linux/fs/ntfs/unistr.c
<<
>>
Prefs
   1/*
   2 * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
   3 *
   4 * Copyright (c) 2001-2006 Anton Altaparmakov
   5 *
   6 * This program/include file is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License as published
   8 * by the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program/include file is distributed in the hope that it will be
  12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program (in the main directory of the Linux-NTFS
  18 * distribution in the file COPYING); if not, write to the Free Software
  19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22#include <linux/slab.h>
  23
  24#include "types.h"
  25#include "debug.h"
  26#include "ntfs.h"
  27
  28/*
  29 * IMPORTANT
  30 * =========
  31 *
  32 * All these routines assume that the Unicode characters are in little endian
  33 * encoding inside the strings!!!
  34 */
  35
  36/*
  37 * This is used by the name collation functions to quickly determine what
  38 * characters are (in)valid.
  39 */
  40static const u8 legal_ansi_char_array[0x40] = {
  41        0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  42        0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  43
  44        0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  45        0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  46
  47        0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
  48        0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
  49
  50        0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
  51        0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
  52};
  53
  54/**
  55 * ntfs_are_names_equal - compare two Unicode names for equality
  56 * @s1:                 name to compare to @s2
  57 * @s1_len:             length in Unicode characters of @s1
  58 * @s2:                 name to compare to @s1
  59 * @s2_len:             length in Unicode characters of @s2
  60 * @ic:                 ignore case bool
  61 * @upcase:             upcase table (only if @ic == IGNORE_CASE)
  62 * @upcase_size:        length in Unicode characters of @upcase (if present)
  63 *
  64 * Compare the names @s1 and @s2 and return 'true' (1) if the names are
  65 * identical, or 'false' (0) if they are not identical. If @ic is IGNORE_CASE,
  66 * the @upcase table is used to performa a case insensitive comparison.
  67 */
  68bool ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
  69                const ntfschar *s2, size_t s2_len, const IGNORE_CASE_BOOL ic,
  70                const ntfschar *upcase, const u32 upcase_size)
  71{
  72        if (s1_len != s2_len)
  73                return false;
  74        if (ic == CASE_SENSITIVE)
  75                return !ntfs_ucsncmp(s1, s2, s1_len);
  76        return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
  77}
  78
  79/**
  80 * ntfs_collate_names - collate two Unicode names
  81 * @name1:      first Unicode name to compare
  82 * @name2:      second Unicode name to compare
  83 * @err_val:    if @name1 contains an invalid character return this value
  84 * @ic:         either CASE_SENSITIVE or IGNORE_CASE
  85 * @upcase:     upcase table (ignored if @ic is CASE_SENSITIVE)
  86 * @upcase_len: upcase table size (ignored if @ic is CASE_SENSITIVE)
  87 *
  88 * ntfs_collate_names collates two Unicode names and returns:
  89 *
  90 *  -1 if the first name collates before the second one,
  91 *   0 if the names match,
  92 *   1 if the second name collates before the first one, or
  93 * @err_val if an invalid character is found in @name1 during the comparison.
  94 *
  95 * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
  96 */
  97int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
  98                const ntfschar *name2, const u32 name2_len,
  99                const int err_val, const IGNORE_CASE_BOOL ic,
 100                const ntfschar *upcase, const u32 upcase_len)
 101{
 102        u32 cnt, min_len;
 103        u16 c1, c2;
 104
 105        min_len = name1_len;
 106        if (name1_len > name2_len)
 107                min_len = name2_len;
 108        for (cnt = 0; cnt < min_len; ++cnt) {
 109                c1 = le16_to_cpu(*name1++);
 110                c2 = le16_to_cpu(*name2++);
 111                if (ic) {
 112                        if (c1 < upcase_len)
 113                                c1 = le16_to_cpu(upcase[c1]);
 114                        if (c2 < upcase_len)
 115                                c2 = le16_to_cpu(upcase[c2]);
 116                }
 117                if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 118                        return err_val;
 119                if (c1 < c2)
 120                        return -1;
 121                if (c1 > c2)
 122                        return 1;
 123        }
 124        if (name1_len < name2_len)
 125                return -1;
 126        if (name1_len == name2_len)
 127                return 0;
 128        /* name1_len > name2_len */
 129        c1 = le16_to_cpu(*name1);
 130        if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 131                return err_val;
 132        return 1;
 133}
 134
 135/**
 136 * ntfs_ucsncmp - compare two little endian Unicode strings
 137 * @s1:         first string
 138 * @s2:         second string
 139 * @n:          maximum unicode characters to compare
 140 *
 141 * Compare the first @n characters of the Unicode strings @s1 and @s2,
 142 * The strings in little endian format and appropriate le16_to_cpu()
 143 * conversion is performed on non-little endian machines.
 144 *
 145 * The function returns an integer less than, equal to, or greater than zero
 146 * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 147 * to be less than, to match, or be greater than @s2.
 148 */
 149int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n)
 150{
 151        u16 c1, c2;
 152        size_t i;
 153
 154        for (i = 0; i < n; ++i) {
 155                c1 = le16_to_cpu(s1[i]);
 156                c2 = le16_to_cpu(s2[i]);
 157                if (c1 < c2)
 158                        return -1;
 159                if (c1 > c2)
 160                        return 1;
 161                if (!c1)
 162                        break;
 163        }
 164        return 0;
 165}
 166
 167/**
 168 * ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
 169 * @s1:                 first string
 170 * @s2:                 second string
 171 * @n:                  maximum unicode characters to compare
 172 * @upcase:             upcase table
 173 * @upcase_size:        upcase table size in Unicode characters
 174 *
 175 * Compare the first @n characters of the Unicode strings @s1 and @s2,
 176 * ignoring case. The strings in little endian format and appropriate
 177 * le16_to_cpu() conversion is performed on non-little endian machines.
 178 *
 179 * Each character is uppercased using the @upcase table before the comparison.
 180 *
 181 * The function returns an integer less than, equal to, or greater than zero
 182 * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 183 * to be less than, to match, or be greater than @s2.
 184 */
 185int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
 186                const ntfschar *upcase, const u32 upcase_size)
 187{
 188        size_t i;
 189        u16 c1, c2;
 190
 191        for (i = 0; i < n; ++i) {
 192                if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
 193                        c1 = le16_to_cpu(upcase[c1]);
 194                if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
 195                        c2 = le16_to_cpu(upcase[c2]);
 196                if (c1 < c2)
 197                        return -1;
 198                if (c1 > c2)
 199                        return 1;
 200                if (!c1)
 201                        break;
 202        }
 203        return 0;
 204}
 205
 206void ntfs_upcase_name(ntfschar *name, u32 name_len, const ntfschar *upcase,
 207                const u32 upcase_len)
 208{
 209        u32 i;
 210        u16 u;
 211
 212        for (i = 0; i < name_len; i++)
 213                if ((u = le16_to_cpu(name[i])) < upcase_len)
 214                        name[i] = upcase[u];
 215}
 216
 217void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
 218                const ntfschar *upcase, const u32 upcase_len)
 219{
 220        ntfs_upcase_name((ntfschar*)&file_name_attr->file_name,
 221                        file_name_attr->file_name_length, upcase, upcase_len);
 222}
 223
 224int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
 225                FILE_NAME_ATTR *file_name_attr2,
 226                const int err_val, const IGNORE_CASE_BOOL ic,
 227                const ntfschar *upcase, const u32 upcase_len)
 228{
 229        return ntfs_collate_names((ntfschar*)&file_name_attr1->file_name,
 230                        file_name_attr1->file_name_length,
 231                        (ntfschar*)&file_name_attr2->file_name,
 232                        file_name_attr2->file_name_length,
 233                        err_val, ic, upcase, upcase_len);
 234}
 235
 236/**
 237 * ntfs_nlstoucs - convert NLS string to little endian Unicode string
 238 * @vol:        ntfs volume which we are working with
 239 * @ins:        input NLS string buffer
 240 * @ins_len:    length of input string in bytes
 241 * @outs:       on return contains the allocated output Unicode string buffer
 242 *
 243 * Convert the input string @ins, which is in whatever format the loaded NLS
 244 * map dictates, into a little endian, 2-byte Unicode string.
 245 *
 246 * This function allocates the string and the caller is responsible for
 247 * calling kmem_cache_free(ntfs_name_cache, *@outs); when finished with it.
 248 *
 249 * On success the function returns the number of Unicode characters written to
 250 * the output string *@outs (>= 0), not counting the terminating Unicode NULL
 251 * character. *@outs is set to the allocated output string buffer.
 252 *
 253 * On error, a negative number corresponding to the error code is returned. In
 254 * that case the output string is not allocated. Both *@outs and *@outs_len
 255 * are then undefined.
 256 *
 257 * This might look a bit odd due to fast path optimization...
 258 */
 259int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
 260                const int ins_len, ntfschar **outs)
 261{
 262        struct nls_table *nls = vol->nls_map;
 263        ntfschar *ucs;
 264        wchar_t wc;
 265        int i, o, wc_len;
 266
 267        /* We do not trust outside sources. */
 268        if (likely(ins)) {
 269                ucs = kmem_cache_alloc(ntfs_name_cache, GFP_NOFS);
 270                if (likely(ucs)) {
 271                        for (i = o = 0; i < ins_len; i += wc_len) {
 272                                wc_len = nls->char2uni(ins + i, ins_len - i,
 273                                                &wc);
 274                                if (likely(wc_len >= 0 &&
 275                                                o < NTFS_MAX_NAME_LEN)) {
 276                                        if (likely(wc)) {
 277                                                ucs[o++] = cpu_to_le16(wc);
 278                                                continue;
 279                                        } /* else if (!wc) */
 280                                        break;
 281                                } /* else if (wc_len < 0 ||
 282                                                o >= NTFS_MAX_NAME_LEN) */
 283                                goto name_err;
 284                        }
 285                        ucs[o] = 0;
 286                        *outs = ucs;
 287                        return o;
 288                } /* else if (!ucs) */
 289                ntfs_error(vol->sb, "Failed to allocate buffer for converted "
 290                                "name from ntfs_name_cache.");
 291                return -ENOMEM;
 292        } /* else if (!ins) */
 293        ntfs_error(vol->sb, "Received NULL pointer.");
 294        return -EINVAL;
 295name_err:
 296        kmem_cache_free(ntfs_name_cache, ucs);
 297        if (wc_len < 0) {
 298                ntfs_error(vol->sb, "Name using character set %s contains "
 299                                "characters that cannot be converted to "
 300                                "Unicode.", nls->charset);
 301                i = -EILSEQ;
 302        } else /* if (o >= NTFS_MAX_NAME_LEN) */ {
 303                ntfs_error(vol->sb, "Name is too long (maximum length for a "
 304                                "name on NTFS is %d Unicode characters.",
 305                                NTFS_MAX_NAME_LEN);
 306                i = -ENAMETOOLONG;
 307        }
 308        return i;
 309}
 310
 311/**
 312 * ntfs_ucstonls - convert little endian Unicode string to NLS string
 313 * @vol:        ntfs volume which we are working with
 314 * @ins:        input Unicode string buffer
 315 * @ins_len:    length of input string in Unicode characters
 316 * @outs:       on return contains the (allocated) output NLS string buffer
 317 * @outs_len:   length of output string buffer in bytes
 318 *
 319 * Convert the input little endian, 2-byte Unicode string @ins, of length
 320 * @ins_len into the string format dictated by the loaded NLS.
 321 *
 322 * If *@outs is NULL, this function allocates the string and the caller is
 323 * responsible for calling kfree(*@outs); when finished with it. In this case
 324 * @outs_len is ignored and can be 0.
 325 *
 326 * On success the function returns the number of bytes written to the output
 327 * string *@outs (>= 0), not counting the terminating NULL byte. If the output
 328 * string buffer was allocated, *@outs is set to it.
 329 *
 330 * On error, a negative number corresponding to the error code is returned. In
 331 * that case the output string is not allocated. The contents of *@outs are
 332 * then undefined.
 333 *
 334 * This might look a bit odd due to fast path optimization...
 335 */
 336int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
 337                const int ins_len, unsigned char **outs, int outs_len)
 338{
 339        struct nls_table *nls = vol->nls_map;
 340        unsigned char *ns;
 341        int i, o, ns_len, wc;
 342
 343        /* We don't trust outside sources. */
 344        if (ins) {
 345                ns = *outs;
 346                ns_len = outs_len;
 347                if (ns && !ns_len) {
 348                        wc = -ENAMETOOLONG;
 349                        goto conversion_err;
 350                }
 351                if (!ns) {
 352                        ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
 353                        ns = kmalloc(ns_len + 1, GFP_NOFS);
 354                        if (!ns)
 355                                goto mem_err_out;
 356                }
 357                for (i = o = 0; i < ins_len; i++) {
 358retry:                  wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
 359                                        ns_len - o);
 360                        if (wc > 0) {
 361                                o += wc;
 362                                continue;
 363                        } else if (!wc)
 364                                break;
 365                        else if (wc == -ENAMETOOLONG && ns != *outs) {
 366                                unsigned char *tc;
 367                                /* Grow in multiples of 64 bytes. */
 368                                tc = kmalloc((ns_len + 64) &
 369                                                ~63, GFP_NOFS);
 370                                if (tc) {
 371                                        memcpy(tc, ns, ns_len);
 372                                        ns_len = ((ns_len + 64) & ~63) - 1;
 373                                        kfree(ns);
 374                                        ns = tc;
 375                                        goto retry;
 376                                } /* No memory so goto conversion_error; */
 377                        } /* wc < 0, real error. */
 378                        goto conversion_err;
 379                }
 380                ns[o] = 0;
 381                *outs = ns;
 382                return o;
 383        } /* else (!ins) */
 384        ntfs_error(vol->sb, "Received NULL pointer.");
 385        return -EINVAL;
 386conversion_err:
 387        ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
 388                        "converted to character set %s.  You might want to "
 389                        "try to use the mount option nls=utf8.", nls->charset);
 390        if (ns != *outs)
 391                kfree(ns);
 392        if (wc != -ENAMETOOLONG)
 393                wc = -EILSEQ;
 394        return wc;
 395mem_err_out:
 396        ntfs_error(vol->sb, "Failed to allocate name!");
 397        return -ENOMEM;
 398}
 399
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.