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   1 /*
   2  * encoding.c
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 2013 Eric Biggers
   7  *
   8  * This file is part of wimlib, a library for working with WIM files.
   9  *
  10  * wimlib is free software; you can redistribute it and/or modify it under the
  11  * terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 3 of the License, or (at your option)
  13  * any later version.
  14  *
  15  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  16  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  17  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  22  */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include "config.h"
  26 #endif
  27
  28 #include "wimlib.h"
  29 #include "wimlib/encoding.h"
  30 #include "wimlib/endianness.h"
  31 #include "wimlib/error.h"
  32 #include "wimlib/list.h"
  33 #include "wimlib/util.h"
  34
  35 #include <errno.h>
  36 #include <iconv.h>
  37 #include <pthread.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 bool wimlib_mbs_is_utf8 = !TCHAR_IS_UTF16LE;
  42
  43 /* List of iconv_t conversion descriptors for a specific character conversion.
  44  * The idea is that it is not thread-safe to have just one conversion
  45  * descriptor, but it also is inefficient to open a new conversion descriptor to
  46  * convert every string.  Both these problems can be solved by maintaining a
  47  * list of conversion descriptors; then, a thread can use an existing conversion
  48  * descriptor if available. */
  49 struct iconv_list_head {
  50         const char *from_encoding;
  51         const char *to_encoding;
  52         struct list_head list;
  53         pthread_mutex_t mutex;
  54 };
  55
  56 struct iconv_node {
  57         iconv_t cd;
  58         struct list_head list;
  59         struct iconv_list_head *head;
  60 };
  61
  62 #define ICONV_LIST(name, from, to)                      \
  63 struct iconv_list_head name = {                         \
  64         .from_encoding = from,                          \
  65         .to_encoding = to,                              \
  66         .list = LIST_HEAD_INIT(name.list),              \
  67         .mutex = PTHREAD_MUTEX_INITIALIZER,             \
  68 }
  69
  70 static iconv_t *
  71 get_iconv(struct iconv_list_head *head)
  72 {
  73         iconv_t cd;
  74         iconv_t *cd_p;
  75         struct iconv_node *i;
  76
  77         pthread_mutex_lock(&head->mutex);
  78         if (list_empty(&head->list)) {
  79                 cd = iconv_open(head->to_encoding, head->from_encoding);
  80                 if (cd == (iconv_t)-1) {
  81                         ERROR_WITH_ERRNO("Failed to open iconv from %s to %s",
  82                                          head->from_encoding, head->to_encoding);
  83                         cd_p = NULL;
  84                 } else {
  85                         i = MALLOC(sizeof(struct iconv_node));
  86                         if (i) {
  87                                 i->head = head;
  88                                 i->cd = cd;
  89                                 cd_p = &i->cd;
  90                         } else {
  91                                 iconv_close(cd);
  92                                 cd_p = NULL;
  93                         }
  94                 }
  95         } else {
  96                 i = container_of(head->list.next, struct iconv_node, list);
  97                 list_del(head->list.next);
  98                 cd_p = &i->cd;
  99         }
 100         pthread_mutex_unlock(&head->mutex);
 101         return cd_p;
 102 }
 103
 104 static void
 105 put_iconv(iconv_t *cd)
 106 {
 107         int errno_save = errno;
 108         struct iconv_node *i = container_of(cd, struct iconv_node, cd);
 109         struct iconv_list_head *head = i->head;
 110
 111         pthread_mutex_lock(&head->mutex);
 112         list_add(&i->list, &head->list);
 113         pthread_mutex_unlock(&head->mutex);
 114         errno = errno_save;
 115 }
 116
 117 /* Prevent printing an error message if a character conversion error occurs
 118  * while printing an error message.  (This variable is not per-thread but it
 119  * doesn't matter too much since it's just the error messages.) */
 120 static bool error_message_being_printed = false;
 121
 122 #define DEFINE_CHAR_CONVERSION_FUNCTIONS(varname1, longname1, chartype1,\
 123                                          varname2, longname2, chartype2,\
 124                                          earlyreturn_on_utf8_locale,    \
 125                                          earlyreturn_expr,              \
 126                                          worst_case_len_expr,           \
 127                                          err_return,                    \
 128                                          err_msg,                       \
 129                                          modifier)                      \
 130 static ICONV_LIST(iconv_##varname1##_to_##varname2,                     \
 131                   longname1, longname2);                                \
 132                                                                         \
 133 modifier int                                                            \
 134 varname1##_to_##varname2##_nbytes(const chartype1 *in, size_t in_nbytes,\
 135                                   size_t *out_nbytes_ret)               \
 136 {                                                                       \
 137         iconv_t *cd = get_iconv(&iconv_##varname1##_to_##varname2);     \
 138         if (cd == NULL)                                                 \
 139                 return WIMLIB_ERR_ICONV_NOT_AVAILABLE;                  \
 140                                                                         \
 141         /* Worst case length */                                         \
 142         chartype2 buf[worst_case_len_expr];                             \
 143         char *inbuf = (char*)in;                                        \
 144         size_t inbytesleft = in_nbytes;                                 \
 145         char *outbuf = (char*)buf;                                      \
 146         size_t outbytesleft = sizeof(buf);                              \
 147         size_t len;                                                     \
 148         int ret;                                                        \
 149                                                                         \
 150         len = iconv(*cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft); \
 151         if (len == (size_t)-1) {                                        \
 152                 if (!error_message_being_printed) {                     \
 153                         error_message_being_printed = true;             \
 154                         err_msg;                                        \
 155                         error_message_being_printed = false;            \
 156                 }                                                       \
 157                 ret = err_return;                                       \
 158         } else {                                                        \
 159                 *out_nbytes_ret = sizeof(buf) - outbytesleft;           \
 160                 ret = 0;                                                \
 161         }                                                               \
 162         put_iconv(cd);                                                  \
 163         return ret;                                                     \
 164 }                                                                       \
 165                                                                         \
 166 modifier int                                                            \
 167 varname1##_to_##varname2##_buf(const chartype1 *in, size_t in_nbytes,   \
 168                                chartype2 *out)                          \
 169 {                                                                       \
 170         iconv_t *cd = get_iconv(&iconv_##varname1##_to_##varname2);     \
 171         if (cd == NULL)                                                 \
 172                 return WIMLIB_ERR_ICONV_NOT_AVAILABLE;                  \
 173                                                                         \
 174         char *inbuf = (char*)in;                                        \
 175         size_t inbytesleft = in_nbytes;                                 \
 176         char *outbuf = (char*)out;                                      \
 177         const size_t LARGE_NUMBER = 1000000000;                         \
 178         size_t outbytesleft = LARGE_NUMBER;                             \
 179         size_t len;                                                     \
 180         int ret;                                                        \
 181                                                                         \
 182         len = iconv(*cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft); \
 183         if (len == (size_t)-1) {                                        \
 184                 if (!error_message_being_printed) {                     \
 185                         error_message_being_printed = true;             \
 186                         err_msg;                                        \
 187                         error_message_being_printed = false;            \
 188                 }                                                       \
 189                 ret = err_return;                                       \
 190         } else {                                                        \
 191                 out[(LARGE_NUMBER-outbytesleft)/sizeof(chartype2)] = 0; \
 192                 ret = 0;                                                \
 193         }                                                               \
 194         put_iconv(cd);                                                  \
 195         return ret;                                                     \
 196 }                                                                       \
 197                                                                         \
 198 modifier int                                                            \
 199 varname1##_to_##varname2(const chartype1 *in, size_t in_nbytes,         \
 200                          chartype2 **out_ret,                           \
 201                          size_t *out_nbytes_ret)                        \
 202 {                                                                       \
 203         int ret;                                                        \
 204         chartype2 *out;                                                 \
 205         size_t out_nbytes;                                              \
 206                                                                         \
 207         if (earlyreturn_on_utf8_locale && wimlib_mbs_is_utf8) {         \
 208                 earlyreturn_expr;                                       \
 209                 /* Out same as in */                                    \
 210                 out = MALLOC(in_nbytes + sizeof(chartype2));            \
 211                 if (!out)                                               \
 212                         return WIMLIB_ERR_NOMEM;                        \
 213                 memcpy(out, in, in_nbytes);                             \
 214                 out[in_nbytes / sizeof(chartype2)] = 0;                 \
 215                 *out_ret = out;                                         \
 216                 *out_nbytes_ret = in_nbytes;                            \
 217                 return 0;                                               \
 218         }                                                               \
 219                                                                         \
 220         ret = varname1##_to_##varname2##_nbytes(in, in_nbytes,          \
 221                                                 &out_nbytes);           \
 222         if (ret)                                                        \
 223                 return ret;                                             \
 224                                                                         \
 225         out = MALLOC(out_nbytes + sizeof(chartype2));                   \
 226         if (!out)                                                       \
 227                 return WIMLIB_ERR_NOMEM;                                \
 228                                                                         \
 229         ret = varname1##_to_##varname2##_buf(in, in_nbytes, out);       \
 230         if (ret) {                                                      \
 231                 FREE(out);                                              \
 232         } else {                                                        \
 233                 *out_ret = out;                                         \
 234                 *out_nbytes_ret = out_nbytes;                           \
 235         }                                                               \
 236         return ret;                                                     \
 237 }
 238
 239 #if !TCHAR_IS_UTF16LE
 240
 241 /* UNIX */
 242
 243 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", tchar,
 244                                  utf16le, "UTF-16LE", utf16lechar,
 245                                  false,
 246                                  ,
 247                                  in_nbytes * 2,
 248                                  WIMLIB_ERR_INVALID_UTF8_STRING,
 249                                  ERROR_WITH_ERRNO("Failed to convert UTF-8 string "
 250                                                   "to UTF-16LE string!"),
 251                                  static)
 252
 253 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf16le, "UTF-16LE", utf16lechar,
 254                                  utf8, "UTF-8", tchar,
 255                                  false,
 256                                  ,
 257                                  in_nbytes * 2,
 258                                  WIMLIB_ERR_INVALID_UTF16_STRING,
 259                                  ERROR_WITH_ERRNO("Failed to convert UTF-16LE string "
 260                                                   "to UTF-8 string!"),
 261                                  static)
 262
 263 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "", tchar,
 264                                  utf16le, "UTF-16LE", utf16lechar,
 265                                  true,
 266                                  return utf8_to_utf16le(in, in_nbytes, out_ret, out_nbytes_ret),
 267                                  in_nbytes * 2,
 268                                  WIMLIB_ERR_INVALID_MULTIBYTE_STRING,
 269                                  ERROR_WITH_ERRNO("Failed to convert multibyte "
 270                                                   "string \"%"TS"\" to UTF-16LE string!", in);
 271                                  ERROR("If the data you provided was UTF-8, please make sure "
 272                                        "the character encoding\n"
 273                                        "        of your current locale is UTF-8."),
 274                                  )
 275
 276 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf16le, "UTF-16LE", utf16lechar,
 277                                  tstr, "", tchar,
 278                                  true,
 279                                  return utf16le_to_utf8(in, in_nbytes, out_ret, out_nbytes_ret),
 280                                  in_nbytes * 2,
 281                                  WIMLIB_ERR_UNICODE_STRING_NOT_REPRESENTABLE,
 282                                  ERROR("Failed to convert UTF-16LE string to "
 283                                        "multibyte string!");
 284                                  ERROR("This may be because the UTF-16LE string "
 285                                        "could not be represented\n"
 286                                        "        in your locale's character encoding."),
 287                                  )
 288 #endif
 289
 290 /* tchar to UTF-8 and back */
 291 #if TCHAR_IS_UTF16LE
 292
 293 /* Windows */
 294 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "UTF-16LE", tchar,
 295                                  utf8, "UTF-8", char,
 296                                  false,
 297                                  ,
 298                                  in_nbytes * 2,
 299                                  WIMLIB_ERR_INVALID_UTF16_STRING,
 300                                  ERROR_WITH_ERRNO("Failed to convert UTF-16LE "
 301                                                   "string \"%"TS"\" to UTF-8 string!", in),
 302                                  )
 303
 304 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", char,
 305                                  tstr, "UTF-16LE", tchar,
 306                                  false,
 307                                  ,
 308                                  in_nbytes * 2,
 309                                  WIMLIB_ERR_INVALID_UTF8_STRING,
 310                                  ERROR_WITH_ERRNO("Failed to convert UTF-8 string "
 311                                                   "to UTF-16LE string!"),
 312                                  )
 313 #else
 314
 315 /* UNIX */
 316
 317 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "", tchar,
 318                                  utf8, "UTF-8", char,
 319                                  true,
 320                                  ,
 321                                  in_nbytes * 4,
 322                                  WIMLIB_ERR_INVALID_MULTIBYTE_STRING,
 323                                  ERROR_WITH_ERRNO("Failed to convert multibyte "
 324                                                   "string \"%"TS"\" to UTF-8 string!", in);
 325                                  ERROR("If the data you provided was UTF-8, please make sure "
 326                                        "the character\n"
 327                                        "        encoding of your current locale is UTF-8."),
 328                                  )
 329
 330 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", char,
 331                                  tstr, "", tchar,
 332                                  true,
 333                                  ,
 334                                  in_nbytes * 4,
 335                                  WIMLIB_ERR_UNICODE_STRING_NOT_REPRESENTABLE,
 336                                  ERROR("Failed to convert UTF-8 string to "
 337                                        "multibyte string!");
 338                                  ERROR("This may be because the UTF-8 data "
 339                                        "could not be represented\n"
 340                                        "        in your locale's character encoding."),
 341                                  )
 342 #endif
 343
 344 int
 345 tstr_to_utf8_simple(const tchar *tstr, char **out)
 346 {
 347         size_t out_nbytes;
 348         return tstr_to_utf8(tstr, tstrlen(tstr) * sizeof(tchar),
 349                             out, &out_nbytes);
 350 }
 351
 352 int
 353 utf8_to_tstr_simple(const char *utf8str, tchar **out)
 354 {
 355         size_t out_nbytes;
 356         return utf8_to_tstr(utf8str, strlen(utf8str), out, &out_nbytes);
 357 }
 358
 359 static void
 360 iconv_cleanup(struct iconv_list_head *head)
 361 {
 362         pthread_mutex_destroy(&head->mutex);
 363         while (!list_empty(&head->list)) {
 364                 struct iconv_node *i;
 365
 366                 i = container_of(head->list.next, struct iconv_node, list);
 367                 list_del(&i->list);
 368                 iconv_close(i->cd);
 369                 FREE(i);
 370         }
 371 }
 372
 373 void
 374 iconv_global_cleanup(void)
 375 {
 376         iconv_cleanup(&iconv_utf8_to_tstr);
 377         iconv_cleanup(&iconv_tstr_to_utf8);
 378 #if !TCHAR_IS_UTF16LE
 379         iconv_cleanup(&iconv_utf16le_to_tstr);
 380         iconv_cleanup(&iconv_tstr_to_utf16le);
 381         iconv_cleanup(&iconv_utf16le_to_utf8);
 382         iconv_cleanup(&iconv_utf8_to_utf16le);
 383 #endif
 384 }
 385
 386 /* Upper case table --- Borrowed from NTFS-3g
 387  *
 388  * Copyright (c) 2000-2004 Anton Altaparmakov
 389  * Copyright (c) 2002-2009 Szabolcs Szakacsits
 390  * Copyright (c) 2008-2011 Jean-Pierre Andre
 391  * Copyright (c) 2008      Bernhard Kaindl
 392  *
 393  * License is GPLv2 or later.
 394  */
 395
 396 /**
 397  * ntfs_upcase_table_build - build the default upcase table for NTFS
 398  * @uc:         destination buffer where to store the built table
 399  * @uc_len:     size of destination buffer in bytes
 400  *
 401  * ntfs_upcase_table_build() builds the default upcase table for NTFS and
 402  * stores it in the caller supplied buffer @uc of size @uc_len.
 403  *
 404  * Note, @uc_len must be at least 128kiB in size or bad things will happen!
 405  */
 406 static void
 407 ntfs_upcase_table_build(utf16lechar *uc, u32 uc_len)
 408 {
 409         /*
 410          *      This is the table as defined by Vista
 411          */
 412         /*
 413          * "Start" is inclusive and "End" is exclusive, every value has the
 414          * value of "Add" added to it.
 415          */
 416         static int uc_run_table[][3] = { /* Start, End, Add */
 417         {0x0061, 0x007b,   -32}, {0x00e0, 0x00f7,  -32}, {0x00f8, 0x00ff, -32},
 418         {0x0256, 0x0258,  -205}, {0x028a, 0x028c, -217}, {0x037b, 0x037e, 130},
 419         {0x03ac, 0x03ad,   -38}, {0x03ad, 0x03b0,  -37}, {0x03b1, 0x03c2, -32},
 420         {0x03c2, 0x03c3,   -31}, {0x03c3, 0x03cc,  -32}, {0x03cc, 0x03cd, -64},
 421         {0x03cd, 0x03cf,   -63}, {0x0430, 0x0450,  -32}, {0x0450, 0x0460, -80},
 422         {0x0561, 0x0587,   -48}, {0x1f00, 0x1f08,    8}, {0x1f10, 0x1f16,   8},
 423         {0x1f20, 0x1f28,     8}, {0x1f30, 0x1f38,    8}, {0x1f40, 0x1f46,   8},
 424         {0x1f51, 0x1f52,     8}, {0x1f53, 0x1f54,    8}, {0x1f55, 0x1f56,   8},
 425         {0x1f57, 0x1f58,     8}, {0x1f60, 0x1f68,    8}, {0x1f70, 0x1f72,  74},
 426         {0x1f72, 0x1f76,    86}, {0x1f76, 0x1f78,  100}, {0x1f78, 0x1f7a, 128},
 427         {0x1f7a, 0x1f7c,   112}, {0x1f7c, 0x1f7e,  126}, {0x1f80, 0x1f88,   8},
 428         {0x1f90, 0x1f98,     8}, {0x1fa0, 0x1fa8,    8}, {0x1fb0, 0x1fb2,   8},
 429         {0x1fb3, 0x1fb4,     9}, {0x1fcc, 0x1fcd,   -9}, {0x1fd0, 0x1fd2,   8},
 430         {0x1fe0, 0x1fe2,     8}, {0x1fe5, 0x1fe6,    7}, {0x1ffc, 0x1ffd,  -9},
 431         {0x2170, 0x2180,   -16}, {0x24d0, 0x24ea,  -26}, {0x2c30, 0x2c5f, -48},
 432         {0x2d00, 0x2d26, -7264}, {0xff41, 0xff5b,  -32}, {0}
 433         };
 434         /*
 435          * "Start" is exclusive and "End" is inclusive, every second value is
 436          * decremented by one.
 437          */
 438         static int uc_dup_table[][2] = { /* Start, End */
 439         {0x0100, 0x012f}, {0x0132, 0x0137}, {0x0139, 0x0149}, {0x014a, 0x0178},
 440         {0x0179, 0x017e}, {0x01a0, 0x01a6}, {0x01b3, 0x01b7}, {0x01cd, 0x01dd},
 441         {0x01de, 0x01ef}, {0x01f4, 0x01f5}, {0x01f8, 0x01f9}, {0x01fa, 0x0220},
 442         {0x0222, 0x0234}, {0x023b, 0x023c}, {0x0241, 0x0242}, {0x0246, 0x024f},
 443         {0x03d8, 0x03ef}, {0x03f7, 0x03f8}, {0x03fa, 0x03fb}, {0x0460, 0x0481},
 444         {0x048a, 0x04bf}, {0x04c1, 0x04c4}, {0x04c5, 0x04c8}, {0x04c9, 0x04ce},
 445         {0x04ec, 0x04ed}, {0x04d0, 0x04eb}, {0x04ee, 0x04f5}, {0x04f6, 0x0513},
 446         {0x1e00, 0x1e95}, {0x1ea0, 0x1ef9}, {0x2183, 0x2184}, {0x2c60, 0x2c61},
 447         {0x2c67, 0x2c6c}, {0x2c75, 0x2c76}, {0x2c80, 0x2ce3}, {0}
 448         };
 449         /*
 450          * Set the Unicode character at offset "Offset" to "Value".  Note,
 451          * "Value" is host endian.
 452          */
 453         static int uc_byte_table[][2] = { /* Offset, Value */
 454         {0x00ff, 0x0178}, {0x0180, 0x0243}, {0x0183, 0x0182}, {0x0185, 0x0184},
 455         {0x0188, 0x0187}, {0x018c, 0x018b}, {0x0192, 0x0191}, {0x0195, 0x01f6},
 456         {0x0199, 0x0198}, {0x019a, 0x023d}, {0x019e, 0x0220}, {0x01a8, 0x01a7},
 457         {0x01ad, 0x01ac}, {0x01b0, 0x01af}, {0x01b9, 0x01b8}, {0x01bd, 0x01bc},
 458         {0x01bf, 0x01f7}, {0x01c6, 0x01c4}, {0x01c9, 0x01c7}, {0x01cc, 0x01ca},
 459         {0x01dd, 0x018e}, {0x01f3, 0x01f1}, {0x023a, 0x2c65}, {0x023e, 0x2c66},
 460         {0x0253, 0x0181}, {0x0254, 0x0186}, {0x0259, 0x018f}, {0x025b, 0x0190},
 461         {0x0260, 0x0193}, {0x0263, 0x0194}, {0x0268, 0x0197}, {0x0269, 0x0196},
 462         {0x026b, 0x2c62}, {0x026f, 0x019c}, {0x0272, 0x019d}, {0x0275, 0x019f},
 463         {0x027d, 0x2c64}, {0x0280, 0x01a6}, {0x0283, 0x01a9}, {0x0288, 0x01ae},
 464         {0x0289, 0x0244}, {0x028c, 0x0245}, {0x0292, 0x01b7}, {0x03f2, 0x03f9},
 465         {0x04cf, 0x04c0}, {0x1d7d, 0x2c63}, {0x214e, 0x2132}, {0}
 466         };
 467         int i, r;
 468         int k, off;
 469
 470         memset((char*)uc, 0, uc_len);
 471         uc_len >>= 1;
 472         if (uc_len > 65536)
 473                 uc_len = 65536;
 474         for (i = 0; (u32)i < uc_len; i++)
 475                 uc[i] = cpu_to_le16(i);
 476         for (r = 0; uc_run_table[r][0]; r++) {
 477                 off = uc_run_table[r][2];
 478                 for (i = uc_run_table[r][0]; i < uc_run_table[r][1]; i++)
 479                         uc[i] = cpu_to_le16(i + off);
 480         }
 481         for (r = 0; uc_dup_table[r][0]; r++)
 482                 for (i = uc_dup_table[r][0]; i < uc_dup_table[r][1]; i += 2)
 483                         uc[i + 1] = cpu_to_le16(i);
 484         for (r = 0; uc_byte_table[r][0]; r++) {
 485                 k = uc_byte_table[r][1];
 486                 uc[uc_byte_table[r][0]] = cpu_to_le16(k);
 487         }
 488 }
 489
 490 static utf16lechar upcase[65536];
 491
 492 void
 493 init_upcase(void)
 494 {
 495         ntfs_upcase_table_build(upcase, ARRAY_LEN(upcase));
 496 }
 497
 498 /* Compare UTF-16LE strings case-sensitively (%ignore_case == false) or
 499  * case-insensitively (%ignore_case == true).
 500  *
 501  * This is implemented using the default upper-case table used by NTFS.  It does
 502  * not handle all possible cases allowed by UTF-16LE.  For example, different
 503  * normalizations of the same sequence of "characters" are not considered equal.
 504  * It hopefully does the right thing most of the time though.  */
 505 int
 506 cmp_utf16le_strings(const utf16lechar *s1, size_t n1,
 507                     const utf16lechar *s2, size_t n2,
 508                     bool ignore_case)
 509 {
 510         size_t n = min(n1, n2);
 511
 512         if (ignore_case) {
 513                 for (size_t i = 0; i < n; i++) {
 514                         u16 c1 = le16_to_cpu(upcase[le16_to_cpu(s1[i])]);
 515                         u16 c2 = le16_to_cpu(upcase[le16_to_cpu(s2[i])]);
 516                         if (c1 != c2)
 517                                 return (c1 < c2) ? -1 : 1;
 518                 }
 519         } else {
 520                 for (size_t i = 0; i < n; i++) {
 521                         u16 c1 = le16_to_cpu(s1[i]);
 522                         u16 c2 = le16_to_cpu(s2[i]);
 523                         if (c1 != c2)
 524                                 return (c1 < c2) ? -1 : 1;
 525                 }
 526         }
 527         if (n1 == n2)
 528                 return 0;
 529         return (n1 < n2) ? -1 : 1;
 530 }
 531
 532 /* Duplicates a string of system-dependent encoding into a UTF-16LE string and
 533  * returns the string and its length, in bytes, in the pointer arguments.  Frees
 534  * any existing string at the return location before overwriting it. */
 535 int
 536 get_utf16le_string(const tchar *name, utf16lechar **name_utf16le_ret,
 537                    u16 *name_utf16le_nbytes_ret)
 538 {
 539         utf16lechar *name_utf16le;
 540         size_t name_utf16le_nbytes;
 541         int ret;
 542 #if TCHAR_IS_UTF16LE
 543         name_utf16le_nbytes = tstrlen(name) * sizeof(utf16lechar);
 544         name_utf16le = MALLOC(name_utf16le_nbytes + sizeof(utf16lechar));
 545         if (name_utf16le == NULL)
 546                 return WIMLIB_ERR_NOMEM;
 547         memcpy(name_utf16le, name, name_utf16le_nbytes + sizeof(utf16lechar));
 548         ret = 0;
 549 #else
 550
 551         ret = tstr_to_utf16le(name, tstrlen(name), &name_utf16le,
 552                               &name_utf16le_nbytes);
 553         if (ret == 0) {
 554                 if (name_utf16le_nbytes > 0xffff) {
 555                         FREE(name_utf16le);
 556                         ERROR("Multibyte string \"%"TS"\" is too long!", name);
 557                         ret = WIMLIB_ERR_INVALID_UTF8_STRING;
 558                 }
 559         }
 560 #endif
 561         if (ret == 0) {
 562                 FREE(*name_utf16le_ret);
 563                 *name_utf16le_ret = name_utf16le;
 564                 *name_utf16le_nbytes_ret = name_utf16le_nbytes;
 565         }
 566         return ret;
 567 }
 568