fs/ntfs/unistr.c

   1 /*
   2  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
   3  *
   4  * Copyright (c) 2001-2005 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 "types.h"
  23 #include "debug.h"
  24 #include "ntfs.h"
  25
  26 /*
  27  * IMPORTANT
  28  * =========
  29  *
  30  * All these routines assume that the Unicode characters are in little endian
  31  * encoding inside the strings!!!
  32  */
  33
  34 /*
  35  * This is used by the name collation functions to quickly determine what
  36  * characters are (in)valid.
  37  */
  38 static const u8 legal_ansi_char_array[0x40] = {
  39         0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  40         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  41
  42         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  43         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  44
  45         0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
  46         0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
  47
  48         0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
  49         0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
  50 };
  51
  52 /**
  53  * ntfs_are_names_equal - compare two Unicode names for equality
  54  * @s1:                 name to compare to @s2
  55  * @s1_len:             length in Unicode characters of @s1
  56  * @s2:                 name to compare to @s1
  57  * @s2_len:             length in Unicode characters of @s2
  58  * @ic:                 ignore case bool
  59  * @upcase:             upcase table (only if @ic == IGNORE_CASE)
  60  * @upcase_size:        length in Unicode characters of @upcase (if present)
  61  *
  62  * Compare the names @s1 and @s2 and return TRUE (1) if the names are
  63  * identical, or FALSE (0) if they are not identical. If @ic is IGNORE_CASE,
  64  * the @upcase table is used to performa a case insensitive comparison.
  65  */
  66 BOOL ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
  67                 const ntfschar *s2, size_t s2_len, const IGNORE_CASE_BOOL ic,
  68                 const ntfschar *upcase, const u32 upcase_size)
  69 {
  70         if (s1_len != s2_len)
  71                 return FALSE;
  72         if (ic == CASE_SENSITIVE)
  73                 return !ntfs_ucsncmp(s1, s2, s1_len);
  74         return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
  75 }
  76
  77 /**
  78  * ntfs_collate_names - collate two Unicode names
  79  * @name1:      first Unicode name to compare
  80  * @name2:      second Unicode name to compare
  81  * @err_val:    if @name1 contains an invalid character return this value
  82  * @ic:         either CASE_SENSITIVE or IGNORE_CASE
  83  * @upcase:     upcase table (ignored if @ic is CASE_SENSITIVE)
  84  * @upcase_len: upcase table size (ignored if @ic is CASE_SENSITIVE)
  85  *
  86  * ntfs_collate_names collates two Unicode names and returns:
  87  *
  88  *  -1 if the first name collates before the second one,
  89  *   0 if the names match,
  90  *   1 if the second name collates before the first one, or
  91  * @err_val if an invalid character is found in @name1 during the comparison.
  92  *
  93  * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
  94  */
  95 int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
  96                 const ntfschar *name2, const u32 name2_len,
  97                 const int err_val, const IGNORE_CASE_BOOL ic,
  98                 const ntfschar *upcase, const u32 upcase_len)
  99 {
 100         u32 cnt, min_len;
 101         u16 c1, c2;
 102
 103         min_len = name1_len;
 104         if (name1_len > name2_len)
 105                 min_len = name2_len;
 106         for (cnt = 0; cnt < min_len; ++cnt) {
 107                 c1 = le16_to_cpu(*name1++);
 108                 c2 = le16_to_cpu(*name2++);
 109                 if (ic) {
 110                         if (c1 < upcase_len)
 111                                 c1 = le16_to_cpu(upcase[c1]);
 112                         if (c2 < upcase_len)
 113                                 c2 = le16_to_cpu(upcase[c2]);
 114                 }
 115                 if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 116                         return err_val;
 117                 if (c1 < c2)
 118                         return -1;
 119                 if (c1 > c2)
 120                         return 1;
 121         }
 122         if (name1_len < name2_len)
 123                 return -1;
 124         if (name1_len == name2_len)
 125                 return 0;
 126         /* name1_len > name2_len */
 127         c1 = le16_to_cpu(*name1);
 128         if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 129                 return err_val;
 130         return 1;
 131 }
 132
 133 /**
 134  * ntfs_ucsncmp - compare two little endian Unicode strings
 135  * @s1:         first string
 136  * @s2:         second string
 137  * @n:          maximum unicode characters to compare
 138  *
 139  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 140  * The strings in little endian format and appropriate le16_to_cpu()
 141  * conversion is performed on non-little endian machines.
 142  *
 143  * The function returns an integer less than, equal to, or greater than zero
 144  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 145  * to be less than, to match, or be greater than @s2.
 146  */
 147 int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n)
 148 {
 149         u16 c1, c2;
 150         size_t i;
 151
 152         for (i = 0; i < n; ++i) {
 153                 c1 = le16_to_cpu(s1[i]);
 154                 c2 = le16_to_cpu(s2[i]);
 155                 if (c1 < c2)
 156                         return -1;
 157                 if (c1 > c2)
 158                         return 1;
 159                 if (!c1)
 160                         break;
 161         }
 162         return 0;
 163 }
 164
 165 /**
 166  * ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
 167  * @s1:                 first string
 168  * @s2:                 second string
 169  * @n:                  maximum unicode characters to compare
 170  * @upcase:             upcase table
 171  * @upcase_size:        upcase table size in Unicode characters
 172  *
 173  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 174  * ignoring case. The strings in little endian format and appropriate
 175  * le16_to_cpu() conversion is performed on non-little endian machines.
 176  *
 177  * Each character is uppercased using the @upcase table before the comparison.
 178  *
 179  * The function returns an integer less than, equal to, or greater than zero
 180  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 181  * to be less than, to match, or be greater than @s2.
 182  */
 183 int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
 184                 const ntfschar *upcase, const u32 upcase_size)
 185 {
 186         size_t i;
 187         u16 c1, c2;
 188
 189         for (i = 0; i < n; ++i) {
 190                 if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
 191                         c1 = le16_to_cpu(upcase[c1]);
 192                 if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
 193                         c2 = le16_to_cpu(upcase[c2]);
 194                 if (c1 < c2)
 195                         return -1;
 196                 if (c1 > c2)
 197                         return 1;
 198                 if (!c1)
 199                         break;
 200         }
 201         return 0;
 202 }
 203
 204 void ntfs_upcase_name(ntfschar *name, u32 name_len, const ntfschar *upcase,
 205                 const u32 upcase_len)
 206 {
 207         u32 i;
 208         u16 u;
 209
 210         for (i = 0; i < name_len; i++)
 211                 if ((u = le16_to_cpu(name[i])) < upcase_len)
 212                         name[i] = upcase[u];
 213 }
 214
 215 void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
 216                 const ntfschar *upcase, const u32 upcase_len)
 217 {
 218         ntfs_upcase_name((ntfschar*)&file_name_attr->file_name,
 219                         file_name_attr->file_name_length, upcase, upcase_len);
 220 }
 221
 222 int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
 223                 FILE_NAME_ATTR *file_name_attr2,
 224                 const int err_val, const IGNORE_CASE_BOOL ic,
 225                 const ntfschar *upcase, const u32 upcase_len)
 226 {
 227         return ntfs_collate_names((ntfschar*)&file_name_attr1->file_name,
 228                         file_name_attr1->file_name_length,
 229                         (ntfschar*)&file_name_attr2->file_name,
 230                         file_name_attr2->file_name_length,
 231                         err_val, ic, upcase, upcase_len);
 232 }
 233
 234 /**
 235  * ntfs_nlstoucs - convert NLS string to little endian Unicode string
 236  * @vol:        ntfs volume which we are working with
 237  * @ins:        input NLS string buffer
 238  * @ins_len:    length of input string in bytes
 239  * @outs:       on return contains the allocated output Unicode string buffer
 240  *
 241  * Convert the input string @ins, which is in whatever format the loaded NLS
 242  * map dictates, into a little endian, 2-byte Unicode string.
 243  *
 244  * This function allocates the string and the caller is responsible for
 245  * calling kmem_cache_free(ntfs_name_cache, @outs); when finished with it.
 246  *
 247  * On success the function returns the number of Unicode characters written to
 248  * the output string *@outs (>= 0), not counting the terminating Unicode NULL
 249  * character. *@outs is set to the allocated output string buffer.
 250  *
 251  * On error, a negative number corresponding to the error code is returned. In
 252  * that case the output string is not allocated. Both *@outs and *@outs_len
 253  * are then undefined.
 254  *
 255  * This might look a bit odd due to fast path optimization...
 256  */
 257 int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
 258                 const int ins_len, ntfschar **outs)
 259 {
 260         struct nls_table *nls = vol->nls_map;
 261         ntfschar *ucs;
 262         wchar_t wc;
 263         int i, o, wc_len;
 264
 265         /* We don't trust outside sources. */
 266         if (ins) {
 267                 ucs = kmem_cache_alloc(ntfs_name_cache, SLAB_NOFS);
 268                 if (ucs) {
 269                         for (i = o = 0; i < ins_len; i += wc_len) {
 270                                 wc_len = nls->char2uni(ins + i, ins_len - i,
 271                                                 &wc);
 272                                 if (wc_len >= 0) {
 273                                         if (wc) {
 274                                                 ucs[o++] = cpu_to_le16(wc);
 275                                                 continue;
 276                                         } /* else (!wc) */
 277                                         break;
 278                                 } /* else (wc_len < 0) */
 279                                 goto conversion_err;
 280                         }
 281                         ucs[o] = 0;
 282                         *outs = ucs;
 283                         return o;
 284                 } /* else (!ucs) */
 285                 ntfs_error(vol->sb, "Failed to allocate name from "
 286                                 "ntfs_name_cache!");
 287                 return -ENOMEM;
 288         } /* else (!ins) */
 289         ntfs_error(NULL, "Received NULL pointer.");
 290         return -EINVAL;
 291 conversion_err:
 292         ntfs_error(vol->sb, "Name using character set %s contains characters "
 293                         "that cannot be converted to Unicode.", nls->charset);
 294         kmem_cache_free(ntfs_name_cache, ucs);
 295         return -EILSEQ;
 296 }
 297
 298 /**
 299  * ntfs_ucstonls - convert little endian Unicode string to NLS string
 300  * @vol:        ntfs volume which we are working with
 301  * @ins:        input Unicode string buffer
 302  * @ins_len:    length of input string in Unicode characters
 303  * @outs:       on return contains the (allocated) output NLS string buffer
 304  * @outs_len:   length of output string buffer in bytes
 305  *
 306  * Convert the input little endian, 2-byte Unicode string @ins, of length
 307  * @ins_len into the string format dictated by the loaded NLS.
 308  *
 309  * If *@outs is NULL, this function allocates the string and the caller is
 310  * responsible for calling kfree(*@outs); when finished with it. In this case
 311  * @outs_len is ignored and can be 0.
 312  *
 313  * On success the function returns the number of bytes written to the output
 314  * string *@outs (>= 0), not counting the terminating NULL byte. If the output
 315  * string buffer was allocated, *@outs is set to it.
 316  *
 317  * On error, a negative number corresponding to the error code is returned. In
 318  * that case the output string is not allocated. The contents of *@outs are
 319  * then undefined.
 320  *
 321  * This might look a bit odd due to fast path optimization...
 322  */
 323 int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
 324                 const int ins_len, unsigned char **outs, int outs_len)
 325 {
 326         struct nls_table *nls = vol->nls_map;
 327         unsigned char *ns;
 328         int i, o, ns_len, wc;
 329
 330         /* We don't trust outside sources. */
 331         if (ins) {
 332                 ns = *outs;
 333                 ns_len = outs_len;
 334                 if (ns && !ns_len) {
 335                         wc = -ENAMETOOLONG;
 336                         goto conversion_err;
 337                 }
 338                 if (!ns) {
 339                         ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
 340                         ns = (unsigned char*)kmalloc(ns_len + 1, GFP_NOFS);
 341                         if (!ns)
 342                                 goto mem_err_out;
 343                 }
 344                 for (i = o = 0; i < ins_len; i++) {
 345 retry:                  wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
 346                                         ns_len - o);
 347                         if (wc > 0) {
 348                                 o += wc;
 349                                 continue;
 350                         } else if (!wc)
 351                                 break;
 352                         else if (wc == -ENAMETOOLONG && ns != *outs) {
 353                                 unsigned char *tc;
 354                                 /* Grow in multiples of 64 bytes. */
 355                                 tc = (unsigned char*)kmalloc((ns_len + 64) &
 356                                                 ~63, GFP_NOFS);
 357                                 if (tc) {
 358                                         memcpy(tc, ns, ns_len);
 359                                         ns_len = ((ns_len + 64) & ~63) - 1;
 360                                         kfree(ns);
 361                                         ns = tc;
 362                                         goto retry;
 363                                 } /* No memory so goto conversion_error; */
 364                         } /* wc < 0, real error. */
 365                         goto conversion_err;
 366                 }
 367                 ns[o] = 0;
 368                 *outs = ns;
 369                 return o;
 370         } /* else (!ins) */
 371         ntfs_error(vol->sb, "Received NULL pointer.");
 372         return -EINVAL;
 373 conversion_err:
 374         ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
 375                         "converted to character set %s.  You might want to "
 376                         "try to use the mount option nls=utf8.", nls->charset);
 377         if (ns != *outs)
 378                 kfree(ns);
 379         if (wc != -ENAMETOOLONG)
 380                 wc = -EILSEQ;
 381         return wc;
 382 mem_err_out:
 383         ntfs_error(vol->sb, "Failed to allocate name!");
 384         return -ENOMEM;
 385 }