linux/fs/udf/unicode.c
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   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/crc-itu-t.h>
  27#include <linux/slab.h>
  28
  29#include "udf_sb.h"
  30
  31static int udf_translate_to_linux(uint8_t *, uint8_t *, int, uint8_t *, int);
  32
  33static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen)
  34{
  35        if ((!dest) || (!src) || (!strlen) || (strlen > UDF_NAME_LEN - 2))
  36                return 0;
  37
  38        memset(dest, 0, sizeof(struct ustr));
  39        memcpy(dest->u_name, src, strlen);
  40        dest->u_cmpID = 0x08;
  41        dest->u_len = strlen;
  42
  43        return strlen;
  44}
  45
  46/*
  47 * udf_build_ustr
  48 */
  49int udf_build_ustr(struct ustr *dest, dstring *ptr, int size)
  50{
  51        int usesize;
  52
  53        if (!dest || !ptr || !size)
  54                return -1;
  55        BUG_ON(size < 2);
  56
  57        usesize = min_t(size_t, ptr[size - 1], sizeof(dest->u_name));
  58        usesize = min(usesize, size - 2);
  59        dest->u_cmpID = ptr[0];
  60        dest->u_len = usesize;
  61        memcpy(dest->u_name, ptr + 1, usesize);
  62        memset(dest->u_name + usesize, 0, sizeof(dest->u_name) - usesize);
  63
  64        return 0;
  65}
  66
  67/*
  68 * udf_build_ustr_exact
  69 */
  70static int udf_build_ustr_exact(struct ustr *dest, dstring *ptr, int exactsize)
  71{
  72        if ((!dest) || (!ptr) || (!exactsize))
  73                return -1;
  74
  75        memset(dest, 0, sizeof(struct ustr));
  76        dest->u_cmpID = ptr[0];
  77        dest->u_len = exactsize - 1;
  78        memcpy(dest->u_name, ptr + 1, exactsize - 1);
  79
  80        return 0;
  81}
  82
  83/*
  84 * udf_ocu_to_utf8
  85 *
  86 * PURPOSE
  87 *      Convert OSTA Compressed Unicode to the UTF-8 equivalent.
  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 */
 102int udf_CS0toUTF8(struct ustr *utf_o, const struct ustr *ocu_i)
 103{
 104        const uint8_t *ocu;
 105        uint8_t cmp_id, ocu_len;
 106        int i;
 107
 108        ocu_len = ocu_i->u_len;
 109        if (ocu_len == 0) {
 110                memset(utf_o, 0, sizeof(struct ustr));
 111                return 0;
 112        }
 113
 114        cmp_id = ocu_i->u_cmpID;
 115        if (cmp_id != 8 && cmp_id != 16) {
 116                memset(utf_o, 0, sizeof(struct ustr));
 117                pr_err("unknown compression code (%d) stri=%s\n",
 118                       cmp_id, ocu_i->u_name);
 119                return 0;
 120        }
 121
 122        ocu = ocu_i->u_name;
 123        utf_o->u_len = 0;
 124        for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
 125
 126                /* Expand OSTA compressed Unicode to Unicode */
 127                uint32_t c = ocu[i++];
 128                if (cmp_id == 16)
 129                        c = (c << 8) | ocu[i++];
 130
 131                /* Compress Unicode to UTF-8 */
 132                if (c < 0x80U)
 133                        utf_o->u_name[utf_o->u_len++] = (uint8_t)c;
 134                else if (c < 0x800U) {
 135                        utf_o->u_name[utf_o->u_len++] =
 136                                                (uint8_t)(0xc0 | (c >> 6));
 137                        utf_o->u_name[utf_o->u_len++] =
 138                                                (uint8_t)(0x80 | (c & 0x3f));
 139                } else {
 140                        utf_o->u_name[utf_o->u_len++] =
 141                                                (uint8_t)(0xe0 | (c >> 12));
 142                        utf_o->u_name[utf_o->u_len++] =
 143                                                (uint8_t)(0x80 |
 144                                                          ((c >> 6) & 0x3f));
 145                        utf_o->u_name[utf_o->u_len++] =
 146                                                (uint8_t)(0x80 | (c & 0x3f));
 147                }
 148        }
 149        utf_o->u_cmpID = 8;
 150
 151        return utf_o->u_len;
 152}
 153
 154/*
 155 *
 156 * udf_utf8_to_ocu
 157 *
 158 * PURPOSE
 159 *      Convert UTF-8 to the OSTA Compressed Unicode equivalent.
 160 *
 161 * DESCRIPTION
 162 *      This routine is only called by udf_lookup().
 163 *
 164 * PRE-CONDITIONS
 165 *      ocu                     Pointer to OSTA Compressed Unicode output
 166 *                              buffer of size UDF_NAME_LEN bytes.
 167 *      utf                     Pointer to UTF-8 input buffer.
 168 *      utf_len                 Length of UTF-8 input buffer in bytes.
 169 *
 170 * POST-CONDITIONS
 171 *      <return>                Zero on success.
 172 *
 173 * HISTORY
 174 *      November 12, 1997 - Andrew E. Mileski
 175 *      Written, tested, and released.
 176 */
 177static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length)
 178{
 179        unsigned c, i, max_val, utf_char;
 180        int utf_cnt, u_len;
 181
 182        memset(ocu, 0, sizeof(dstring) * length);
 183        ocu[0] = 8;
 184        max_val = 0xffU;
 185
 186try_again:
 187        u_len = 0U;
 188        utf_char = 0U;
 189        utf_cnt = 0U;
 190        for (i = 0U; i < utf->u_len; i++) {
 191                c = (uint8_t)utf->u_name[i];
 192
 193                /* Complete a multi-byte UTF-8 character */
 194                if (utf_cnt) {
 195                        utf_char = (utf_char << 6) | (c & 0x3fU);
 196                        if (--utf_cnt)
 197                                continue;
 198                } else {
 199                        /* Check for a multi-byte UTF-8 character */
 200                        if (c & 0x80U) {
 201                                /* Start a multi-byte UTF-8 character */
 202                                if ((c & 0xe0U) == 0xc0U) {
 203                                        utf_char = c & 0x1fU;
 204                                        utf_cnt = 1;
 205                                } else if ((c & 0xf0U) == 0xe0U) {
 206                                        utf_char = c & 0x0fU;
 207                                        utf_cnt = 2;
 208                                } else if ((c & 0xf8U) == 0xf0U) {
 209                                        utf_char = c & 0x07U;
 210                                        utf_cnt = 3;
 211                                } else if ((c & 0xfcU) == 0xf8U) {
 212                                        utf_char = c & 0x03U;
 213                                        utf_cnt = 4;
 214                                } else if ((c & 0xfeU) == 0xfcU) {
 215                                        utf_char = c & 0x01U;
 216                                        utf_cnt = 5;
 217                                } else {
 218                                        goto error_out;
 219                                }
 220                                continue;
 221                        } else {
 222                                /* Single byte UTF-8 character (most common) */
 223                                utf_char = c;
 224                        }
 225                }
 226
 227                /* Choose no compression if necessary */
 228                if (utf_char > max_val) {
 229                        if (max_val == 0xffU) {
 230                                max_val = 0xffffU;
 231                                ocu[0] = (uint8_t)0x10U;
 232                                goto try_again;
 233                        }
 234                        goto error_out;
 235                }
 236
 237                if (max_val == 0xffffU)
 238                        ocu[++u_len] = (uint8_t)(utf_char >> 8);
 239                ocu[++u_len] = (uint8_t)(utf_char & 0xffU);
 240        }
 241
 242        if (utf_cnt) {
 243error_out:
 244                ocu[++u_len] = '?';
 245                printk(KERN_DEBUG pr_fmt("bad UTF-8 character\n"));
 246        }
 247
 248        ocu[length - 1] = (uint8_t)u_len + 1;
 249
 250        return u_len + 1;
 251}
 252
 253static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
 254                        const struct ustr *ocu_i)
 255{
 256        const uint8_t *ocu;
 257        uint8_t cmp_id, ocu_len;
 258        int i, len;
 259
 260
 261        ocu_len = ocu_i->u_len;
 262        if (ocu_len == 0) {
 263                memset(utf_o, 0, sizeof(struct ustr));
 264                return 0;
 265        }
 266
 267        cmp_id = ocu_i->u_cmpID;
 268        if (cmp_id != 8 && cmp_id != 16) {
 269                memset(utf_o, 0, sizeof(struct ustr));
 270                pr_err("unknown compression code (%d) stri=%s\n",
 271                       cmp_id, ocu_i->u_name);
 272                return 0;
 273        }
 274
 275        ocu = ocu_i->u_name;
 276        utf_o->u_len = 0;
 277        for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
 278                /* Expand OSTA compressed Unicode to Unicode */
 279                uint32_t c = ocu[i++];
 280                if (cmp_id == 16)
 281                        c = (c << 8) | ocu[i++];
 282
 283                len = nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
 284                                    UDF_NAME_LEN - utf_o->u_len);
 285                /* Valid character? */
 286                if (len >= 0)
 287                        utf_o->u_len += len;
 288                else
 289                        utf_o->u_name[utf_o->u_len++] = '?';
 290        }
 291        utf_o->u_cmpID = 8;
 292
 293        return utf_o->u_len;
 294}
 295
 296static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
 297                        int length)
 298{
 299        int len;
 300        unsigned 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
 308try_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)
 313                        continue;
 314                /* Invalid character, deal with it */
 315                if (len < 0) {
 316                        len = 1;
 317                        uni_char = '?';
 318                }
 319
 320                if (uni_char > max_val) {
 321                        max_val = 0xffffU;
 322                        ocu[0] = (uint8_t)0x10U;
 323                        goto try_again;
 324                }
 325
 326                if (max_val == 0xffffU)
 327                        ocu[++u_len] = (uint8_t)(uni_char >> 8);
 328                ocu[++u_len] = (uint8_t)(uni_char & 0xffU);
 329                i += len - 1;
 330        }
 331
 332        ocu[length - 1] = (uint8_t)u_len + 1;
 333        return u_len + 1;
 334}
 335
 336int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname,
 337                     int flen)
 338{
 339        struct ustr *filename, *unifilename;
 340        int len = 0;
 341
 342        filename = kmalloc(sizeof(struct ustr), GFP_NOFS);
 343        if (!filename)
 344                return 0;
 345
 346        unifilename = kmalloc(sizeof(struct ustr), GFP_NOFS);
 347        if (!unifilename)
 348                goto out1;
 349
 350        if (udf_build_ustr_exact(unifilename, sname, flen))
 351                goto out2;
 352
 353        if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
 354                if (!udf_CS0toUTF8(filename, unifilename)) {
 355                        udf_debug("Failed in udf_get_filename: sname = %s\n",
 356                                  sname);
 357                        goto out2;
 358                }
 359        } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
 360                if (!udf_CS0toNLS(UDF_SB(sb)->s_nls_map, filename,
 361                                  unifilename)) {
 362                        udf_debug("Failed in udf_get_filename: sname = %s\n",
 363                                  sname);
 364                        goto out2;
 365                }
 366        } else
 367                goto out2;
 368
 369        len = udf_translate_to_linux(dname, filename->u_name, filename->u_len,
 370                                     unifilename->u_name, unifilename->u_len);
 371out2:
 372        kfree(unifilename);
 373out1:
 374        kfree(filename);
 375        return len;
 376}
 377
 378int udf_put_filename(struct super_block *sb, const uint8_t *sname,
 379                     uint8_t *dname, int flen)
 380{
 381        struct ustr unifilename;
 382        int namelen;
 383
 384        if (!udf_char_to_ustr(&unifilename, sname, flen))
 385                return 0;
 386
 387        if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
 388                namelen = udf_UTF8toCS0(dname, &unifilename, UDF_NAME_LEN);
 389                if (!namelen)
 390                        return 0;
 391        } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
 392                namelen = udf_NLStoCS0(UDF_SB(sb)->s_nls_map, dname,
 393                                        &unifilename, UDF_NAME_LEN);
 394                if (!namelen)
 395                        return 0;
 396        } else
 397                return 0;
 398
 399        return namelen;
 400}
 401
 402#define ILLEGAL_CHAR_MARK       '_'
 403#define EXT_MARK                '.'
 404#define CRC_MARK                '#'
 405#define EXT_SIZE                5
 406
 407static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName,
 408                                  int udfLen, uint8_t *fidName,
 409                                  int fidNameLen)
 410{
 411        int index, newIndex = 0, needsCRC = 0;
 412        int extIndex = 0, newExtIndex = 0, hasExt = 0;
 413        unsigned short valueCRC;
 414        uint8_t curr;
 415        const uint8_t hexChar[] = "0123456789ABCDEF";
 416
 417        if (udfName[0] == '.' &&
 418            (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
 419                needsCRC = 1;
 420                newIndex = udfLen;
 421                memcpy(newName, udfName, udfLen);
 422        } else {
 423                for (index = 0; index < udfLen; index++) {
 424                        curr = udfName[index];
 425                        if (curr == '/' || curr == 0) {
 426                                needsCRC = 1;
 427                                curr = ILLEGAL_CHAR_MARK;
 428                                while (index + 1 < udfLen &&
 429                                                (udfName[index + 1] == '/' ||
 430                                                 udfName[index + 1] == 0))
 431                                        index++;
 432                        }
 433                        if (curr == EXT_MARK &&
 434                                        (udfLen - index - 1) <= EXT_SIZE) {
 435                                if (udfLen == index + 1)
 436                                        hasExt = 0;
 437                                else {
 438                                        hasExt = 1;
 439                                        extIndex = index;
 440                                        newExtIndex = newIndex;
 441                                }
 442                        }
 443                        if (newIndex < 256)
 444                                newName[newIndex++] = curr;
 445                        else
 446                                needsCRC = 1;
 447                }
 448        }
 449        if (needsCRC) {
 450                uint8_t ext[EXT_SIZE];
 451                int localExtIndex = 0;
 452
 453                if (hasExt) {
 454                        int maxFilenameLen;
 455                        for (index = 0;
 456                             index < EXT_SIZE && extIndex + index + 1 < udfLen;
 457                             index++) {
 458                                curr = udfName[extIndex + index + 1];
 459
 460                                if (curr == '/' || curr == 0) {
 461                                        needsCRC = 1;
 462                                        curr = ILLEGAL_CHAR_MARK;
 463                                        while (extIndex + index + 2 < udfLen &&
 464                                              (index + 1 < EXT_SIZE &&
 465                                                (udfName[extIndex + index + 2] == '/' ||
 466                                                 udfName[extIndex + index + 2] == 0)))
 467                                                index++;
 468                                }
 469                                ext[localExtIndex++] = curr;
 470                        }
 471                        maxFilenameLen = 250 - localExtIndex;
 472                        if (newIndex > maxFilenameLen)
 473                                newIndex = maxFilenameLen;
 474                        else
 475                                newIndex = newExtIndex;
 476                } else if (newIndex > 250)
 477                        newIndex = 250;
 478                newName[newIndex++] = CRC_MARK;
 479                valueCRC = crc_itu_t(0, fidName, fidNameLen);
 480                newName[newIndex++] = hexChar[(valueCRC & 0xf000) >> 12];
 481                newName[newIndex++] = hexChar[(valueCRC & 0x0f00) >> 8];
 482                newName[newIndex++] = hexChar[(valueCRC & 0x00f0) >> 4];
 483                newName[newIndex++] = hexChar[(valueCRC & 0x000f)];
 484
 485                if (hasExt) {
 486                        newName[newIndex++] = EXT_MARK;
 487                        for (index = 0; index < localExtIndex; index++)
 488                                newName[newIndex++] = ext[index];
 489                }
 490        }
 491
 492        return newIndex;
 493}
 494
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