cf5dd66e04f058205043421062b8908d1403e7e4
[wimlib] / src / encoding.c
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