fs/ntfs/unistr.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
   4  *
   5  * Copyright (c) 2001-2006 Anton Altaparmakov
   6  */
   7
   8 #include <linux/slab.h>
   9
  10 #include "types.h"
  11 #include "debug.h"
  12 #include "ntfs.h"
  13
  14 /*
  15  * IMPORTANT
  16  * =========
  17  *
  18  * All these routines assume that the Unicode characters are in little endian
  19  * encoding inside the strings!!!
  20  */
  21
  22 /*
  23  * This is used by the name collation functions to quickly determine what
  24  * characters are (in)valid.
  25  */
  26 static const u8 legal_ansi_char_array[0x40] = {
  27         0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  28         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  29
  30         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  31         0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
  32
  33         0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
  34         0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
  35
  36         0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
  37         0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
  38 };
  39
  40 /**
  41  * ntfs_are_names_equal - compare two Unicode names for equality
  42  * @s1:                 name to compare to @s2
  43  * @s1_len:             length in Unicode characters of @s1
  44  * @s2:                 name to compare to @s1
  45  * @s2_len:             length in Unicode characters of @s2
  46  * @ic:                 ignore case bool
  47  * @upcase:             upcase table (only if @ic == IGNORE_CASE)
  48  * @upcase_size:        length in Unicode characters of @upcase (if present)
  49  *
  50  * Compare the names @s1 and @s2 and return 'true' (1) if the names are
  51  * identical, or 'false' (0) if they are not identical. If @ic is IGNORE_CASE,
  52  * the @upcase table is used to performa a case insensitive comparison.
  53  */
  54 bool ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
  55                 const ntfschar *s2, size_t s2_len, const IGNORE_CASE_BOOL ic,
  56                 const ntfschar *upcase, const u32 upcase_size)
  57 {
  58         if (s1_len != s2_len)
  59                 return false;
  60         if (ic == CASE_SENSITIVE)
  61                 return !ntfs_ucsncmp(s1, s2, s1_len);
  62         return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
  63 }
  64
  65 /**
  66  * ntfs_collate_names - collate two Unicode names
  67  * @name1:      first Unicode name to compare
  68  * @name2:      second Unicode name to compare
  69  * @err_val:    if @name1 contains an invalid character return this value
  70  * @ic:         either CASE_SENSITIVE or IGNORE_CASE
  71  * @upcase:     upcase table (ignored if @ic is CASE_SENSITIVE)
  72  * @upcase_len: upcase table size (ignored if @ic is CASE_SENSITIVE)
  73  *
  74  * ntfs_collate_names collates two Unicode names and returns:
  75  *
  76  *  -1 if the first name collates before the second one,
  77  *   0 if the names match,
  78  *   1 if the second name collates before the first one, or
  79  * @err_val if an invalid character is found in @name1 during the comparison.
  80  *
  81  * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
  82  */
  83 int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
  84                 const ntfschar *name2, const u32 name2_len,
  85                 const int err_val, const IGNORE_CASE_BOOL ic,
  86                 const ntfschar *upcase, const u32 upcase_len)
  87 {
  88         u32 cnt, min_len;
  89         u16 c1, c2;
  90
  91         min_len = name1_len;
  92         if (name1_len > name2_len)
  93                 min_len = name2_len;
  94         for (cnt = 0; cnt < min_len; ++cnt) {
  95                 c1 = le16_to_cpu(*name1++);
  96                 c2 = le16_to_cpu(*name2++);
  97                 if (ic) {
  98                         if (c1 < upcase_len)
  99                                 c1 = le16_to_cpu(upcase[c1]);
 100                         if (c2 < upcase_len)
 101                                 c2 = le16_to_cpu(upcase[c2]);
 102                 }
 103                 if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 104                         return err_val;
 105                 if (c1 < c2)
 106                         return -1;
 107                 if (c1 > c2)
 108                         return 1;
 109         }
 110         if (name1_len < name2_len)
 111                 return -1;
 112         if (name1_len == name2_len)
 113                 return 0;
 114         /* name1_len > name2_len */
 115         c1 = le16_to_cpu(*name1);
 116         if (c1 < 64 && legal_ansi_char_array[c1] & 8)
 117                 return err_val;
 118         return 1;
 119 }
 120
 121 /**
 122  * ntfs_ucsncmp - compare two little endian Unicode strings
 123  * @s1:         first string
 124  * @s2:         second string
 125  * @n:          maximum unicode characters to compare
 126  *
 127  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 128  * The strings in little endian format and appropriate le16_to_cpu()
 129  * conversion is performed on non-little endian machines.
 130  *
 131  * The function returns an integer less than, equal to, or greater than zero
 132  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 133  * to be less than, to match, or be greater than @s2.
 134  */
 135 int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n)
 136 {
 137         u16 c1, c2;
 138         size_t i;
 139
 140         for (i = 0; i < n; ++i) {
 141                 c1 = le16_to_cpu(s1[i]);
 142                 c2 = le16_to_cpu(s2[i]);
 143                 if (c1 < c2)
 144                         return -1;
 145                 if (c1 > c2)
 146                         return 1;
 147                 if (!c1)
 148                         break;
 149         }
 150         return 0;
 151 }
 152
 153 /**
 154  * ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
 155  * @s1:                 first string
 156  * @s2:                 second string
 157  * @n:                  maximum unicode characters to compare
 158  * @upcase:             upcase table
 159  * @upcase_size:        upcase table size in Unicode characters
 160  *
 161  * Compare the first @n characters of the Unicode strings @s1 and @s2,
 162  * ignoring case. The strings in little endian format and appropriate
 163  * le16_to_cpu() conversion is performed on non-little endian machines.
 164  *
 165  * Each character is uppercased using the @upcase table before the comparison.
 166  *
 167  * The function returns an integer less than, equal to, or greater than zero
 168  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
 169  * to be less than, to match, or be greater than @s2.
 170  */
 171 int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
 172                 const ntfschar *upcase, const u32 upcase_size)
 173 {
 174         size_t i;
 175         u16 c1, c2;
 176
 177         for (i = 0; i < n; ++i) {
 178                 if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
 179                         c1 = le16_to_cpu(upcase[c1]);
 180                 if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
 181                         c2 = le16_to_cpu(upcase[c2]);
 182                 if (c1 < c2)
 183                         return -1;
 184                 if (c1 > c2)
 185                         return 1;
 186                 if (!c1)
 187                         break;
 188         }
 189         return 0;
 190 }
 191
 192 void ntfs_upcase_name(ntfschar *name, u32 name_len, const ntfschar *upcase,
 193                 const u32 upcase_len)
 194 {
 195         u32 i;
 196         u16 u;
 197
 198         for (i = 0; i < name_len; i++)
 199                 if ((u = le16_to_cpu(name[i])) < upcase_len)
 200                         name[i] = upcase[u];
 201 }
 202
 203 void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
 204                 const ntfschar *upcase, const u32 upcase_len)
 205 {
 206         ntfs_upcase_name((ntfschar*)&file_name_attr->file_name,
 207                         file_name_attr->file_name_length, upcase, upcase_len);
 208 }
 209
 210 int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
 211                 FILE_NAME_ATTR *file_name_attr2,
 212                 const int err_val, const IGNORE_CASE_BOOL ic,
 213                 const ntfschar *upcase, const u32 upcase_len)
 214 {
 215         return ntfs_collate_names((ntfschar*)&file_name_attr1->file_name,
 216                         file_name_attr1->file_name_length,
 217                         (ntfschar*)&file_name_attr2->file_name,
 218                         file_name_attr2->file_name_length,
 219                         err_val, ic, upcase, upcase_len);
 220 }
 221
 222 /**
 223  * ntfs_nlstoucs - convert NLS string to little endian Unicode string
 224  * @vol:        ntfs volume which we are working with
 225  * @ins:        input NLS string buffer
 226  * @ins_len:    length of input string in bytes
 227  * @outs:       on return contains the allocated output Unicode string buffer
 228  *
 229  * Convert the input string @ins, which is in whatever format the loaded NLS
 230  * map dictates, into a little endian, 2-byte Unicode string.
 231  *
 232  * This function allocates the string and the caller is responsible for
 233  * calling kmem_cache_free(ntfs_name_cache, *@outs); when finished with it.
 234  *
 235  * On success the function returns the number of Unicode characters written to
 236  * the output string *@outs (>= 0), not counting the terminating Unicode NULL
 237  * character. *@outs is set to the allocated output string buffer.
 238  *
 239  * On error, a negative number corresponding to the error code is returned. In
 240  * that case the output string is not allocated. Both *@outs and *@outs_len
 241  * are then undefined.
 242  *
 243  * This might look a bit odd due to fast path optimization...
 244  */
 245 int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
 246                 const int ins_len, ntfschar **outs)
 247 {
 248         struct nls_table *nls = vol->nls_map;
 249         ntfschar *ucs;
 250         wchar_t wc;
 251         int i, o, wc_len;
 252
 253         /* We do not trust outside sources. */
 254         if (likely(ins)) {
 255                 ucs = kmem_cache_alloc(ntfs_name_cache, GFP_NOFS);
 256                 if (likely(ucs)) {
 257                         for (i = o = 0; i < ins_len; i += wc_len) {
 258                                 wc_len = nls->char2uni(ins + i, ins_len - i,
 259                                                 &wc);
 260                                 if (likely(wc_len >= 0 &&
 261                                                 o < NTFS_MAX_NAME_LEN)) {
 262                                         if (likely(wc)) {
 263                                                 ucs[o++] = cpu_to_le16(wc);
 264                                                 continue;
 265                                         } /* else if (!wc) */
 266                                         break;
 267                                 } /* else if (wc_len < 0 ||
 268                                                 o >= NTFS_MAX_NAME_LEN) */
 269                                 goto name_err;
 270                         }
 271                         ucs[o] = 0;
 272                         *outs = ucs;
 273                         return o;
 274                 } /* else if (!ucs) */
 275                 ntfs_error(vol->sb, "Failed to allocate buffer for converted "
 276                                 "name from ntfs_name_cache.");
 277                 return -ENOMEM;
 278         } /* else if (!ins) */
 279         ntfs_error(vol->sb, "Received NULL pointer.");
 280         return -EINVAL;
 281 name_err:
 282         kmem_cache_free(ntfs_name_cache, ucs);
 283         if (wc_len < 0) {
 284                 ntfs_error(vol->sb, "Name using character set %s contains "
 285                                 "characters that cannot be converted to "
 286                                 "Unicode.", nls->charset);
 287                 i = -EILSEQ;
 288         } else /* if (o >= NTFS_MAX_NAME_LEN) */ {
 289                 ntfs_error(vol->sb, "Name is too long (maximum length for a "
 290                                 "name on NTFS is %d Unicode characters.",
 291                                 NTFS_MAX_NAME_LEN);
 292                 i = -ENAMETOOLONG;
 293         }
 294         return i;
 295 }
 296
 297 /**
 298  * ntfs_ucstonls - convert little endian Unicode string to NLS string
 299  * @vol:        ntfs volume which we are working with
 300  * @ins:        input Unicode string buffer
 301  * @ins_len:    length of input string in Unicode characters
 302  * @outs:       on return contains the (allocated) output NLS string buffer
 303  * @outs_len:   length of output string buffer in bytes
 304  *
 305  * Convert the input little endian, 2-byte Unicode string @ins, of length
 306  * @ins_len into the string format dictated by the loaded NLS.
 307  *
 308  * If *@outs is NULL, this function allocates the string and the caller is
 309  * responsible for calling kfree(*@outs); when finished with it. In this case
 310  * @outs_len is ignored and can be 0.
 311  *
 312  * On success the function returns the number of bytes written to the output
 313  * string *@outs (>= 0), not counting the terminating NULL byte. If the output
 314  * string buffer was allocated, *@outs is set to it.
 315  *
 316  * On error, a negative number corresponding to the error code is returned. In
 317  * that case the output string is not allocated. The contents of *@outs are
 318  * then undefined.
 319  *
 320  * This might look a bit odd due to fast path optimization...
 321  */
 322 int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
 323                 const int ins_len, unsigned char **outs, int outs_len)
 324 {
 325         struct nls_table *nls = vol->nls_map;
 326         unsigned char *ns;
 327         int i, o, ns_len, wc;
 328
 329         /* We don't trust outside sources. */
 330         if (ins) {
 331                 ns = *outs;
 332                 ns_len = outs_len;
 333                 if (ns && !ns_len) {
 334                         wc = -ENAMETOOLONG;
 335                         goto conversion_err;
 336                 }
 337                 if (!ns) {
 338                         ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
 339                         ns = kmalloc(ns_len + 1, GFP_NOFS);
 340                         if (!ns)
 341                                 goto mem_err_out;
 342                 }
 343                 for (i = o = 0; i < ins_len; i++) {
 344 retry:                  wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
 345                                         ns_len - o);
 346                         if (wc > 0) {
 347                                 o += wc;
 348                                 continue;
 349                         } else if (!wc)
 350                                 break;
 351                         else if (wc == -ENAMETOOLONG && ns != *outs) {
 352                                 unsigned char *tc;
 353                                 /* Grow in multiples of 64 bytes. */
 354                                 tc = kmalloc((ns_len + 64) &
 355                                                 ~63, GFP_NOFS);
 356                                 if (tc) {
 357                                         memcpy(tc, ns, ns_len);
 358                                         ns_len = ((ns_len + 64) & ~63) - 1;
 359                                         kfree(ns);
 360                                         ns = tc;
 361                                         goto retry;
 362                                 } /* No memory so goto conversion_error; */
 363                         } /* wc < 0, real error. */
 364                         goto conversion_err;
 365                 }
 366                 ns[o] = 0;
 367                 *outs = ns;
 368                 return o;
 369         } /* else (!ins) */
 370         ntfs_error(vol->sb, "Received NULL pointer.");
 371         return -EINVAL;
 372 conversion_err:
 373         ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
 374                         "converted to character set %s.  You might want to "
 375                         "try to use the mount option nls=utf8.", nls->charset);
 376         if (ns != *outs)
 377                 kfree(ns);
 378         if (wc != -ENAMETOOLONG)
 379                 wc = -EILSEQ;
 380         return wc;
 381 mem_err_out:
 382         ntfs_error(vol->sb, "Failed to allocate name!");
 383         return -ENOMEM;
 384 }