fs/ntfs/unistr.c

   1 /*
   2  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
   3  *
   4  * Copyright (c) 2001-2006 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 <linux/slab.h>
  23
  24 #include "types.h"
  25 #include "debug.h"
  26 #include "ntfs.h"
  27
  28 /*
  29  * IMPORTANT
  30  * =========
  31  *
  32  * All these routines assume that the Unicode characters are in little endian
  33  * encoding inside the strings!!!
  34  */
  35
  36 /*
  37  * This is used by the name collation functions to quickly determine what
  38  * characters are (in)valid.
  39  */
  40 static const u8 legal_ansi_char_array[0x40] = {
  41         0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  42         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  43
  44         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  45         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  46
  47         0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
  48         0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
  49
  50         0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
  51         0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
  52 };
  53
  54 /**
  55  * ntfs_are_names_equal - compare two Unicode names for equality
  56  * @s1:                 name to compare to @s2
  57  * @s1_len:             length in Unicode characters of @s1
  58  * @s2:                 name to compare to @s1
  59  * @s2_len:             length in Unicode characters of @s2
  60  * @ic:                 ignore case bool
  61  * @upcase:             upcase table (only if @ic == IGNORE_CASE)
  62  * @upcase_size:        length in Unicode characters of @upcase (if present)
  63  *
  64  * Compare the names @s1 and @s2 and return 'true' (1) if the names are
  65  * identical, or 'false' (0) if they are not identical. If @ic is IGNORE_CASE,
  66  * the @upcase table is used to performa a case insensitive comparison.
  67  */
  68 bool ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
  69                 const ntfschar *s2, size_t s2_len, const IGNORE_CASE_BOOL ic,
  70                 const ntfschar *upcase, const u32 upcase_size)
  71 {
  72         if (s1_len != s2_len)
  73                 return false;
  74         if (ic == CASE_SENSITIVE)
  75                 return !ntfs_ucsncmp(s1, s2, s1_len);
  76         return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
  77 }
  78
  79 /**
  80  * ntfs_collate_names - collate two Unicode names
  81  * @name1:      first Unicode name to compare
  82  * @name2:      second Unicode name to compare
  83  * @err_val:    if @name1 contains an invalid character return this value
  84  * @ic:         either CASE_SENSITIVE or IGNORE_CASE
  85  * @upcase:     upcase table (ignored if @ic is CASE_SENSITIVE)
  86  * @upcase_len: upcase table size (ignored if @ic is CASE_SENSITIVE)
  87  *
  88  * ntfs_collate_names collates two Unicode names and returns:
  89  *
  90  *  -1 if the first name collates before the second one,
  91  *   0 if the names match,
  92  *   1 if the second name collates before the first one, or
  93  * @err_val if an invalid character is found in @name1 during the comparison.
  94  *
  95  * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
  96  */
  97 int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
  98                 const ntfschar *name2, const u32 name2_len,
  99                 const int err_val, const IGNORE_CASE_BOOL ic,
 100                 const ntfschar *upcase, const u32 upcase_len)
 101 {
 102         u32 cnt, min_len;
 103         u16 c1, c2;
 104
 105         min_len = name1_len;
 106         if (name1_len > name2_len)
 107                 min_len = name2_len;
 108         for (cnt = 0; cnt < min_len; ++cnt) {
 109                 c1 = le16_to_cpu(*name1++);
 110                 c2 = le16_to_cpu(*name2++);
 111                 if (ic) {
 112                         if (c1 < upcase_len)
 113                                 c1 = le16_to_cpu(upcase[c1]);
 114                         if (c2 < upcase_len)
 115                                 c2 = le16_to_cpu(upcase[c2]);
 116                 }
 117                 if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 118                         return err_val;
 119                 if (c1 < c2)
 120                         return -1;
 121                 if (c1 > c2)
 122                         return 1;
 123         }
 124         if (name1_len < name2_len)
 125                 return -1;
 126         if (name1_len == name2_len)
 127                 return 0;
 128         /* name1_len > name2_len */
 129         c1 = le16_to_cpu(*name1);
 130         if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 131                 return err_val;
 132         return 1;
 133 }
 134
 135 /**
 136  * ntfs_ucsncmp - compare two little endian Unicode strings
 137  * @s1:         first string
 138  * @s2:         second string
 139  * @n:          maximum unicode characters to compare
 140  *
 141  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 142  * The strings in little endian format and appropriate le16_to_cpu()
 143  * conversion is performed on non-little endian machines.
 144  *
 145  * The function returns an integer less than, equal to, or greater than zero
 146  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 147  * to be less than, to match, or be greater than @s2.
 148  */
 149 int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n)
 150 {
 151         u16 c1, c2;
 152         size_t i;
 153
 154         for (i = 0; i < n; ++i) {
 155                 c1 = le16_to_cpu(s1[i]);
 156                 c2 = le16_to_cpu(s2[i]);
 157                 if (c1 < c2)
 158                         return -1;
 159                 if (c1 > c2)
 160                         return 1;
 161                 if (!c1)
 162                         break;
 163         }
 164         return 0;
 165 }
 166
 167 /**
 168  * ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
 169  * @s1:                 first string
 170  * @s2:                 second string
 171  * @n:                  maximum unicode characters to compare
 172  * @upcase:             upcase table
 173  * @upcase_size:        upcase table size in Unicode characters
 174  *
 175  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 176  * ignoring case. The strings in little endian format and appropriate
 177  * le16_to_cpu() conversion is performed on non-little endian machines.
 178  *
 179  * Each character is uppercased using the @upcase table before the comparison.
 180  *
 181  * The function returns an integer less than, equal to, or greater than zero
 182  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 183  * to be less than, to match, or be greater than @s2.
 184  */
 185 int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
 186                 const ntfschar *upcase, const u32 upcase_size)
 187 {
 188         size_t i;
 189         u16 c1, c2;
 190
 191         for (i = 0; i < n; ++i) {
 192                 if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
 193                         c1 = le16_to_cpu(upcase[c1]);
 194                 if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
 195                         c2 = le16_to_cpu(upcase[c2]);
 196                 if (c1 < c2)
 197                         return -1;
 198                 if (c1 > c2)
 199                         return 1;
 200                 if (!c1)
 201                         break;
 202         }
 203         return 0;
 204 }
 205
 206 void ntfs_upcase_name(ntfschar *name, u32 name_len, const ntfschar *upcase,
 207                 const u32 upcase_len)
 208 {
 209         u32 i;
 210         u16 u;
 211
 212         for (i = 0; i < name_len; i++)
 213                 if ((u = le16_to_cpu(name[i])) < upcase_len)
 214                         name[i] = upcase[u];
 215 }
 216
 217 void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
 218                 const ntfschar *upcase, const u32 upcase_len)
 219 {
 220         ntfs_upcase_name((ntfschar*)&file_name_attr->file_name,
 221                         file_name_attr->file_name_length, upcase, upcase_len);
 222 }
 223
 224 int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
 225                 FILE_NAME_ATTR *file_name_attr2,
 226                 const int err_val, const IGNORE_CASE_BOOL ic,
 227                 const ntfschar *upcase, const u32 upcase_len)
 228 {
 229         return ntfs_collate_names((ntfschar*)&file_name_attr1->file_name,
 230                         file_name_attr1->file_name_length,
 231                         (ntfschar*)&file_name_attr2->file_name,
 232                         file_name_attr2->file_name_length,
 233                         err_val, ic, upcase, upcase_len);
 234 }
 235
 236 /**
 237  * ntfs_nlstoucs - convert NLS string to little endian Unicode string
 238  * @vol:        ntfs volume which we are working with
 239  * @ins:        input NLS string buffer
 240  * @ins_len:    length of input string in bytes
 241  * @outs:       on return contains the allocated output Unicode string buffer
 242  *
 243  * Convert the input string @ins, which is in whatever format the loaded NLS
 244  * map dictates, into a little endian, 2-byte Unicode string.
 245  *
 246  * This function allocates the string and the caller is responsible for
 247  * calling kmem_cache_free(ntfs_name_cache, *@outs); when finished with it.
 248  *
 249  * On success the function returns the number of Unicode characters written to
 250  * the output string *@outs (>= 0), not counting the terminating Unicode NULL
 251  * character. *@outs is set to the allocated output string buffer.
 252  *
 253  * On error, a negative number corresponding to the error code is returned. In
 254  * that case the output string is not allocated. Both *@outs and *@outs_len
 255  * are then undefined.
 256  *
 257  * This might look a bit odd due to fast path optimization...
 258  */
 259 int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
 260                 const int ins_len, ntfschar **outs)
 261 {
 262         struct nls_table *nls = vol->nls_map;
 263         ntfschar *ucs;
 264         wchar_t wc;
 265         int i, o, wc_len;
 266
 267         /* We do not trust outside sources. */
 268         if (likely(ins)) {
 269                 ucs = kmem_cache_alloc(ntfs_name_cache, GFP_NOFS);
 270                 if (likely(ucs)) {
 271                         for (i = o = 0; i < ins_len; i += wc_len) {
 272                                 wc_len = nls->char2uni(ins + i, ins_len - i,
 273                                                 &wc);
 274                                 if (likely(wc_len >= 0 &&
 275                                                 o < NTFS_MAX_NAME_LEN)) {
 276                                         if (likely(wc)) {
 277                                                 ucs[o++] = cpu_to_le16(wc);
 278                                                 continue;
 279                                         } /* else if (!wc) */
 280                                         break;
 281                                 } /* else if (wc_len < 0 ||
 282                                                 o >= NTFS_MAX_NAME_LEN) */
 283                                 goto name_err;
 284                         }
 285                         ucs[o] = 0;
 286                         *outs = ucs;
 287                         return o;
 288                 } /* else if (!ucs) */
 289                 ntfs_error(vol->sb, "Failed to allocate buffer for converted "
 290                                 "name from ntfs_name_cache.");
 291                 return -ENOMEM;
 292         } /* else if (!ins) */
 293         ntfs_error(vol->sb, "Received NULL pointer.");
 294         return -EINVAL;
 295 name_err:
 296         kmem_cache_free(ntfs_name_cache, ucs);
 297         if (wc_len < 0) {
 298                 ntfs_error(vol->sb, "Name using character set %s contains "
 299                                 "characters that cannot be converted to "
 300                                 "Unicode.", nls->charset);
 301                 i = -EILSEQ;
 302         } else /* if (o >= NTFS_MAX_NAME_LEN) */ {
 303                 ntfs_error(vol->sb, "Name is too long (maximum length for a "
 304                                 "name on NTFS is %d Unicode characters.",
 305                                 NTFS_MAX_NAME_LEN);
 306                 i = -ENAMETOOLONG;
 307         }
 308         return i;
 309 }
 310
 311 /**
 312  * ntfs_ucstonls - convert little endian Unicode string to NLS string
 313  * @vol:        ntfs volume which we are working with
 314  * @ins:        input Unicode string buffer
 315  * @ins_len:    length of input string in Unicode characters
 316  * @outs:       on return contains the (allocated) output NLS string buffer
 317  * @outs_len:   length of output string buffer in bytes
 318  *
 319  * Convert the input little endian, 2-byte Unicode string @ins, of length
 320  * @ins_len into the string format dictated by the loaded NLS.
 321  *
 322  * If *@outs is NULL, this function allocates the string and the caller is
 323  * responsible for calling kfree(*@outs); when finished with it. In this case
 324  * @outs_len is ignored and can be 0.
 325  *
 326  * On success the function returns the number of bytes written to the output
 327  * string *@outs (>= 0), not counting the terminating NULL byte. If the output
 328  * string buffer was allocated, *@outs is set to it.
 329  *
 330  * On error, a negative number corresponding to the error code is returned. In
 331  * that case the output string is not allocated. The contents of *@outs are
 332  * then undefined.
 333  *
 334  * This might look a bit odd due to fast path optimization...
 335  */
 336 int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
 337                 const int ins_len, unsigned char **outs, int outs_len)
 338 {
 339         struct nls_table *nls = vol->nls_map;
 340         unsigned char *ns;
 341         int i, o, ns_len, wc;
 342
 343         /* We don't trust outside sources. */
 344         if (ins) {
 345                 ns = *outs;
 346                 ns_len = outs_len;
 347                 if (ns && !ns_len) {
 348                         wc = -ENAMETOOLONG;
 349                         goto conversion_err;
 350                 }
 351                 if (!ns) {
 352                         ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
 353                         ns = kmalloc(ns_len + 1, GFP_NOFS);
 354                         if (!ns)
 355                                 goto mem_err_out;
 356                 }
 357                 for (i = o = 0; i < ins_len; i++) {
 358 retry:                  wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
 359                                         ns_len - o);
 360                         if (wc > 0) {
 361                                 o += wc;
 362                                 continue;
 363                         } else if (!wc)
 364                                 break;
 365                         else if (wc == -ENAMETOOLONG && ns != *outs) {
 366                                 unsigned char *tc;
 367                                 /* Grow in multiples of 64 bytes. */
 368                                 tc = kmalloc((ns_len + 64) &
 369                                                 ~63, GFP_NOFS);
 370                                 if (tc) {
 371                                         memcpy(tc, ns, ns_len);
 372                                         ns_len = ((ns_len + 64) & ~63) - 1;
 373                                         kfree(ns);
 374                                         ns = tc;
 375                                         goto retry;
 376                                 } /* No memory so goto conversion_error; */
 377                         } /* wc < 0, real error. */
 378                         goto conversion_err;
 379                 }
 380                 ns[o] = 0;
 381                 *outs = ns;
 382                 return o;
 383         } /* else (!ins) */
 384         ntfs_error(vol->sb, "Received NULL pointer.");
 385         return -EINVAL;
 386 conversion_err:
 387         ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
 388                         "converted to character set %s.  You might want to "
 389                         "try to use the mount option nls=utf8.", nls->charset);
 390         if (ns != *outs)
 391                 kfree(ns);
 392         if (wc != -ENAMETOOLONG)
 393                 wc = -EILSEQ;
 394         return wc;
 395 mem_err_out:
 396         ntfs_error(vol->sb, "Failed to allocate name!");
 397         return -ENOMEM;
 398 }