linux/fs/hfsplus/unicode.c
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   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 */
  18static 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 */
  31int 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 */
  64int 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
 101static 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
 121int 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                }
 223same:
 224                switch (c0) {
 225                case 0:
 226                        cc = 0x2400;
 227                        break;
 228                case '/':
 229                        cc = ':';
 230                        break;
 231                default:
 232                        cc = c0;
 233                }
 234done:
 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;
 246out:
 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 */
 255static 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. */
 275static 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
 298int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
 299                    const char *astr, int len)
 300{
 301        int size, dsize, decompose;
 302        u16 *dstr, outlen = 0;
 303        wchar_t c;
 304
 305        decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 306        while (outlen < HFSPLUS_MAX_STRLEN && len > 0) {
 307                size = asc2unichar(sb, astr, len, &c);
 308
 309                if (decompose)
 310                        dstr = decompose_unichar(c, &dsize);
 311                else
 312                        dstr = NULL;
 313                if (dstr) {
 314                        if (outlen + dsize > HFSPLUS_MAX_STRLEN)
 315                                break;
 316                        do {
 317                                ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
 318                        } while (--dsize > 0);
 319                } else
 320                        ustr->unicode[outlen++] = cpu_to_be16(c);
 321
 322                astr += size;
 323                len -= size;
 324        }
 325        ustr->length = cpu_to_be16(outlen);
 326        if (len > 0)
 327                return -ENAMETOOLONG;
 328        return 0;
 329}
 330
 331/*
 332 * Hash a string to an integer as appropriate for the HFS+ filesystem.
 333 * Composed unicode characters are decomposed and case-folding is performed
 334 * if the appropriate bits are (un)set on the superblock.
 335 */
 336int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
 337                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();
 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 */
 388int hfsplus_compare_dentry(const struct dentry *parent,
 389                const struct inode *pinode,
 390                const struct dentry *dentry, const struct inode *inode,
 391                unsigned int len, const char *str, const struct qstr *name)
 392{
 393        struct super_block *sb = parent->d_sb;
 394        int casefold, decompose, size;
 395        int dsize1, dsize2, len1, len2;
 396        const u16 *dstr1, *dstr2;
 397        const char *astr1, *astr2;
 398        u16 c1, c2;
 399        wchar_t c;
 400
 401        casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
 402        decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
 403        astr1 = str;
 404        len1 = len;
 405        astr2 = name->name;
 406        len2 = name->len;
 407        dsize1 = dsize2 = 0;
 408        dstr1 = dstr2 = NULL;
 409
 410        while (len1 > 0 && len2 > 0) {
 411                if (!dsize1) {
 412                        size = asc2unichar(sb, astr1, len1, &c);
 413                        astr1 += size;
 414                        len1 -= size;
 415
 416                        if (decompose)
 417                                dstr1 = decompose_unichar(c, &dsize1);
 418                        if (!decompose || !dstr1) {
 419                                c1 = c;
 420                                dstr1 = &c1;
 421                                dsize1 = 1;
 422                        }
 423                }
 424
 425                if (!dsize2) {
 426                        size = asc2unichar(sb, astr2, len2, &c);
 427                        astr2 += size;
 428                        len2 -= size;
 429
 430                        if (decompose)
 431                                dstr2 = decompose_unichar(c, &dsize2);
 432                        if (!decompose || !dstr2) {
 433                                c2 = c;
 434                                dstr2 = &c2;
 435                                dsize2 = 1;
 436                        }
 437                }
 438
 439                c1 = *dstr1;
 440                c2 = *dstr2;
 441                if (casefold) {
 442                        c1 = case_fold(c1);
 443                        if (!c1) {
 444                                dstr1++;
 445                                dsize1--;
 446                                continue;
 447                        }
 448                        c2 = case_fold(c2);
 449                        if (!c2) {
 450                                dstr2++;
 451                                dsize2--;
 452                                continue;
 453                        }
 454                }
 455                if (c1 < c2)
 456                        return -1;
 457                else if (c1 > c2)
 458                        return 1;
 459
 460                dstr1++;
 461                dsize1--;
 462                dstr2++;
 463                dsize2--;
 464        }
 465
 466        if (len1 < len2)
 467                return -1;
 468        if (len1 > len2)
 469                return 1;
 470        return 0;
 471}
 472
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