Pileus Git - ~andy/linux/blob - fs/udf/unicode.c

   1 /*
   2  * unicode.c
   3  *
   4  * PURPOSE
   5  *      Routines for converting between UTF-8 and OSTA Compressed Unicode.
   6  *      Also handles filename mangling
   7  *
   8  * DESCRIPTION
   9  *      OSTA Compressed Unicode is explained in the OSTA UDF specification.
  10  *              http://www.osta.org/
  11  *      UTF-8 is explained in the IETF RFC XXXX.
  12  *              ftp://ftp.internic.net/rfc/rfcxxxx.txt
  13  *
  14  * COPYRIGHT
  15  *      This file is distributed under the terms of the GNU General Public
  16  *      License (GPL). Copies of the GPL can be obtained from:
  17  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  18  *      Each contributing author retains all rights to their own work.
  19  */
  20
  21 #include "udfdecl.h"
  22
  23 #include <linux/kernel.h>
  24 #include <linux/string.h>       /* for memset */
  25 #include <linux/nls.h>
  26
  27 #include "udf_sb.h"
  28
  29 static int udf_translate_to_linux(uint8_t *, uint8_t *, int, uint8_t *, int);
  30
  31 static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen)
  32 {
  33         if ((!dest) || (!src) || (!strlen) || (strlen > UDF_NAME_LEN - 2))
  34                 return 0;
  35
  36         memset(dest, 0, sizeof(struct ustr));
  37         memcpy(dest->u_name, src, strlen);
  38         dest->u_cmpID = 0x08;
  39         dest->u_len = strlen;
  40
  41         return strlen;
  42 }
  43
  44 /*
  45  * udf_build_ustr
  46  */
  47 int udf_build_ustr(struct ustr *dest, dstring *ptr, int size)
  48 {
  49         int usesize;
  50
  51         if ((!dest) || (!ptr) || (!size))
  52                 return -1;
  53
  54         memset(dest, 0, sizeof(struct ustr));
  55         usesize = (size > UDF_NAME_LEN) ? UDF_NAME_LEN : size;
  56         dest->u_cmpID = ptr[0];
  57         dest->u_len = ptr[size - 1];
  58         memcpy(dest->u_name, ptr + 1, usesize - 1);
  59
  60         return 0;
  61 }
  62
  63 /*
  64  * udf_build_ustr_exact
  65  */
  66 static int udf_build_ustr_exact(struct ustr *dest, dstring *ptr, int exactsize)
  67 {
  68         if ((!dest) || (!ptr) || (!exactsize))
  69                 return -1;
  70
  71         memset(dest, 0, sizeof(struct ustr));
  72         dest->u_cmpID = ptr[0];
  73         dest->u_len = exactsize - 1;
  74         memcpy(dest->u_name, ptr + 1, exactsize - 1);
  75
  76         return 0;
  77 }
  78
  79 /*
  80  * udf_ocu_to_utf8
  81  *
  82  * PURPOSE
  83  *      Convert OSTA Compressed Unicode to the UTF-8 equivalent.
  84  *
  85  * DESCRIPTION
  86  *      This routine is only called by udf_filldir().
  87  *
  88  * PRE-CONDITIONS
  89  *      utf                     Pointer to UTF-8 output buffer.
  90  *      ocu                     Pointer to OSTA Compressed Unicode input buffer
  91  *                              of size UDF_NAME_LEN bytes.
  92  *                              both of type "struct ustr *"
  93  *
  94  * POST-CONDITIONS
  95  *      <return>                Zero on success.
  96  *
  97  * HISTORY
  98  *      November 12, 1997 - Andrew E. Mileski
  99  *      Written, tested, and released.
 100  */
 101 int udf_CS0toUTF8(struct ustr *utf_o, struct ustr *ocu_i)
 102 {
 103         uint8_t *ocu;
 104         uint32_t c;
 105         uint8_t cmp_id, ocu_len;
 106         int i;
 107
 108         ocu = ocu_i->u_name;
 109
 110         ocu_len = ocu_i->u_len;
 111         cmp_id = ocu_i->u_cmpID;
 112         utf_o->u_len = 0;
 113
 114         if (ocu_len == 0) {
 115                 memset(utf_o, 0, sizeof(struct ustr));
 116                 utf_o->u_cmpID = 0;
 117                 utf_o->u_len = 0;
 118                 return 0;
 119         }
 120
 121         if ((cmp_id != 8) && (cmp_id != 16)) {
 122                 printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n",
 123                        cmp_id, ocu_i->u_name);
 124                 return 0;
 125         }
 126
 127         for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
 128
 129                 /* Expand OSTA compressed Unicode to Unicode */
 130                 c = ocu[i++];
 131                 if (cmp_id == 16)
 132                         c = (c << 8) | ocu[i++];
 133
 134                 /* Compress Unicode to UTF-8 */
 135                 if (c < 0x80U) {
 136                         utf_o->u_name[utf_o->u_len++] = (uint8_t)c;
 137                 } else if (c < 0x800U) {
 138                         utf_o->u_name[utf_o->u_len++] =
 139                                                 (uint8_t)(0xc0 | (c >> 6));
 140                         utf_o->u_name[utf_o->u_len++] =
 141                                                 (uint8_t)(0x80 | (c & 0x3f));
 142                 } else {
 143                         utf_o->u_name[utf_o->u_len++] =
 144                                                 (uint8_t)(0xe0 | (c >> 12));
 145                         utf_o->u_name[utf_o->u_len++] =
 146                                                 (uint8_t)(0x80 |
 147                                                           ((c >> 6) & 0x3f));
 148                         utf_o->u_name[utf_o->u_len++] =
 149                                                 (uint8_t)(0x80 | (c & 0x3f));
 150                 }
 151         }
 152         utf_o->u_cmpID = 8;
 153
 154         return utf_o->u_len;
 155 }
 156
 157 /*
 158  *
 159  * udf_utf8_to_ocu
 160  *
 161  * PURPOSE
 162  *      Convert UTF-8 to the OSTA Compressed Unicode equivalent.
 163  *
 164  * DESCRIPTION
 165  *      This routine is only called by udf_lookup().
 166  *
 167  * PRE-CONDITIONS
 168  *      ocu                     Pointer to OSTA Compressed Unicode output
 169  *                              buffer of size UDF_NAME_LEN bytes.
 170  *      utf                     Pointer to UTF-8 input buffer.
 171  *      utf_len                 Length of UTF-8 input buffer in bytes.
 172  *
 173  * POST-CONDITIONS
 174  *      <return>                Zero on success.
 175  *
 176  * HISTORY
 177  *      November 12, 1997 - Andrew E. Mileski
 178  *      Written, tested, and released.
 179  */
 180 static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length)
 181 {
 182         unsigned c, i, max_val, utf_char;
 183         int utf_cnt, u_len;
 184
 185         memset(ocu, 0, sizeof(dstring) * length);
 186         ocu[0] = 8;
 187         max_val = 0xffU;
 188
 189 try_again:
 190         u_len = 0U;
 191         utf_char = 0U;
 192         utf_cnt = 0U;
 193         for (i = 0U; i < utf->u_len; i++) {
 194                 c = (uint8_t)utf->u_name[i];
 195
 196                 /* Complete a multi-byte UTF-8 character */
 197                 if (utf_cnt) {
 198                         utf_char = (utf_char << 6) | (c & 0x3fU);
 199                         if (--utf_cnt)
 200                                 continue;
 201                 } else {
 202                         /* Check for a multi-byte UTF-8 character */
 203                         if (c & 0x80U) {
 204                                 /* Start a multi-byte UTF-8 character */
 205                                 if ((c & 0xe0U) == 0xc0U) {
 206                                         utf_char = c & 0x1fU;
 207                                         utf_cnt = 1;
 208                                 } else if ((c & 0xf0U) == 0xe0U) {
 209                                         utf_char = c & 0x0fU;
 210                                         utf_cnt = 2;
 211                                 } else if ((c & 0xf8U) == 0xf0U) {
 212                                         utf_char = c & 0x07U;
 213                                         utf_cnt = 3;
 214                                 } else if ((c & 0xfcU) == 0xf8U) {
 215                                         utf_char = c & 0x03U;
 216                                         utf_cnt = 4;
 217                                 } else if ((c & 0xfeU) == 0xfcU) {
 218                                         utf_char = c & 0x01U;
 219                                         utf_cnt = 5;
 220                                 } else {
 221                                         goto error_out;
 222                                 }
 223                                 continue;
 224                         } else {
 225                                 /* Single byte UTF-8 character (most common) */
 226                                 utf_char = c;
 227                         }
 228                 }
 229
 230                 /* Choose no compression if necessary */
 231                 if (utf_char > max_val) {
 232                         if (max_val == 0xffU) {
 233                                 max_val = 0xffffU;
 234                                 ocu[0] = (uint8_t)0x10U;
 235                                 goto try_again;
 236                         }
 237                         goto error_out;
 238                 }
 239
 240                 if (max_val == 0xffffU)
 241                         ocu[++u_len] = (uint8_t)(utf_char >> 8);
 242                 ocu[++u_len] = (uint8_t)(utf_char & 0xffU);
 243         }
 244
 245         if (utf_cnt) {
 246 error_out:
 247                 ocu[++u_len] = '?';
 248                 printk(KERN_DEBUG "udf: bad UTF-8 character\n");
 249         }
 250
 251         ocu[length - 1] = (uint8_t)u_len + 1;
 252
 253         return u_len + 1;
 254 }
 255
 256 static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
 257                         struct ustr *ocu_i)
 258 {
 259         uint8_t *ocu;
 260         uint32_t c;
 261         uint8_t cmp_id, ocu_len;
 262         int i;
 263
 264         ocu = ocu_i->u_name;
 265
 266         ocu_len = ocu_i->u_len;
 267         cmp_id = ocu_i->u_cmpID;
 268         utf_o->u_len = 0;
 269
 270         if (ocu_len == 0) {
 271                 memset(utf_o, 0, sizeof(struct ustr));
 272                 utf_o->u_cmpID = 0;
 273                 utf_o->u_len = 0;
 274                 return 0;
 275         }
 276
 277         if ((cmp_id != 8) && (cmp_id != 16)) {
 278                 printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n",
 279                        cmp_id, ocu_i->u_name);
 280                 return 0;
 281         }
 282
 283         for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
 284                 /* Expand OSTA compressed Unicode to Unicode */
 285                 c = ocu[i++];
 286                 if (cmp_id == 16)
 287                         c = (c << 8) | ocu[i++];
 288
 289                 utf_o->u_len += nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
 290                                               UDF_NAME_LEN - utf_o->u_len);
 291         }
 292         utf_o->u_cmpID = 8;
 293
 294         return utf_o->u_len;
 295 }
 296
 297 static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
 298                         int length)
 299 {
 300         unsigned len, i, max_val;
 301         uint16_t uni_char;
 302         int u_len;
 303
 304         memset(ocu, 0, sizeof(dstring) * length);
 305         ocu[0] = 8;
 306         max_val = 0xffU;
 307
 308 try_again:
 309         u_len = 0U;
 310         for (i = 0U; i < uni->u_len; i++) {
 311                 len = nls->char2uni(&uni->u_name[i], uni->u_len - i, &uni_char);
 312                 if (len <= 0)
 313                         continue;
 314
 315                 if (uni_char > max_val) {
 316                         max_val = 0xffffU;
 317                         ocu[0] = (uint8_t)0x10U;
 318                         goto try_again;
 319                 }
 320
 321                 if (max_val == 0xffffU)
 322                         ocu[++u_len] = (uint8_t)(uni_char >> 8);
 323                 ocu[++u_len] = (uint8_t)(uni_char & 0xffU);
 324                 i += len - 1;
 325         }
 326
 327         ocu[length - 1] = (uint8_t)u_len + 1;
 328         return u_len + 1;
 329 }
 330
 331 int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname,
 332                      int flen)
 333 {
 334         struct ustr filename, unifilename;
 335         int len;
 336
 337         if (udf_build_ustr_exact(&unifilename, sname, flen))
 338                 return 0;
 339
 340         if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
 341                 if (!udf_CS0toUTF8(&filename, &unifilename)) {
 342                         udf_debug("Failed in udf_get_filename: sname = %s\n",
 343                                   sname);
 344                         return 0;
 345                 }
 346         } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
 347                 if (!udf_CS0toNLS(UDF_SB(sb)->s_nls_map, &filename,
 348                                   &unifilename)) {
 349                         udf_debug("Failed in udf_get_filename: sname = %s\n",
 350                                   sname);
 351                         return 0;
 352                 }
 353         } else
 354                 return 0;
 355
 356         len = udf_translate_to_linux(dname, filename.u_name, filename.u_len,
 357                                      unifilename.u_name, unifilename.u_len);
 358         if (len)
 359                 return len;
 360
 361         return 0;
 362 }
 363
 364 int udf_put_filename(struct super_block *sb, const uint8_t *sname,
 365                      uint8_t *dname, int flen)
 366 {
 367         struct ustr unifilename;
 368         int namelen;
 369
 370         if (!udf_char_to_ustr(&unifilename, sname, flen))
 371                 return 0;
 372
 373         if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
 374                 namelen = udf_UTF8toCS0(dname, &unifilename, UDF_NAME_LEN);
 375                 if (!namelen)
 376                         return 0;
 377         } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
 378                 namelen = udf_NLStoCS0(UDF_SB(sb)->s_nls_map, dname,
 379                                         &unifilename, UDF_NAME_LEN);
 380                 if (!namelen)
 381                         return 0;
 382         } else
 383                 return 0;
 384
 385         return namelen;
 386 }
 387
 388 #define ILLEGAL_CHAR_MARK       '_'
 389 #define EXT_MARK                '.'
 390 #define CRC_MARK                '#'
 391 #define EXT_SIZE                5
 392
 393 static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName,
 394                                   int udfLen, uint8_t *fidName,
 395                                   int fidNameLen)
 396 {
 397         int index, newIndex = 0, needsCRC = 0;
 398         int extIndex = 0, newExtIndex = 0, hasExt = 0;
 399         unsigned short valueCRC;
 400         uint8_t curr;
 401         const uint8_t hexChar[] = "0123456789ABCDEF";
 402
 403         if (udfName[0] == '.' &&
 404             (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
 405                 needsCRC = 1;
 406                 newIndex = udfLen;
 407                 memcpy(newName, udfName, udfLen);
 408         } else {
 409                 for (index = 0; index < udfLen; index++) {
 410                         curr = udfName[index];
 411                         if (curr == '/' || curr == 0) {
 412                                 needsCRC = 1;
 413                                 curr = ILLEGAL_CHAR_MARK;
 414                                 while (index + 1 < udfLen &&
 415                                                 (udfName[index + 1] == '/' ||
 416                                                  udfName[index + 1] == 0))
 417                                         index++;
 418                         }
 419                         if (curr == EXT_MARK &&
 420                                         (udfLen - index - 1) <= EXT_SIZE) {
 421                                 if (udfLen == index + 1)
 422                                         hasExt = 0;
 423                                 else {
 424                                         hasExt = 1;
 425                                         extIndex = index;
 426                                         newExtIndex = newIndex;
 427                                 }
 428                         }
 429                         if (newIndex < 256)
 430                                 newName[newIndex++] = curr;
 431                         else
 432                                 needsCRC = 1;
 433                 }
 434         }
 435         if (needsCRC) {
 436                 uint8_t ext[EXT_SIZE];
 437                 int localExtIndex = 0;
 438
 439                 if (hasExt) {
 440                         int maxFilenameLen;
 441                         for (index = 0;
 442                              index < EXT_SIZE && extIndex + index + 1 < udfLen;
 443                              index++) {
 444                                 curr = udfName[extIndex + index + 1];
 445
 446                                 if (curr == '/' || curr == 0) {
 447                                         needsCRC = 1;
 448                                         curr = ILLEGAL_CHAR_MARK;
 449                                         while (extIndex + index + 2 < udfLen &&
 450                                               (index + 1 < EXT_SIZE &&
 451                                                 (udfName[extIndex + index + 2] == '/' ||
 452                                                  udfName[extIndex + index + 2] == 0)))
 453                                                 index++;
 454                                 }
 455                                 ext[localExtIndex++] = curr;
 456                         }
 457                         maxFilenameLen = 250 - localExtIndex;
 458                         if (newIndex > maxFilenameLen)
 459                                 newIndex = maxFilenameLen;
 460                         else
 461                                 newIndex = newExtIndex;
 462                 } else if (newIndex > 250)
 463                         newIndex = 250;
 464                 newName[newIndex++] = CRC_MARK;
 465                 valueCRC = udf_crc(fidName, fidNameLen, 0);
 466                 newName[newIndex++] = hexChar[(valueCRC & 0xf000) >> 12];
 467                 newName[newIndex++] = hexChar[(valueCRC & 0x0f00) >> 8];
 468                 newName[newIndex++] = hexChar[(valueCRC & 0x00f0) >> 4];
 469                 newName[newIndex++] = hexChar[(valueCRC & 0x000f)];
 470
 471                 if (hasExt) {
 472                         newName[newIndex++] = EXT_MARK;
 473                         for (index = 0; index < localExtIndex; index++)
 474                                 newName[newIndex++] = ext[index];
 475                 }
 476         }
 477
 478         return newIndex;
 479 }