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