fs/hfsplus/unicode.c

   1 /*
   2  *  linux/fs/hfsplus/unicode.c
   3  *
   4  * Copyright (C) 2001
   5  * Brad Boyer (flar@allandria.com)
   6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   7  *
   8  * Handler routines for unicode strings
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/nls.h>
  13 #include "hfsplus_fs.h"
  14 #include "hfsplus_raw.h"
  15
  16 /* Fold the case of a unicode char, given the 16 bit value */
  17 /* Returns folded char, or 0 if ignorable */
  18 static inline u16 case_fold(u16 c)
  19 {
  20         u16 tmp;
  21
  22         tmp = hfsplus_case_fold_table[c >> 8];
  23         if (tmp)
  24                 tmp = hfsplus_case_fold_table[tmp + (c & 0xff)];
  25         else
  26                 tmp = c;
  27         return tmp;
  28 }
  29
  30 /* Compare unicode strings, return values like normal strcmp */
  31 int hfsplus_strcasecmp(const struct hfsplus_unistr *s1,
  32                        const struct hfsplus_unistr *s2)
  33 {
  34         u16 len1, len2, c1, c2;
  35         const hfsplus_unichr *p1, *p2;
  36
  37         len1 = be16_to_cpu(s1->length);
  38         len2 = be16_to_cpu(s2->length);
  39         p1 = s1->unicode;
  40         p2 = s2->unicode;
  41
  42         while (1) {
  43                 c1 = c2 = 0;
  44
  45                 while (len1 && !c1) {
  46                         c1 = case_fold(be16_to_cpu(*p1));
  47                         p1++;
  48                         len1--;
  49                 }
  50                 while (len2 && !c2) {
  51                         c2 = case_fold(be16_to_cpu(*p2));
  52                         p2++;
  53                         len2--;
  54                 }
  55
  56                 if (c1 != c2)
  57                         return (c1 < c2) ? -1 : 1;
  58                 if (!c1 && !c2)
  59                         return 0;
  60         }
  61 }
  62
  63 /* Compare names as a sequence of 16-bit unsigned integers */
  64 int hfsplus_strcmp(const struct hfsplus_unistr *s1,
  65                    const struct hfsplus_unistr *s2)
  66 {
  67         u16 len1, len2, c1, c2;
  68         const hfsplus_unichr *p1, *p2;
  69         int len;
  70
  71         len1 = be16_to_cpu(s1->length);
  72         len2 = be16_to_cpu(s2->length);
  73         p1 = s1->unicode;
  74         p2 = s2->unicode;
  75
  76         for (len = min(len1, len2); len > 0; len--) {
  77                 c1 = be16_to_cpu(*p1);
  78                 c2 = be16_to_cpu(*p2);
  79                 if (c1 != c2)
  80                         return c1 < c2 ? -1 : 1;
  81                 p1++;
  82                 p2++;
  83         }
  84
  85         return len1 < len2 ? -1 :
  86                len1 > len2 ? 1 : 0;
  87 }
  88
  89
  90 #define Hangul_SBase    0xac00
  91 #define Hangul_LBase    0x1100
  92 #define Hangul_VBase    0x1161
  93 #define Hangul_TBase    0x11a7
  94 #define Hangul_SCount   11172
  95 #define Hangul_LCount   19
  96 #define Hangul_VCount   21
  97 #define Hangul_TCount   28
  98 #define Hangul_NCount   (Hangul_VCount * Hangul_TCount)
  99
 100
 101 static u16 *hfsplus_compose_lookup(u16 *p, u16 cc)
 102 {
 103         int i, s, e;
 104
 105         s = 1;
 106         e = p[1];
 107         if (!e || cc < p[s * 2] || cc > p[e * 2])
 108                 return NULL;
 109         do {
 110                 i = (s + e) / 2;
 111                 if (cc > p[i * 2])
 112                         s = i + 1;
 113                 else if (cc < p[i * 2])
 114                         e = i - 1;
 115                 else
 116                         return hfsplus_compose_table + p[i * 2 + 1];
 117         } while (s <= e);
 118         return NULL;
 119 }
 120
 121 int hfsplus_uni2asc(struct super_block *sb,
 122                 const struct hfsplus_unistr *ustr,
 123                 char *astr, int *len_p)
 124 {
 125         const hfsplus_unichr *ip;
 126         struct nls_table *nls = HFSPLUS_SB(sb)->nls;
 127         u8 *op;
 128         u16 cc, c0, c1;
 129         u16 *ce1, *ce2;
 130         int i, len, ustrlen, res, compose;
 131
 132         op = astr;
 133         ip = ustr->unicode;
 134         ustrlen = be16_to_cpu(ustr->length);
 135         len = *len_p;
 136         ce1 = NULL;
 137         compose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 138
 139         while (ustrlen > 0) {
 140                 c0 = be16_to_cpu(*ip++);
 141                 ustrlen--;
 142                 /* search for single decomposed char */
 143                 if (likely(compose))
 144                         ce1 = hfsplus_compose_lookup(hfsplus_compose_table, c0);
 145                 if (ce1)
 146                         cc = ce1[0];
 147                 else
 148                         cc = 0;
 149                 if (cc) {
 150                         /* start of a possibly decomposed Hangul char */
 151                         if (cc != 0xffff)
 152                                 goto done;
 153                         if (!ustrlen)
 154                                 goto same;
 155                         c1 = be16_to_cpu(*ip) - Hangul_VBase;
 156                         if (c1 < Hangul_VCount) {
 157                                 /* compose the Hangul char */
 158                                 cc = (c0 - Hangul_LBase) * Hangul_VCount;
 159                                 cc = (cc + c1) * Hangul_TCount;
 160                                 cc += Hangul_SBase;
 161                                 ip++;
 162                                 ustrlen--;
 163                                 if (!ustrlen)
 164                                         goto done;
 165                                 c1 = be16_to_cpu(*ip) - Hangul_TBase;
 166                                 if (c1 > 0 && c1 < Hangul_TCount) {
 167                                         cc += c1;
 168                                         ip++;
 169                                         ustrlen--;
 170                                 }
 171                                 goto done;
 172                         }
 173                 }
 174                 while (1) {
 175                         /* main loop for common case of not composed chars */
 176                         if (!ustrlen)
 177                                 goto same;
 178                         c1 = be16_to_cpu(*ip);
 179                         if (likely(compose))
 180                                 ce1 = hfsplus_compose_lookup(
 181                                         hfsplus_compose_table, c1);
 182                         if (ce1)
 183                                 break;
 184                         switch (c0) {
 185                         case 0:
 186                                 c0 = 0x2400;
 187                                 break;
 188                         case '/':
 189                                 c0 = ':';
 190                                 break;
 191                         }
 192                         res = nls->uni2char(c0, op, len);
 193                         if (res < 0) {
 194                                 if (res == -ENAMETOOLONG)
 195                                         goto out;
 196                                 *op = '?';
 197                                 res = 1;
 198                         }
 199                         op += res;
 200                         len -= res;
 201                         c0 = c1;
 202                         ip++;
 203                         ustrlen--;
 204                 }
 205                 ce2 = hfsplus_compose_lookup(ce1, c0);
 206                 if (ce2) {
 207                         i = 1;
 208                         while (i < ustrlen) {
 209                                 ce1 = hfsplus_compose_lookup(ce2,
 210                                         be16_to_cpu(ip[i]));
 211                                 if (!ce1)
 212                                         break;
 213                                 i++;
 214                                 ce2 = ce1;
 215                         }
 216                         cc = ce2[0];
 217                         if (cc) {
 218                                 ip += i;
 219                                 ustrlen -= i;
 220                                 goto done;
 221                         }
 222                 }
 223 same:
 224                 switch (c0) {
 225                 case 0:
 226                         cc = 0x2400;
 227                         break;
 228                 case '/':
 229                         cc = ':';
 230                         break;
 231                 default:
 232                         cc = c0;
 233                 }
 234 done:
 235                 res = nls->uni2char(cc, op, len);
 236                 if (res < 0) {
 237                         if (res == -ENAMETOOLONG)
 238                                 goto out;
 239                         *op = '?';
 240                         res = 1;
 241                 }
 242                 op += res;
 243                 len -= res;
 244         }
 245         res = 0;
 246 out:
 247         *len_p = (char *)op - astr;
 248         return res;
 249 }
 250
 251 /*
 252  * Convert one or more ASCII characters into a single unicode character.
 253  * Returns the number of ASCII characters corresponding to the unicode char.
 254  */
 255 static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
 256                               wchar_t *uc)
 257 {
 258         int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc);
 259         if (size <= 0) {
 260                 *uc = '?';
 261                 size = 1;
 262         }
 263         switch (*uc) {
 264         case 0x2400:
 265                 *uc = 0;
 266                 break;
 267         case ':':
 268                 *uc = '/';
 269                 break;
 270         }
 271         return size;
 272 }
 273
 274 /* Decomposes a single unicode character. */
 275 static inline u16 *decompose_unichar(wchar_t uc, int *size)
 276 {
 277         int off;
 278
 279         off = hfsplus_decompose_table[(uc >> 12) & 0xf];
 280         if (off == 0 || off == 0xffff)
 281                 return NULL;
 282
 283         off = hfsplus_decompose_table[off + ((uc >> 8) & 0xf)];
 284         if (!off)
 285                 return NULL;
 286
 287         off = hfsplus_decompose_table[off + ((uc >> 4) & 0xf)];
 288         if (!off)
 289                 return NULL;
 290
 291         off = hfsplus_decompose_table[off + (uc & 0xf)];
 292         *size = off & 3;
 293         if (*size == 0)
 294                 return NULL;
 295         return hfsplus_decompose_table + (off / 4);
 296 }
 297
 298 int hfsplus_asc2uni(struct super_block *sb,
 299                     struct hfsplus_unistr *ustr, int max_unistr_len,
 300                     const char *astr, int len)
 301 {
 302         int size, dsize, decompose;
 303         u16 *dstr, outlen = 0;
 304         wchar_t c;
 305
 306         decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 307         while (outlen < max_unistr_len && len > 0) {
 308                 size = asc2unichar(sb, astr, len, &c);
 309
 310                 if (decompose)
 311                         dstr = decompose_unichar(c, &dsize);
 312                 else
 313                         dstr = NULL;
 314                 if (dstr) {
 315                         if (outlen + dsize > max_unistr_len)
 316                                 break;
 317                         do {
 318                                 ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
 319                         } while (--dsize > 0);
 320                 } else
 321                         ustr->unicode[outlen++] = cpu_to_be16(c);
 322
 323                 astr += size;
 324                 len -= size;
 325         }
 326         ustr->length = cpu_to_be16(outlen);
 327         if (len > 0)
 328                 return -ENAMETOOLONG;
 329         return 0;
 330 }
 331
 332 /*
 333  * Hash a string to an integer as appropriate for the HFS+ filesystem.
 334  * Composed unicode characters are decomposed and case-folding is performed
 335  * if the appropriate bits are (un)set on the superblock.
 336  */
 337 int hfsplus_hash_dentry(const struct dentry *dentry, struct qstr *str)
 338 {
 339         struct super_block *sb = dentry->d_sb;
 340         const char *astr;
 341         const u16 *dstr;
 342         int casefold, decompose, size, len;
 343         unsigned long hash;
 344         wchar_t c;
 345         u16 c2;
 346
 347         casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
 348         decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 349         hash = init_name_hash(dentry);
 350         astr = str->name;
 351         len = str->len;
 352         while (len > 0) {
 353                 int uninitialized_var(dsize);
 354                 size = asc2unichar(sb, astr, len, &c);
 355                 astr += size;
 356                 len -= size;
 357
 358                 if (decompose)
 359                         dstr = decompose_unichar(c, &dsize);
 360                 else
 361                         dstr = NULL;
 362                 if (dstr) {
 363                         do {
 364                                 c2 = *dstr++;
 365                                 if (casefold)
 366                                         c2 = case_fold(c2);
 367                                 if (!casefold || c2)
 368                                         hash = partial_name_hash(c2, hash);
 369                         } while (--dsize > 0);
 370                 } else {
 371                         c2 = c;
 372                         if (casefold)
 373                                 c2 = case_fold(c2);
 374                         if (!casefold || c2)
 375                                 hash = partial_name_hash(c2, hash);
 376                 }
 377         }
 378         str->hash = end_name_hash(hash);
 379
 380         return 0;
 381 }
 382
 383 /*
 384  * Compare strings with HFS+ filename ordering.
 385  * Composed unicode characters are decomposed and case-folding is performed
 386  * if the appropriate bits are (un)set on the superblock.
 387  */
 388 int hfsplus_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 389                 unsigned int len, const char *str, const struct qstr *name)
 390 {
 391         struct super_block *sb = parent->d_sb;
 392         int casefold, decompose, size;
 393         int dsize1, dsize2, len1, len2;
 394         const u16 *dstr1, *dstr2;
 395         const char *astr1, *astr2;
 396         u16 c1, c2;
 397         wchar_t c;
 398
 399         casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
 400         decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 401         astr1 = str;
 402         len1 = len;
 403         astr2 = name->name;
 404         len2 = name->len;
 405         dsize1 = dsize2 = 0;
 406         dstr1 = dstr2 = NULL;
 407
 408         while (len1 > 0 && len2 > 0) {
 409                 if (!dsize1) {
 410                         size = asc2unichar(sb, astr1, len1, &c);
 411                         astr1 += size;
 412                         len1 -= size;
 413
 414                         if (decompose)
 415                                 dstr1 = decompose_unichar(c, &dsize1);
 416                         if (!decompose || !dstr1) {
 417                                 c1 = c;
 418                                 dstr1 = &c1;
 419                                 dsize1 = 1;
 420                         }
 421                 }
 422
 423                 if (!dsize2) {
 424                         size = asc2unichar(sb, astr2, len2, &c);
 425                         astr2 += size;
 426                         len2 -= size;
 427
 428                         if (decompose)
 429                                 dstr2 = decompose_unichar(c, &dsize2);
 430                         if (!decompose || !dstr2) {
 431                                 c2 = c;
 432                                 dstr2 = &c2;
 433                                 dsize2 = 1;
 434                         }
 435                 }
 436
 437                 c1 = *dstr1;
 438                 c2 = *dstr2;
 439                 if (casefold) {
 440                         c1 = case_fold(c1);
 441                         if (!c1) {
 442                                 dstr1++;
 443                                 dsize1--;
 444                                 continue;
 445                         }
 446                         c2 = case_fold(c2);
 447                         if (!c2) {
 448                                 dstr2++;
 449                                 dsize2--;
 450                                 continue;
 451                         }
 452                 }
 453                 if (c1 < c2)
 454                         return -1;
 455                 else if (c1 > c2)
 456                         return 1;
 457
 458                 dstr1++;
 459                 dsize1--;
 460                 dstr2++;
 461                 dsize2--;
 462         }
 463
 464         if (len1 < len2)
 465                 return -1;
 466         if (len1 > len2)
 467                 return 1;
 468         return 0;
 469 }