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 #include <linux/udf_fs.h>
  27
  28 #include "udf_sb.h"
  29
  30 static int udf_translate_to_linux(uint8_t *, uint8_t *, int, uint8_t *, int);
  31
  32 static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen)
  33 {
  34         if ( (!dest) || (!src) || (!strlen) || (strlen > UDF_NAME_LEN-2) )
  35                 return 0;
  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         return strlen;
  41 }
  42
  43 /*
  44  * udf_build_ustr
  45  */
  46 int udf_build_ustr(struct ustr *dest, dstring *ptr, int size)
  47 {
  48         int usesize;
  49
  50         if ( (!dest) || (!ptr) || (!size) )
  51                 return -1;
  52
  53         memset(dest, 0, sizeof(struct ustr));
  54         usesize= (size > UDF_NAME_LEN) ? UDF_NAME_LEN : size;
  55         dest->u_cmpID=ptr[0];
  56         dest->u_len=ptr[size-1];
  57         memcpy(dest->u_name, ptr+1, usesize-1);
  58         return 0;
  59 }
  60
  61 /*
  62  * udf_build_ustr_exact
  63  */
  64 static int udf_build_ustr_exact(struct ustr *dest, dstring *ptr, int exactsize)
  65 {
  66         if ( (!dest) || (!ptr) || (!exactsize) )
  67                 return -1;
  68
  69         memset(dest, 0, sizeof(struct ustr));
  70         dest->u_cmpID=ptr[0];
  71         dest->u_len=exactsize-1;
  72         memcpy(dest->u_name, ptr+1, exactsize-1);
  73         return 0;
  74 }
  75
  76 /*
  77  * udf_ocu_to_utf8
  78  *
  79  * PURPOSE
  80  *      Convert OSTA Compressed Unicode to the UTF-8 equivalent.
  81  *
  82  * DESCRIPTION
  83  *      This routine is only called by udf_filldir().
  84  *
  85  * PRE-CONDITIONS
  86  *      utf                     Pointer to UTF-8 output buffer.
  87  *      ocu                     Pointer to OSTA Compressed Unicode input buffer
  88  *                              of size UDF_NAME_LEN bytes.
  89  *                              both of type "struct ustr *"
  90  *
  91  * POST-CONDITIONS
  92  *      <return>                Zero on success.
  93  *
  94  * HISTORY
  95  *      November 12, 1997 - Andrew E. Mileski
  96  *      Written, tested, and released.
  97  */
  98 int udf_CS0toUTF8(struct ustr *utf_o, struct ustr *ocu_i)
  99 {
 100         uint8_t *ocu;
 101         uint32_t c;
 102         uint8_t cmp_id, ocu_len;
 103         int i;
 104
 105         ocu = ocu_i->u_name;
 106
 107         ocu_len = ocu_i->u_len;
 108         cmp_id = ocu_i->u_cmpID;
 109         utf_o->u_len = 0;
 110
 111         if (ocu_len == 0)
 112         {
 113                 memset(utf_o, 0, sizeof(struct ustr));
 114                 utf_o->u_cmpID = 0;
 115                 utf_o->u_len = 0;
 116                 return 0;
 117         }
 118
 119         if ((cmp_id != 8) && (cmp_id != 16))
 120         {
 121                 printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n", cmp_id, ocu_i->u_name);
 122                 return 0;
 123         }
 124
 125         for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN-3)) ;)
 126         {
 127
 128                 /* Expand OSTA compressed Unicode to Unicode */
 129                 c = ocu[i++];
 130                 if (cmp_id == 16)
 131                         c = (c << 8) | ocu[i++];
 132
 133                 /* Compress Unicode to UTF-8 */
 134                 if (c < 0x80U)
 135                         utf_o->u_name[utf_o->u_len++] = (uint8_t)c;
 136                 else if (c < 0x800U)
 137                 {
 138                         utf_o->u_name[utf_o->u_len++] = (uint8_t)(0xc0 | (c >> 6));
 139                         utf_o->u_name[utf_o->u_len++] = (uint8_t)(0x80 | (c & 0x3f));
 140                 }
 141                 else
 142                 {
 143                         utf_o->u_name[utf_o->u_len++] = (uint8_t)(0xe0 | (c >> 12));
 144                         utf_o->u_name[utf_o->u_len++] = (uint8_t)(0x80 | ((c >> 6) & 0x3f));
 145                         utf_o->u_name[utf_o->u_len++] = (uint8_t)(0x80 | (c & 0x3f));
 146                 }
 147         }
 148         utf_o->u_cmpID=8;
 149
 150         return utf_o->u_len;
 151 }
 152
 153 /*
 154  *
 155  * udf_utf8_to_ocu
 156  *
 157  * PURPOSE
 158  *      Convert UTF-8 to the OSTA Compressed Unicode equivalent.
 159  *
 160  * DESCRIPTION
 161  *      This routine is only called by udf_lookup().
 162  *
 163  * PRE-CONDITIONS
 164  *      ocu                     Pointer to OSTA Compressed Unicode output
 165  *                              buffer of size UDF_NAME_LEN bytes.
 166  *      utf                     Pointer to UTF-8 input buffer.
 167  *      utf_len                 Length of UTF-8 input buffer in bytes.
 168  *
 169  * POST-CONDITIONS
 170  *      <return>                Zero on success.
 171  *
 172  * HISTORY
 173  *      November 12, 1997 - Andrew E. Mileski
 174  *      Written, tested, and released.
 175  */
 176 static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length)
 177 {
 178         unsigned c, i, max_val, utf_char;
 179         int utf_cnt, u_len;
 180
 181         memset(ocu, 0, sizeof(dstring) * length);
 182         ocu[0] = 8;
 183         max_val = 0xffU;
 184
 185 try_again:
 186         u_len = 0U;
 187         utf_char = 0U;
 188         utf_cnt = 0U;
 189         for (i = 0U; i < utf->u_len; i++)
 190         {
 191                 c = (uint8_t)utf->u_name[i];
 192
 193                 /* Complete a multi-byte UTF-8 character */
 194                 if (utf_cnt)
 195                 {
 196                         utf_char = (utf_char << 6) | (c & 0x3fU);
 197                         if (--utf_cnt)
 198                                 continue;
 199                 }
 200                 else
 201                 {
 202                         /* Check for a multi-byte UTF-8 character */
 203                         if (c & 0x80U)
 204                         {
 205                                 /* Start a multi-byte UTF-8 character */
 206                                 if ((c & 0xe0U) == 0xc0U)
 207                                 {
 208                                         utf_char = c & 0x1fU;
 209                                         utf_cnt = 1;
 210                                 }
 211                                 else if ((c & 0xf0U) == 0xe0U)
 212                                 {
 213                                         utf_char = c & 0x0fU;
 214                                         utf_cnt = 2;
 215                                 }
 216                                 else if ((c & 0xf8U) == 0xf0U)
 217                                 {
 218                                         utf_char = c & 0x07U;
 219                                         utf_cnt = 3;
 220                                 }
 221                                 else if ((c & 0xfcU) == 0xf8U)
 222                                 {
 223                                         utf_char = c & 0x03U;
 224                                         utf_cnt = 4;
 225                                 }
 226                                 else if ((c & 0xfeU) == 0xfcU)
 227                                 {
 228                                         utf_char = c & 0x01U;
 229                                         utf_cnt = 5;
 230                                 }
 231                                 else
 232                                         goto error_out;
 233                                 continue;
 234                         } else
 235                                 /* Single byte UTF-8 character (most common) */
 236                                 utf_char = c;
 237                 }
 238
 239                 /* Choose no compression if necessary */
 240                 if (utf_char > max_val)
 241                 {
 242                         if ( 0xffU == max_val )
 243                         {
 244                                 max_val = 0xffffU;
 245                                 ocu[0] = (uint8_t)0x10U;
 246                                 goto try_again;
 247                         }
 248                         goto error_out;
 249                 }
 250
 251                 if (max_val == 0xffffU)
 252                 {
 253                         ocu[++u_len] = (uint8_t)(utf_char >> 8);
 254                 }
 255                 ocu[++u_len] = (uint8_t)(utf_char & 0xffU);
 256         }
 257
 258
 259         if (utf_cnt)
 260         {
 261 error_out:
 262                 ocu[++u_len] = '?';
 263                 printk(KERN_DEBUG "udf: bad UTF-8 character\n");
 264         }
 265
 266         ocu[length - 1] = (uint8_t)u_len + 1;
 267         return u_len + 1;
 268 }
 269
 270 static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o, struct ustr *ocu_i)
 271 {
 272         uint8_t *ocu;
 273         uint32_t c;
 274         uint8_t cmp_id, ocu_len;
 275         int i;
 276
 277         ocu = ocu_i->u_name;
 278
 279         ocu_len = ocu_i->u_len;
 280         cmp_id = ocu_i->u_cmpID;
 281         utf_o->u_len = 0;
 282
 283         if (ocu_len == 0)
 284         {
 285                 memset(utf_o, 0, sizeof(struct ustr));
 286                 utf_o->u_cmpID = 0;
 287                 utf_o->u_len = 0;
 288                 return 0;
 289         }
 290
 291         if ((cmp_id != 8) && (cmp_id != 16))
 292         {
 293                 printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n", cmp_id, ocu_i->u_name);
 294                 return 0;
 295         }
 296
 297         for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN-3)) ;)
 298         {
 299                 /* Expand OSTA compressed Unicode to Unicode */
 300                 c = ocu[i++];
 301                 if (cmp_id == 16)
 302                         c = (c << 8) | ocu[i++];
 303
 304                 utf_o->u_len += nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
 305                         UDF_NAME_LEN - utf_o->u_len);
 306         }
 307         utf_o->u_cmpID=8;
 308
 309         return utf_o->u_len;
 310 }
 311
 312 static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni, int length)
 313 {
 314         unsigned len, i, max_val;
 315         uint16_t uni_char;
 316         int u_len;
 317
 318         memset(ocu, 0, sizeof(dstring) * length);
 319         ocu[0] = 8;
 320         max_val = 0xffU;
 321
 322 try_again:
 323         u_len = 0U;
 324         for (i = 0U; i < uni->u_len; i++)
 325         {
 326                 len = nls->char2uni(&uni->u_name[i], uni->u_len-i, &uni_char);
 327                 if (len <= 0)
 328                         continue;
 329
 330                 if (uni_char > max_val)
 331                 {
 332                         max_val = 0xffffU;
 333                         ocu[0] = (uint8_t)0x10U;
 334                         goto try_again;
 335                 }
 336
 337                 if (max_val == 0xffffU)
 338                         ocu[++u_len] = (uint8_t)(uni_char >> 8);
 339                 ocu[++u_len] = (uint8_t)(uni_char & 0xffU);
 340                 i += len - 1;
 341         }
 342
 343         ocu[length - 1] = (uint8_t)u_len + 1;
 344         return u_len + 1;
 345 }
 346
 347 int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname, int flen)
 348 {
 349         struct ustr filename, unifilename;
 350         int len;
 351
 352         if (udf_build_ustr_exact(&unifilename, sname, flen))
 353         {
 354                 return 0;
 355         }
 356
 357         if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8))
 358         {
 359                 if (!udf_CS0toUTF8(&filename, &unifilename) )
 360                 {
 361                         udf_debug("Failed in udf_get_filename: sname = %s\n", sname);
 362                         return 0;
 363                 }
 364         }
 365         else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
 366         {
 367                 if (!udf_CS0toNLS(UDF_SB(sb)->s_nls_map, &filename, &unifilename) )
 368                 {
 369                         udf_debug("Failed in udf_get_filename: sname = %s\n", sname);
 370                         return 0;
 371                 }
 372         }
 373         else
 374                 return 0;
 375
 376         if ((len = udf_translate_to_linux(dname, filename.u_name, filename.u_len,
 377                 unifilename.u_name, unifilename.u_len)))
 378         {
 379                 return len;
 380         }
 381         return 0;
 382 }
 383
 384 int udf_put_filename(struct super_block *sb, const uint8_t *sname, uint8_t *dname, int flen)
 385 {
 386         struct ustr unifilename;
 387         int namelen;
 388
 389         if ( !(udf_char_to_ustr(&unifilename, sname, flen)) )
 390         {
 391                 return 0;
 392         }
 393
 394         if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8))
 395         {
 396                 if ( !(namelen = udf_UTF8toCS0(dname, &unifilename, UDF_NAME_LEN)) )
 397                 {
 398                         return 0;
 399                 }
 400         }
 401         else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
 402         {
 403                 if ( !(namelen = udf_NLStoCS0(UDF_SB(sb)->s_nls_map, dname, &unifilename, UDF_NAME_LEN)) )
 404                 {
 405                         return 0;
 406                 }
 407         }
 408         else
 409                 return 0;
 410
 411         return namelen;
 412 }
 413
 414 #define ILLEGAL_CHAR_MARK       '_'
 415 #define EXT_MARK                        '.'
 416 #define CRC_MARK                        '#'
 417 #define EXT_SIZE                        5
 418
 419 static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName, int udfLen, uint8_t *fidName, int fidNameLen)
 420 {
 421         int index, newIndex = 0, needsCRC = 0;
 422         int extIndex = 0, newExtIndex = 0, hasExt = 0;
 423         unsigned short valueCRC;
 424         uint8_t curr;
 425         const uint8_t hexChar[] = "0123456789ABCDEF";
 426
 427         if (udfName[0] == '.' && (udfLen == 1 ||
 428                 (udfLen == 2 && udfName[1] == '.')))
 429         {
 430                 needsCRC = 1;
 431                 newIndex = udfLen;
 432                 memcpy(newName, udfName, udfLen);
 433         }
 434         else
 435         {
 436                 for (index = 0; index < udfLen; index++)
 437                 {
 438                         curr = udfName[index];
 439                         if (curr == '/' || curr == 0)
 440                         {
 441                                 needsCRC = 1;
 442                                 curr = ILLEGAL_CHAR_MARK;
 443                                 while (index+1 < udfLen && (udfName[index+1] == '/' ||
 444                                         udfName[index+1] == 0))
 445                                         index++;
 446                         }
 447                         if (curr == EXT_MARK && (udfLen - index - 1) <= EXT_SIZE)
 448                         {
 449                                 if (udfLen == index + 1)
 450                                         hasExt = 0;
 451                                 else
 452                                 {
 453                                         hasExt = 1;
 454                                         extIndex = index;
 455                                         newExtIndex = newIndex;
 456                                 }
 457                         }
 458                         if (newIndex < 256)
 459                                 newName[newIndex++] = curr;
 460                         else
 461                                 needsCRC = 1;
 462                 }
 463         }
 464         if (needsCRC)
 465         {
 466                 uint8_t ext[EXT_SIZE];
 467                 int localExtIndex = 0;
 468
 469                 if (hasExt)
 470                 {
 471                         int maxFilenameLen;
 472                         for(index = 0; index<EXT_SIZE && extIndex + index +1 < udfLen;
 473                                 index++ )
 474                         {
 475                                 curr = udfName[extIndex + index + 1];
 476
 477                                 if (curr == '/' || curr == 0)
 478                                 {
 479                                         needsCRC = 1;
 480                                         curr = ILLEGAL_CHAR_MARK;
 481                                         while(extIndex + index + 2 < udfLen && (index + 1 < EXT_SIZE
 482                                                 && (udfName[extIndex + index + 2] == '/' ||
 483                                                         udfName[extIndex + index + 2] == 0)))
 484                                                 index++;
 485                                 }
 486                                 ext[localExtIndex++] = curr;
 487                         }
 488                         maxFilenameLen = 250 - localExtIndex;
 489                         if (newIndex > maxFilenameLen)
 490                                 newIndex = maxFilenameLen;
 491                         else
 492                                 newIndex = newExtIndex;
 493                 }
 494                 else if (newIndex > 250)
 495                         newIndex = 250;
 496                 newName[newIndex++] = CRC_MARK;
 497                 valueCRC = udf_crc(fidName, fidNameLen, 0);
 498                 newName[newIndex++] = hexChar[(valueCRC & 0xf000) >> 12];
 499                 newName[newIndex++] = hexChar[(valueCRC & 0x0f00) >> 8];
 500                 newName[newIndex++] = hexChar[(valueCRC & 0x00f0) >> 4];
 501                 newName[newIndex++] = hexChar[(valueCRC & 0x000f)];
 502
 503                 if (hasExt)
 504                 {
 505                         newName[newIndex++] = EXT_MARK;
 506                         for (index = 0;index < localExtIndex ;index++ )
 507                                 newName[newIndex++] = ext[index];
 508                 }
 509         }
 510         return newIndex;
 511 }