reactos/drivers/fs/ntfs/linux-ntfs/unistr.c

   1 /*
   2  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
   3  *
   4  * Copyright (c) 2001-2003 Anton Altaparmakov
   5  *
   6  * This program/include file is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as published
   8  * by the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program/include file is distributed in the hope that it will be
  12  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program (in the main directory of the Linux-NTFS
  18  * distribution in the file COPYING); if not, write to the Free Software
  19  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include "ntfs.h"
  23
  24 /*
  25  * IMPORTANT
  26  * =========
  27  *
  28  * All these routines assume that the Unicode characters are in little endian
  29  * encoding inside the strings!!!
  30  */
  31
  32 /*
  33  * This is used by the name collation functions to quickly determine what
  34  * characters are (in)valid.
  35  */
  36 static const u8 legal_ansi_char_array[0x40] = {
  37         0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  38         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  39
  40         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  41         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  42
  43         0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
  44         0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
  45
  46         0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
  47         0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
  48 };
  49
  50 /**
  51  * ntfs_are_names_equal - compare two Unicode names for equality
  52  * @s1:                 name to compare to @s2
  53  * @s1_len:             length in Unicode characters of @s1
  54  * @s2:                 name to compare to @s1
  55  * @s2_len:             length in Unicode characters of @s2
  56  * @ic:                 ignore case bool
  57  * @upcase:             upcase table (only if @ic == IGNORE_CASE)
  58  * @upcase_size:        length in Unicode characters of @upcase (if present)
  59  *
  60  * Compare the names @s1 and @s2 and return TRUE (1) if the names are
  61  * identical, or FALSE (0) if they are not identical. If @ic is IGNORE_CASE,
  62  * the @upcase table is used to performa a case insensitive comparison.
  63  */
  64 BOOL ntfs_are_names_equal(const uchar_t *s1, size_t s1_len,
  65                      const uchar_t *s2, size_t s2_len,
  66                      const IGNORE_CASE_BOOL ic,
  67                      const uchar_t *upcase, const u32 upcase_size)
  68 {
  69         if (s1_len != s2_len)
  70                 return FALSE;
  71         if (ic == CASE_SENSITIVE)
  72                 return !ntfs_ucsncmp(s1, s2, s1_len);
  73         return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
  74 }
  75
  76 /**
  77  * ntfs_collate_names - collate two Unicode names
  78  * @name1:      first Unicode name to compare
  79  * @name2:      second Unicode name to compare
  80  * @err_val:    if @name1 contains an invalid character return this value
  81  * @ic:         either CASE_SENSITIVE or IGNORE_CASE
  82  * @upcase:     upcase table (ignored if @ic is CASE_SENSITIVE)
  83  * @upcase_len: upcase table size (ignored if @ic is CASE_SENSITIVE)
  84  *
  85  * ntfs_collate_names collates two Unicode names and returns:
  86  *
  87  *  -1 if the first name collates before the second one,
  88  *   0 if the names match,
  89  *   1 if the second name collates before the first one, or
  90  * @err_val if an invalid character is found in @name1 during the comparison.
  91  *
  92  * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
  93  */
  94 int ntfs_collate_names(const uchar_t *name1, const u32 name1_len,
  95                 const uchar_t *name2, const u32 name2_len,
  96                 const int err_val, const IGNORE_CASE_BOOL ic,
  97                 const uchar_t *upcase, const u32 upcase_len)
  98 {
  99         u32 cnt, min_len;
 100         uchar_t c1, c2;
 101
 102         min_len = name1_len;
 103         if (name1_len > name2_len)
 104                 min_len = name2_len;
 105         for (cnt = 0; cnt < min_len; ++cnt) {
 106                 c1 = le16_to_cpu(*name1++);
 107                 c2 = le16_to_cpu(*name2++);
 108                 if (ic) {
 109                         if (c1 < upcase_len)
 110                                 c1 = le16_to_cpu(upcase[c1]);
 111                         if (c2 < upcase_len)
 112                                 c2 = le16_to_cpu(upcase[c2]);
 113                 }
 114                 if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 115                         return err_val;
 116                 if (c1 < c2)
 117                         return -1;
 118                 if (c1 > c2)
 119                         return 1;
 120         }
 121         if (name1_len < name2_len)
 122                 return -1;
 123         if (name1_len == name2_len)
 124                 return 0;
 125         /* name1_len > name2_len */
 126         c1 = le16_to_cpu(*name1);
 127         if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 128                 return err_val;
 129         return 1;
 130 }
 131
 132 /**
 133  * ntfs_ucsncmp - compare two little endian Unicode strings
 134  * @s1:         first string
 135  * @s2:         second string
 136  * @n:          maximum unicode characters to compare
 137  *
 138  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 139  * The strings in little endian format and appropriate le16_to_cpu()
 140  * conversion is performed on non-little endian machines.
 141  *
 142  * The function returns an integer less than, equal to, or greater than zero
 143  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 144  * to be less than, to match, or be greater than @s2.
 145  */
 146 int ntfs_ucsncmp(const uchar_t *s1, const uchar_t *s2, size_t n)
 147 {
 148         uchar_t c1, c2;
 149         size_t i;
 150
 151         for (i = 0; i < n; ++i) {
 152                 c1 = le16_to_cpu(s1[i]);
 153                 c2 = le16_to_cpu(s2[i]);
 154                 if (c1 < c2)
 155                         return -1;
 156                 if (c1 > c2)
 157                         return 1;
 158                 if (!c1)
 159                         break;
 160         }
 161         return 0;
 162 }
 163
 164 /**
 165  * ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
 166  * @s1:                 first string
 167  * @s2:                 second string
 168  * @n:                  maximum unicode characters to compare
 169  * @upcase:             upcase table
 170  * @upcase_size:        upcase table size in Unicode characters
 171  *
 172  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 173  * ignoring case. The strings in little endian format and appropriate
 174  * le16_to_cpu() conversion is performed on non-little endian machines.
 175  *
 176  * Each character is uppercased using the @upcase table before the comparison.
 177  *
 178  * The function returns an integer less than, equal to, or greater than zero
 179  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 180  * to be less than, to match, or be greater than @s2.
 181  */
 182 int ntfs_ucsncasecmp(const uchar_t *s1, const uchar_t *s2, size_t n,
 183                      const uchar_t *upcase, const u32 upcase_size)
 184 {
 185         uchar_t c1, c2;
 186         size_t i;
 187
 188         for (i = 0; i < n; ++i) {
 189                 if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
 190                         c1 = le16_to_cpu(upcase[c1]);
 191                 if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
 192                         c2 = le16_to_cpu(upcase[c2]);
 193                 if (c1 < c2)
 194                         return -1;
 195                 if (c1 > c2)
 196                         return 1;
 197                 if (!c1)
 198                         break;
 199         }
 200         return 0;
 201 }
 202
 203 void ntfs_upcase_name(uchar_t *name, u32 name_len, const uchar_t *upcase,
 204                 const u32 upcase_len)
 205 {
 206         u32 i;
 207         uchar_t u;
 208
 209         for (i = 0; i < name_len; i++)
 210                 if ((u = le16_to_cpu(name[i])) < upcase_len)
 211                         name[i] = upcase[u];
 212 }
 213
 214 void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
 215                 const uchar_t *upcase, const u32 upcase_len)
 216 {
 217         ntfs_upcase_name((uchar_t*)&file_name_attr->file_name,
 218                         file_name_attr->file_name_length, upcase, upcase_len);
 219 }
 220
 221 int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
 222                 FILE_NAME_ATTR *file_name_attr2,
 223                 const int err_val, const IGNORE_CASE_BOOL ic,
 224                 const uchar_t *upcase, const u32 upcase_len)
 225 {
 226         return ntfs_collate_names((uchar_t*)&file_name_attr1->file_name,
 227                         file_name_attr1->file_name_length,
 228                         (uchar_t*)&file_name_attr2->file_name,
 229                         file_name_attr2->file_name_length,
 230                         err_val, ic, upcase, upcase_len);
 231 }
 232
 233 /**
 234  * ntfs_nlstoucs - convert NLS string to little endian Unicode string
 235  * @vol:        ntfs volume which we are working with
 236  * @ins:        input NLS string buffer
 237  * @ins_len:    length of input string in bytes
 238  * @outs:       on return contains the allocated output Unicode string buffer
 239  *
 240  * Convert the input string @ins, which is in whatever format the loaded NLS
 241  * map dictates, into a little endian, 2-byte Unicode string.
 242  *
 243  * This function allocates the string and the caller is responsible for
 244  * calling kmem_cache_free(ntfs_name_cache, @outs); when finished with it.
 245  *
 246  * On success the function returns the number of Unicode characters written to
 247  * the output string *@outs (>= 0), not counting the terminating Unicode NULL
 248  * character. *@outs is set to the allocated output string buffer.
 249  *
 250  * On error, a negative number corresponding to the error code is returned. In
 251  * that case the output string is not allocated. Both *@outs and *@outs_len
 252  * are then undefined.
 253  *
 254  * This might look a bit odd due to fast path optimization...
 255  */
 256 int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
 257                 const int ins_len, uchar_t **outs)
 258 {
 259         struct nls_table *nls = vol->nls_map;
 260         uchar_t *ucs;
 261         wchar_t wc;
 262         int i, o, wc_len;
 263
 264         /* We don't trust outside sources. */
 265         if (ins) {
 266                 ucs = (uchar_t*)kmem_cache_alloc(ntfs_name_cache, SLAB_NOFS);
 267                 if (ucs) {
 268                         for (i = o = 0; i < ins_len; i += wc_len) {
 269                                 wc_len = nls->char2uni(ins + i, ins_len - i,
 270                                                 &wc);
 271                                 if (wc_len >= 0) {
 272                                         if (wc) {
 273                                                 ucs[o++] = cpu_to_le16(wc);
 274                                                 continue;
 275                                         } /* else (!wc) */
 276                                         break;
 277                                 } /* else (wc_len < 0) */
 278                                 goto conversion_err;
 279                         }
 280                         ucs[o] = cpu_to_le16('\0');
 281                         *outs = ucs;
 282                         return o;
 283                 } /* else (!ucs) */
 284                 ntfs_error(vol->sb, "Failed to allocate name from "
 285                                 "ntfs_name_cache!");
 286                 return -ENOMEM;
 287         } /* else (!ins) */
 288         ntfs_error(NULL, "Received NULL pointer.");
 289         return -EINVAL;
 290 conversion_err:
 291         ntfs_error(vol->sb, "Name using character set %s contains characters "
 292                         "that cannot be converted to Unicode.", nls->charset);
 293         kmem_cache_free(ntfs_name_cache, ucs);
 294         return -EILSEQ;
 295 }
 296
 297 /**
 298  * ntfs_ucstonls - convert little endian Unicode string to NLS string
 299  * @vol:        ntfs volume which we are working with
 300  * @ins:        input Unicode string buffer
 301  * @ins_len:    length of input string in Unicode characters
 302  * @outs:       on return contains the (allocated) output NLS string buffer
 303  * @outs_len:   length of output string buffer in bytes
 304  *
 305  * Convert the input little endian, 2-byte Unicode string @ins, of length
 306  * @ins_len into the string format dictated by the loaded NLS.
 307  *
 308  * If @outs is NULL, this function allocates the string and the caller is
 309  * responsible for calling kfree(@outs); when finished with it.
 310  *
 311  * On success the function returns the number of bytes written to the output
 312  * string *@outs (>= 0), not counting the terminating NULL byte. If the output
 313  * string buffer was allocated, *@outs is set to it.
 314  *
 315  * On error, a negative number corresponding to the error code is returned. In
 316  * that case the output string is not allocated. The contents of *@outs are
 317  * then undefined.
 318  *
 319  * This might look a bit odd due to fast path optimization...
 320  */
 321 int ntfs_ucstonls(const ntfs_volume *vol, const uchar_t *ins,
 322                 const int ins_len, unsigned char **outs, int outs_len)
 323 {
 324         struct nls_table *nls = vol->nls_map;
 325         unsigned char *ns;
 326         int i, o, ns_len, wc;
 327
 328         /* We don't trust outside sources. */
 329         if (ins) {
 330                 ns = *outs;
 331                 ns_len = outs_len;
 332                 if (ns && !ns_len) {
 333                         wc = -ENAMETOOLONG;
 334                         goto conversion_err;
 335                 }
 336                 if (!ns) {
 337                         ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
 338                         ns = (unsigned char*)kmalloc(ns_len + 1, GFP_NOFS);
 339                         if (!ns)
 340                                 goto mem_err_out;
 341                 }
 342                 for (i = o = 0; i < ins_len; i++) {
 343 retry:                  wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
 344                                         ns_len - o);
 345                         if (wc > 0) {
 346                                 o += wc;
 347                                 continue;
 348                         } else if (!wc)
 349                                 break;
 350                         else if (wc == -ENAMETOOLONG && ns != *outs) {
 351                                 unsigned char *tc;
 352                                 /* Grow in multiples of 64 bytes. */
 353                                 tc = (unsigned char*)kmalloc((ns_len + 64) &
 354                                                 ~63, GFP_NOFS);
 355                                 if (tc) {
 356                                         memcpy(tc, ns, ns_len);
 357                                         ns_len = ((ns_len + 64) & ~63) - 1;
 358                                         kfree(ns);
 359                                         ns = tc;
 360                                         goto retry;
 361                                 } /* No memory so goto conversion_error; */
 362                         } /* wc < 0, real error. */
 363                         goto conversion_err;
 364                 }
 365                 ns[o] = '\0';
 366                 *outs = ns;
 367                 return o;
 368         } /* else (!ins) */
 369         ntfs_error(vol->sb, "Received NULL pointer.");
 370         return -EINVAL;
 371 conversion_err:
 372         ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
 373                         "converted to character set %s.", nls->charset);
 374         if (ns != *outs)
 375                 kfree(ns);
 376         if (wc != -ENAMETOOLONG)
 377                 wc = -EILSEQ;
 378         return wc;
 379 mem_err_out:
 380         ntfs_error(vol->sb, "Failed to allocate name!");
 381         return -ENOMEM;
 382 }
 383