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 && (cc = ce1[0])) {
 146                         /* start of a possibly decomposed Hangul char */
 147                         if (cc != 0xffff)
 148                                 goto done;
 149                         if (!ustrlen)
 150                                 goto same;
 151                         c1 = be16_to_cpu(*ip) - Hangul_VBase;
 152                         if (c1 < Hangul_VCount) {
 153                                 /* compose the Hangul char */
 154                                 cc = (c0 - Hangul_LBase) * Hangul_VCount;
 155                                 cc = (cc + c1) * Hangul_TCount;
 156                                 cc += Hangul_SBase;
 157                                 ip++;
 158                                 ustrlen--;
 159                                 if (!ustrlen)
 160                                         goto done;
 161                                 c1 = be16_to_cpu(*ip) - Hangul_TBase;
 162                                 if (c1 > 0 && c1 < Hangul_TCount) {
 163                                         cc += c1;
 164                                         ip++;
 165                                         ustrlen--;
 166                                 }
 167                                 goto done;
 168                         }
 169                 }
 170                 while (1) {
 171                         /* main loop for common case of not composed chars */
 172                         if (!ustrlen)
 173                                 goto same;
 174                         c1 = be16_to_cpu(*ip);
 175                         if (likely(compose))
 176                                 ce1 = hfsplus_compose_lookup(
 177                                         hfsplus_compose_table, c1);
 178                         if (ce1)
 179                                 break;
 180                         switch (c0) {
 181                         case 0:
 182                                 c0 = 0x2400;
 183                                 break;
 184                         case '/':
 185                                 c0 = ':';
 186                                 break;
 187                         }
 188                         res = nls->uni2char(c0, op, len);
 189                         if (res < 0) {
 190                                 if (res == -ENAMETOOLONG)
 191                                         goto out;
 192                                 *op = '?';
 193                                 res = 1;
 194                         }
 195                         op += res;
 196                         len -= res;
 197                         c0 = c1;
 198                         ip++;
 199                         ustrlen--;
 200                 }
 201                 ce2 = hfsplus_compose_lookup(ce1, c0);
 202                 if (ce2) {
 203                         i = 1;
 204                         while (i < ustrlen) {
 205                                 ce1 = hfsplus_compose_lookup(ce2,
 206                                         be16_to_cpu(ip[i]));
 207                                 if (!ce1)
 208                                         break;
 209                                 i++;
 210                                 ce2 = ce1;
 211                         }
 212                         if ((cc = ce2[0])) {
 213                                 ip += i;
 214                                 ustrlen -= i;
 215                                 goto done;
 216                         }
 217                 }
 218 same:
 219                 switch (c0) {
 220                 case 0:
 221                         cc = 0x2400;
 222                         break;
 223                 case '/':
 224                         cc = ':';
 225                         break;
 226                 default:
 227                         cc = c0;
 228                 }
 229 done:
 230                 res = nls->uni2char(cc, op, len);
 231                 if (res < 0) {
 232                         if (res == -ENAMETOOLONG)
 233                                 goto out;
 234                         *op = '?';
 235                         res = 1;
 236                 }
 237                 op += res;
 238                 len -= res;
 239         }
 240         res = 0;
 241 out:
 242         *len_p = (char *)op - astr;
 243         return res;
 244 }
 245
 246 /*
 247  * Convert one or more ASCII characters into a single unicode character.
 248  * Returns the number of ASCII characters corresponding to the unicode char.
 249  */
 250 static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
 251                               wchar_t *uc)
 252 {
 253         int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc);
 254         if (size <= 0) {
 255                 *uc = '?';
 256                 size = 1;
 257         }
 258         switch (*uc) {
 259         case 0x2400:
 260                 *uc = 0;
 261                 break;
 262         case ':':
 263                 *uc = '/';
 264                 break;
 265         }
 266         return size;
 267 }
 268
 269 /* Decomposes a single unicode character. */
 270 static inline u16 *decompose_unichar(wchar_t uc, int *size)
 271 {
 272         int off;
 273
 274         off = hfsplus_decompose_table[(uc >> 12) & 0xf];
 275         if (off == 0 || off == 0xffff)
 276                 return NULL;
 277
 278         off = hfsplus_decompose_table[off + ((uc >> 8) & 0xf)];
 279         if (!off)
 280                 return NULL;
 281
 282         off = hfsplus_decompose_table[off + ((uc >> 4) & 0xf)];
 283         if (!off)
 284                 return NULL;
 285
 286         off = hfsplus_decompose_table[off + (uc & 0xf)];
 287         *size = off & 3;
 288         if (*size == 0)
 289                 return NULL;
 290         return hfsplus_decompose_table + (off / 4);
 291 }
 292
 293 int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
 294                     const char *astr, int len)
 295 {
 296         int size, dsize, decompose;
 297         u16 *dstr, outlen = 0;
 298         wchar_t c;
 299
 300         decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 301         while (outlen < HFSPLUS_MAX_STRLEN && len > 0) {
 302                 size = asc2unichar(sb, astr, len, &c);
 303
 304                 if (decompose && (dstr = decompose_unichar(c, &dsize))) {
 305                         if (outlen + dsize > HFSPLUS_MAX_STRLEN)
 306                                 break;
 307                         do {
 308                                 ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
 309                         } while (--dsize > 0);
 310                 } else
 311                         ustr->unicode[outlen++] = cpu_to_be16(c);
 312
 313                 astr += size;
 314                 len -= size;
 315         }
 316         ustr->length = cpu_to_be16(outlen);
 317         if (len > 0)
 318                 return -ENAMETOOLONG;
 319         return 0;
 320 }
 321
 322 /*
 323  * Hash a string to an integer as appropriate for the HFS+ filesystem.
 324  * Composed unicode characters are decomposed and case-folding is performed
 325  * if the appropriate bits are (un)set on the superblock.
 326  */
 327 int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
 328                 struct qstr *str)
 329 {
 330         struct super_block *sb = dentry->d_sb;
 331         const char *astr;
 332         const u16 *dstr;
 333         int casefold, decompose, size, len;
 334         unsigned long hash;
 335         wchar_t c;
 336         u16 c2;
 337
 338         casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
 339         decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 340         hash = init_name_hash();
 341         astr = str->name;
 342         len = str->len;
 343         while (len > 0) {
 344                 int uninitialized_var(dsize);
 345                 size = asc2unichar(sb, astr, len, &c);
 346                 astr += size;
 347                 len -= size;
 348
 349                 if (decompose && (dstr = decompose_unichar(c, &dsize))) {
 350                         do {
 351                                 c2 = *dstr++;
 352                                 if (!casefold || (c2 = case_fold(c2)))
 353                                         hash = partial_name_hash(c2, hash);
 354                         } while (--dsize > 0);
 355                 } else {
 356                         c2 = c;
 357                         if (!casefold || (c2 = case_fold(c2)))
 358                                 hash = partial_name_hash(c2, hash);
 359                 }
 360         }
 361         str->hash = end_name_hash(hash);
 362
 363         return 0;
 364 }
 365
 366 /*
 367  * Compare strings with HFS+ filename ordering.
 368  * Composed unicode characters are decomposed and case-folding is performed
 369  * if the appropriate bits are (un)set on the superblock.
 370  */
 371 int hfsplus_compare_dentry(const struct dentry *parent,
 372                 const struct inode *pinode,
 373                 const struct dentry *dentry, const struct inode *inode,
 374                 unsigned int len, const char *str, const struct qstr *name)
 375 {
 376         struct super_block *sb = parent->d_sb;
 377         int casefold, decompose, size;
 378         int dsize1, dsize2, len1, len2;
 379         const u16 *dstr1, *dstr2;
 380         const char *astr1, *astr2;
 381         u16 c1, c2;
 382         wchar_t c;
 383
 384         casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
 385         decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 386         astr1 = str;
 387         len1 = len;
 388         astr2 = name->name;
 389         len2 = name->len;
 390         dsize1 = dsize2 = 0;
 391         dstr1 = dstr2 = NULL;
 392
 393         while (len1 > 0 && len2 > 0) {
 394                 if (!dsize1) {
 395                         size = asc2unichar(sb, astr1, len1, &c);
 396                         astr1 += size;
 397                         len1 -= size;
 398
 399                         if (decompose)
 400                                 dstr1 = decompose_unichar(c, &dsize1);
 401                         if (!decompose || !dstr1) {
 402                                 c1 = c;
 403                                 dstr1 = &c1;
 404                                 dsize1 = 1;
 405                         }
 406                 }
 407
 408                 if (!dsize2) {
 409                         size = asc2unichar(sb, astr2, len2, &c);
 410                         astr2 += size;
 411                         len2 -= size;
 412
 413                         if (decompose)
 414                                 dstr2 = decompose_unichar(c, &dsize2);
 415                         if (!decompose || !dstr2) {
 416                                 c2 = c;
 417                                 dstr2 = &c2;
 418                                 dsize2 = 1;
 419                         }
 420                 }
 421
 422                 c1 = *dstr1;
 423                 c2 = *dstr2;
 424                 if (casefold) {
 425                         if  (!(c1 = case_fold(c1))) {
 426                                 dstr1++;
 427                                 dsize1--;
 428                                 continue;
 429                         }
 430                         if (!(c2 = case_fold(c2))) {
 431                                 dstr2++;
 432                                 dsize2--;
 433                                 continue;
 434                         }
 435                 }
 436                 if (c1 < c2)
 437                         return -1;
 438                 else if (c1 > c2)
 439                         return 1;
 440
 441                 dstr1++;
 442                 dsize1--;
 443                 dstr2++;
 444                 dsize2--;
 445         }
 446
 447         if (len1 < len2)
 448                 return -1;
 449         if (len1 > len2)
 450                 return 1;
 451         return 0;
 452 }