411                         if (!dp1)
 412                                 dp1 = cp;
 413                         break;
 414                 case ' ':
 415                         break;
 416                 default:
 417                         if (dp1)
 418                                 dp = dp1;
 419                         dp1 = 0;
 420                         break;
 421                 }
 422         }
 423
 424         /*
 425          * Now convert it
 426          */
 427         if (dp) {
 428                 if (dp1)
 429                         l = dp1 - dp;
 430                 else
 431                         l = unlen - (dp - un);
 432                 for (i = 0, j = 8; i < l && j < 11; i++, j++) {
 433                         if (dp[i] != (dn[j] = unix2dos[dp[i]])
 434                             && conv != 3)
 435                                 conv = 2;
 436                         if (!dn[j]) {
 437                                 conv = 3;
 438                                 dn[j--] = ' ';
 439                         }
 440                 }
 441                 if (i < l)
 442                         conv = 3;
 443                 dp--;
 444         } else {
 445                 for (dp = cp; *--dp == ' ' || *dp == '.';);
 446                 dp++;
 447         }
 448
 449         shortlen = (dp - un) <= 8;
 450
 451         /*
 452          * Now convert the rest of the name
 453          */
 454         for (i = j = 0; un < dp && j < 8; i++, j++, un++) {
 455                 if ((*un == ' ') && shortlen)
 456                         dn[j] = ' ';
 457                 else
 458                         dn[j] = unix2dos[*un];
 459                 if ((*un != dn[j])
 460                     && conv != 3)
 461                         conv = 2;
 462                 if (!dn[j]) {
 463                         conv = 3;
 464                         dn[j--] = ' ';
 465                 }
 466         }
 467         if (un < dp)
 468                 conv = 3;
 469         /*
 470          * If we didn't have any chars in filename,
 471          * generate a default
 472          */
 473         if (!j)
 474                 dn[0] = '_';
 475
 476         /*
 477          * The first character cannot be E5,
 478          * because that means a deleted entry
 479          */
 480         if (dn[0] == 0xe5)
 481                 dn[0] = SLOT_E5;
 482
 483         /*
 484          * If there wasn't any char dropped,
 485          * there is no place for generation numbers
 486          */
 487         if (conv != 3) {
 488                 if (gen > 1)
 489                         return 0;
 490                 return conv;
 491         }
 492
 493         /*
 494          * Now insert the generation number into the filename part
 495          */
 496         for (wcp = gentext + sizeof(gentext); wcp > gentext && gen; gen /= 10)
 497                 *--wcp = gen % 10 + '0';
 498         if (gen)
 499                 return 0;
 500         for (i = 8; dn[--i] == ' ';);
 501         i++;
 502         if (gentext + sizeof(gentext) - wcp + 1 > 8 - i)
 503                 i = 8 - (gentext + sizeof(gentext) - wcp + 1);
 504         dn[i++] = '~';
 505         while (wcp < gentext + sizeof(gentext))
 506                 dn[i++] = *wcp++;
 507         return 3;
 508 }
 509
 510 /*
 511  * Create a Win95 long name directory entry
 512  * Note: assumes that the filename is valid,
 513  *       i.e. doesn't consist solely of blanks and dots
 514  */
 515 int
 516 unix2winfn(const u_char *un, int unlen, struct winentry *wep, int cnt, int chksum)
 517 {
 518         const u_int8_t *cp;
 519         u_int8_t *wcp;
 520         int i;
 521
 522         /*
 523          * Drop trailing blanks and dots
 524          */
 525         for (cp = un + unlen; *--cp == ' ' || *cp == '.'; unlen--);
 526
 527         un += (cnt - 1) * WIN_CHARS;
 528         unlen -= (cnt - 1) * WIN_CHARS;
 529
 530         /*
 531          * Initialize winentry to some useful default
 532          */
 533         for (wcp = (u_int8_t *)wep, i = sizeof(*wep); --i >= 0; *wcp++ = 0xff);
 534         wep->weCnt = cnt;
 535         wep->weAttributes = ATTR_WIN95;
 536         wep->weReserved1 = 0;
 537         wep->weChksum = chksum;
 538         wep->weReserved2 = 0;
 539
 540         /*
 541          * Now convert the filename parts
 542          */
 543         for (wcp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
 544                 if (--unlen < 0)
 545                         goto done;
 546                 *wcp++ = *un++;
 547                 *wcp++ = 0;
 548         }
 549         for (wcp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
 550                 if (--unlen < 0)
 551                         goto done;
 552                 *wcp++ = *un++;
 553                 *wcp++ = 0;
 554         }
 555         for (wcp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
 556                 if (--unlen < 0)
 557                         goto done;
 558                 *wcp++ = *un++;
 559                 *wcp++ = 0;
 560         }
 561         if (!unlen)
 562                 wep->weCnt |= WIN_LAST;
 563         return unlen;
 564
 565 done:
 566         *wcp++ = 0;
 567         *wcp++ = 0;
 568         wep->weCnt |= WIN_LAST;
 569         return 0;
 570 }
 571
 572 /*
 573  * Compare our filename to the one in the Win95 entry
 574  * Returns the checksum or -1 if no match
 575  */
 576 int
 577 winChkName(const u_char *un, int unlen, struct winentry *wep, int chksum)
 578 {
 579         u_int8_t *cp;
 580         int i;
 581
 582         /*
 583          * First compare checksums
 584          */
 585         if (wep->weCnt&WIN_LAST)
 586                 chksum = wep->weChksum;
 587         else if (chksum != wep->weChksum)
 588                 chksum = -1;
 589         if (chksum == -1)
 590                 return -1;
 591
 592         /*
 593          * Offset of this entry
 594          */
 595         i = ((wep->weCnt&WIN_CNT) - 1) * WIN_CHARS;
 596         un += i;
 597         if ((unlen -= i) < 0)
 598                 return -1;
 599
 600         /*
 601          * Ignore redundant winentries (those with only \0\0 on start in them).
 602          * An appearance of such entry is a bug; unknown if in NetBSD msdosfs
 603          * or MS Windows.
 604          */
 605         if (unlen == 0) {
 606                 if (wep->wePart1[0] == '\0' && wep->wePart1[1] == '\0')
 607                         return chksum;
 608                 else
 609                         return -1;
 610         }
 611
 612         if ((wep->weCnt&WIN_LAST) && unlen > WIN_CHARS)
 613                 return -1;
 614
 615         /*
 616          * Compare the name parts
 617          */
 618         for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
 619                 if (--unlen < 0) {
 620                         if (!*cp++ && !*cp)
 621                                 return chksum;
 622                         return -1;
 623                 }
 624                 if (u2l[*cp++] != u2l[*un++] || *cp++)
 625                         return -1;
 626         }
 627         for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
 628                 if (--unlen < 0) {
 629                         if (!*cp++ && !*cp)
 630                                 return chksum;
 631                         return -1;
 632                 }
 633                 if (u2l[*cp++] != u2l[*un++] || *cp++)
 634                         return -1;
 635         }
 636         for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
 637                 if (--unlen < 0) {
 638                         if (!*cp++ && !*cp)
 639                                 return chksum;
 640                         return -1;
 641                 }
 642                 if (u2l[*cp++] != u2l[*un++] || *cp++)
 643                         return -1;
 644         }
 645         return chksum;
 646 }
 647
 648 /*
 649  * Convert Win95 filename to dirbuf.
 650  * Returns the checksum or -1 if impossible
 651  */
 652 int
 653 win2unixfn(struct winentry *wep, struct dirent *dp, int chksum)
 654 {
 655         u_int8_t *cp;
 656         u_int8_t *np, *ep = (u_int8_t *)dp->d_name + WIN_MAXLEN;
 657         int i;
 658
 659         if ((wep->weCnt&WIN_CNT) > howmany(WIN_MAXLEN, WIN_CHARS)
 660             || !(wep->weCnt&WIN_CNT))
 661                 return -1;
 662
 663         /*
 664          * First compare checksums
 665          */
 666         if (wep->weCnt&WIN_LAST) {
 667                 chksum = wep->weChksum;
 668                 /*
 669                  * This works even though d_namlen is one byte!
 670                  */
 671 #ifdef __NetBSD__
 672                 dp->d_namlen = (wep->weCnt&WIN_CNT) * WIN_CHARS;
 673 #endif
 674         } else if (chksum != wep->weChksum)
 675                 chksum = -1;
 676         if (chksum == -1)
 677                 return -1;
 678
 679         /*
 680          * Offset of this entry
 681          */
 682         i = ((wep->weCnt&WIN_CNT) - 1) * WIN_CHARS;
 683         np = (u_int8_t *)dp->d_name + i;
 684
 685         /*
 686          * Convert the name parts
 687          */
 688         for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
 689                 switch (*np++ = *cp++) {
 690                 case 0:
 691 #ifdef __NetBSD__
 692                         dp->d_namlen -= sizeof(wep->wePart2)/2
 693                             + sizeof(wep->wePart3)/2 + i + 1;
 694 #endif
 695                         return chksum;
 696                 case '/':
 697                         np[-1] = 0;
 698                         return -1;
 699                 }
 700                 /*
 701                  * The size comparison should result in the compiler
 702                  * optimizing the whole if away
 703                  */
 704                 if (WIN_MAXLEN % WIN_CHARS < sizeof(wep->wePart1) / 2
 705                     && np > ep) {
 706                         np[-1] = 0;
 707                         return -1;
 708                 }
 709                 if (*cp++)
 710                         return -1;
 711         }
 712         for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
 713                 switch (*np++ = *cp++) {
 714                 case 0:
 715 #ifdef __NetBSD__
 716                         dp->d_namlen -= sizeof(wep->wePart3)/2 + i + 1;
 717 #endif
 718                         return chksum;
 719                 case '/':
 720                         np[-1] = 0;
 721                         return -1;
 722                 }
 723                 /*
 724                  * The size comparisons should be optimized away
 725                  */
 726                 if (WIN_MAXLEN % WIN_CHARS >= sizeof(wep->wePart1) / 2
 727                     && WIN_MAXLEN % WIN_CHARS < (sizeof(wep->wePart1) + sizeof(wep->wePart2)) / 2
 728                     && np > ep) {
 729                         np[-1] = 0;
 730                         return -1;
 731                 }
 732                 if (*cp++)
 733                         return -1;
 734         }
 735         for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
 736                 switch (*np++ = *cp++) {
 737                 case 0:
 738 #ifdef __NetBSD__
 739                         dp->d_namlen -= i + 1;
 740 #endif
 741                         return chksum;
 742                 case '/':
 743                         np[-1] = 0;
 744                         return -1;
 745                 }
 746                 /*
 747                  * See above
 748                  */
 749                 if (WIN_MAXLEN % WIN_CHARS >= (sizeof(wep->wePart1) + sizeof(wep->wePart2)) / 2
 750                     && np > ep) {
 751                         np[-1] = 0;
 752                         return -1;
 753                 }
 754                 if (*cp++)
 755                         return -1;
 756         }
 757         return chksum;
 758 }
 759
 760 /*
 761  * Compute the checksum of a DOS filename for Win95 use
 762  */
 763 u_int8_t
 764 winChksum(u_int8_t *name)
 765 {
 766         int i;
 767         u_int8_t s;
 768
 769         for (s = 0, i = 11; --i >= 0; s += *name++)
 770                 s = (s << 7)|(s >> 1);
 771         return s;
 772 }
 773
 774 /*
 775  * Determine the number of slots necessary for Win95 names
 776  */
 777 int
 778 winSlotCnt(const u_char *un, int unlen)
 779 {
 780         for (un += unlen; unlen > 0; unlen--)
 781                 if (*--un != ' ' && *un != '.')
 782                         break;
 783         if (unlen > WIN_MAXLEN)
 784                 return 0;
 785         return howmany(unlen, WIN_CHARS);
 786 }