reactos/ntoskrnl/fsrtl/dbcsname.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         GPL - See COPYING in the top level directory
   4  * FILE:            ntoskrnl/fsrtl/name.c
   5  * PURPOSE:         Provides DBCS parsing and other support routines for FSDs
   6  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7  *                  Pierre Schweitzer (pierre.schweitzer@reactos.org)
   8  */
   9
  10 /* INCLUDES ******************************************************************/
  11
  12 #include <ntoskrnl.h>
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16 /* PUBLIC FUNCTIONS **********************************************************/
  17
  18 /*++
  19  * @name FsRtlDissectDbcs
  20  * @implemented
  21  *
  22  * Dissects a given path name into first and remaining part.
  23  *
  24  * @param Name
  25  *        ANSI string to dissect.
  26  *
  27  * @param FirstPart
  28  *        Pointer to user supplied ANSI_STRING, that will later point
  29  *        to the first part of the original name.
  30  *
  31  * @param RemainingPart
  32  *        Pointer to user supplied ANSI_STRING, that will later point
  33  *        to the remaining part of the original name.
  34  *
  35  * @return None
  36  *
  37  * @remarks Example:
  38  *          Name:           \test1\test2\test3
  39  *          FirstPart:      test1
  40  *          RemainingPart:  test2\test3
  41  *
  42  *--*/
  43 VOID
  44 NTAPI
  45 FsRtlDissectDbcs(IN ANSI_STRING Name,
  46                  OUT PANSI_STRING FirstPart,
  47                  OUT PANSI_STRING RemainingPart)
  48 {
  49     USHORT FirstPosition, i;
  50     USHORT SkipFirstSlash = 0;
  51     PAGED_CODE();
  52
  53     /* Zero the strings before continuing */
  54     RtlZeroMemory(FirstPart, sizeof(ANSI_STRING));
  55     RtlZeroMemory(RemainingPart, sizeof(ANSI_STRING));
  56
  57     /* Just quit if the string is empty */
  58     if (!Name.Length) return;
  59
  60     /* Find first backslash */
  61     FirstPosition = Name.Length;
  62     for (i = 0; i < Name.Length; i++)
  63     {
  64         /* First make sure the character it's not the Lead DBCS */
  65         if (FsRtlIsLeadDbcsCharacter(Name.Buffer[i]))
  66         {
  67             i++;
  68         }
  69         /* If we found one... */
  70         else if (Name.Buffer[i] == '\\')
  71         {
  72             /* If it begins string, just notice it and continue */
  73             if (i == 0)
  74             {
  75                 SkipFirstSlash = 1;
  76             }
  77             else
  78             {
  79                 /* Else, save its position and break out of the loop */
  80                 FirstPosition = i;
  81                 break;
  82             }
  83         }
  84     }
  85
  86     /* Set up the first result string */
  87     FirstPart->Buffer = Name.Buffer + SkipFirstSlash;
  88     FirstPart->Length = (FirstPosition - SkipFirstSlash);
  89     FirstPart->MaximumLength = FirstPart->Length;
  90
  91     /* And second one, if necessary */
  92     if (FirstPosition < (Name.Length))
  93     {
  94         RemainingPart->Buffer = Name.Buffer + FirstPosition + 1;
  95         RemainingPart->Length = Name.Length - (FirstPosition + 1);
  96         RemainingPart->MaximumLength = RemainingPart->Length;
  97     }
  98 }
  99
 100 /*++
 101  * @name FsRtlDoesDbcsContainWildCards
 102  * @implemented
 103  *
 104  * Returns TRUE if the given DbcsName contains wildcards such as *, ?,
 105  * ANSI_DOS_STAR, ANSI_DOS_DOT, and ANSI_DOS_QM
 106  *
 107  * @param Name
 108  *        The Name to check
 109  *
 110  * @return TRUE if there are wildcards, FALSE otherwise
 111  *
 112  * @remarks None
 113  *
 114  *--*/
 115 BOOLEAN
 116 NTAPI
 117 FsRtlDoesDbcsContainWildCards(IN PANSI_STRING Name)
 118 {
 119     USHORT i;
 120     PAGED_CODE();
 121
 122     /* Check every character */
 123     for (i = 0; i < Name->Length; i++)
 124     {
 125         /* First make sure it's not the Lead DBCS */
 126         if (FsRtlIsLeadDbcsCharacter(Name->Buffer[i]))
 127         {
 128             i++;
 129         }
 130         else if (FsRtlIsAnsiCharacterWild(Name->Buffer[i]))
 131         {
 132             /* Now return if it has a wildcard */
 133             return TRUE;
 134         }
 135     }
 136
 137     /* We didn't return above...so none found */
 138     return FALSE;
 139 }
 140
 141 /*++
 142  * @name FsRtlIsDbcsInExpression
 143  * @implemented
 144  *
 145  * Check if the Name string is in the Expression string.
 146  *
 147  * @param Expression
 148  *        The string in which we've to find Name. It can contains wildcards
 149  *
 150  * @param Name
 151  *        The string to find. It cannot contain wildcards.
 152  *
 153  * @return TRUE if Name is found in Expression, FALSE otherwise
 154  *
 155  * @remarks
 156  *
 157  *--*/
 158 BOOLEAN
 159 NTAPI
 160 FsRtlIsDbcsInExpression(IN PANSI_STRING Expression,
 161                         IN PANSI_STRING Name)
 162 {
 163     USHORT ExpressionPosition = 0, NamePosition = 0, MatchingChars, StarFound = MAXUSHORT;
 164     PAGED_CODE();
 165
 166     ASSERT(Name->Length);
 167     ASSERT(Expression->Length);
 168     ASSERT(!FsRtlDoesDbcsContainWildCards(Name));
 169
 170     while (NamePosition < Name->Length && ExpressionPosition < Expression->Length)
 171     {
 172         if ((Expression->Buffer[ExpressionPosition] == Name->Buffer[NamePosition]))
 173         {
 174             NamePosition++;
 175             ExpressionPosition++;
 176         }
 177         else if (StarFound != MAXUSHORT && (Expression->Buffer[StarFound + 1] == '*' ||
 178                  Expression->Buffer[StarFound + 1] == '?' || Expression->Buffer[StarFound + 1] == ANSI_DOS_DOT))
 179         {
 180             ExpressionPosition = StarFound + 1;
 181             switch (Expression->Buffer[ExpressionPosition])
 182             {
 183                 case '*':
 184                     StarFound = ExpressionPosition++;
 185                     break;
 186
 187                 case '?':
 188                     ExpressionPosition++;
 189                     MatchingChars = NamePosition;
 190                     while (Name->Buffer[NamePosition] != Expression->Buffer[ExpressionPosition] &&
 191                            NamePosition < Name->Length)
 192                     {
 193                         NamePosition++;
 194                     }
 195
 196                     if (NamePosition - MatchingChars > 0)
 197                     {
 198                         StarFound = MAXUSHORT;
 199                     }
 200                     break;
 201
 202                 case ANSI_DOS_DOT:
 203                     while (Name->Buffer[NamePosition] != '.' && NamePosition < Name->Length)
 204                     {
 205                         NamePosition++;
 206                     }
 207                     ExpressionPosition++;
 208                     StarFound = MAXUSHORT;
 209                     break;
 210
 211                 default:
 212                     /* Should never happen */
 213                     ASSERT(FALSE);
 214             }
 215         }
 216         else if ((Expression->Buffer[ExpressionPosition] == '?') || (Expression->Buffer[ExpressionPosition] == ANSI_DOS_QM) ||
 217                  (Expression->Buffer[ExpressionPosition] == ANSI_DOS_DOT && Name->Buffer[NamePosition] == '.'))
 218         {
 219             NamePosition++;
 220             ExpressionPosition++;
 221             StarFound = MAXUSHORT;
 222         }
 223         else if (Expression->Buffer[ExpressionPosition] == '*')
 224         {
 225             StarFound = ExpressionPosition++;
 226             if (ExpressionPosition == Expression->Length)
 227             {
 228                 NamePosition = Name->Length;
 229             }
 230         }
 231         else if (Expression->Buffer[ExpressionPosition] == ANSI_DOS_STAR)
 232         {
 233             StarFound = MAXUSHORT;
 234             MatchingChars = NamePosition;
 235             while (MatchingChars < Name->Length)
 236             {
 237                 if (Name->Buffer[MatchingChars] == '.')
 238                 {
 239                     NamePosition = MatchingChars;
 240                 }
 241                 MatchingChars++;
 242             }
 243             ExpressionPosition++;
 244         }
 245         else if (StarFound != MAXUSHORT)
 246         {
 247             ExpressionPosition = StarFound + 1;
 248             while (Name->Buffer[NamePosition] != Expression->Buffer[ExpressionPosition] &&
 249                    NamePosition < Name->Length)
 250             {
 251                 NamePosition++;
 252             }
 253         }
 254         else
 255         {
 256             NamePosition = Name->Length;
 257         }
 258     }
 259     if (ExpressionPosition + 1 == Expression->Length && NamePosition == Name->Length &&
 260         Expression->Buffer[ExpressionPosition] == ANSI_DOS_DOT)
 261     {
 262         ExpressionPosition++;
 263     }
 264
 265     return (ExpressionPosition == Expression->Length && NamePosition == Name->Length);
 266 }
 267
 268 /*++
 269  * @name FsRtlIsFatDbcsLegal
 270  * @implemented
 271  *
 272  * Returns TRUE if the given DbcsName is a valid FAT filename (in 8.3)
 273  *
 274  * @param DbcsName
 275  *        The filename to check. It can also contains pathname.
 276  *
 277  * @param WildCardsPermissible
 278  *        If this is set to FALSE and if filename contains wildcard, the function
 279  *        will fail
 280  *
 281  * @param PathNamePermissible
 282  *        If this is set to FALSE and if the filename comes with a pathname, the
 283  *        function will fail
 284  *
 285  * @param LeadingBackslashPermissible
 286  *        If this is set to FALSE and if the filename starts with a backslash, the
 287  *        function will fail
 288  *
 289  * @return TRUE if the DbcsName is legal, FALSE otherwise
 290  *
 291  * @remarks None
 292  *
 293  *--*/
 294 BOOLEAN
 295 NTAPI
 296 FsRtlIsFatDbcsLegal(IN ANSI_STRING DbcsName,
 297                     IN BOOLEAN WildCardsPermissible,
 298                     IN BOOLEAN PathNamePermissible,
 299                     IN BOOLEAN LeadingBackslashPermissible)
 300 {
 301     ANSI_STRING FirstPart, RemainingPart, Name;
 302     BOOLEAN LastDot;
 303     USHORT i;
 304     PAGED_CODE();
 305
 306     /* Just quit if the string is empty */
 307     if (!DbcsName.Length)
 308         return FALSE;
 309
 310     /* DbcsName wasn't supposed to be started with \ */
 311     if (!LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 312         return FALSE;
 313     /* DbcsName was allowed to be started with \, but now, remove it */
 314     else if (LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 315     {
 316         DbcsName.Buffer = DbcsName.Buffer + 1;
 317         DbcsName.Length = DbcsName.Length - 1;
 318         DbcsName.MaximumLength = DbcsName.MaximumLength - 1;
 319     }
 320
 321     /* Extract first part of the DbcsName to work on */
 322     FsRtlDissectDbcs(DbcsName, &FirstPart, &RemainingPart);
 323     while (FirstPart.Length > 0)
 324     {
 325         /* Reset dots count */
 326         LastDot = FALSE;
 327
 328         /* Accept special filename if wildcards are allowed */
 329         if (WildCardsPermissible && (FirstPart.Length == 1 || FirstPart.Length == 2) && FirstPart.Buffer[0] == '.')
 330         {
 331             if (FirstPart.Length == 2)
 332             {
 333                 if (FirstPart.Buffer[1] == '.')
 334                 {
 335                     goto EndLoop;
 336                 }
 337             }
 338             else
 339             {
 340                 goto EndLoop;
 341             }
 342         }
 343
 344         /* Filename must be 8.3 filename */
 345         if (FirstPart.Length < 3 || FirstPart.Length > 12)
 346             return FALSE;
 347
 348         /* Now, we will parse the filename to find everything bad in */
 349         for (i = 0; i < FirstPart.Length; i++)
 350         {
 351             /* First make sure the character it's not the Lead DBCS */
 352             if (FsRtlIsLeadDbcsCharacter(FirstPart.Buffer[i]))
 353             {
 354                 if (i == (FirstPart.Length) - 1)
 355                     return FALSE;
 356                 i++;
 357             }
 358             /* Then check for bad characters */
 359             else if (!FsRtlIsAnsiCharacterLegalFat(FirstPart.Buffer[i], WildCardsPermissible))
 360             {
 361                 return FALSE;
 362             }
 363             else if (FirstPart.Buffer[i] == '.')
 364             {
 365                 /* Filename can only contain one dot */
 366                 if (LastDot)
 367                     return FALSE;
 368
 369                 LastDot = TRUE;
 370
 371                 /* We mustn't have spaces before dot or at the end of the filename
 372                  * and no dot at the beginning of the filename */
 373                 if ((i == (FirstPart.Length) - 1) || i == 0)
 374                     return FALSE;
 375
 376                 if (i > 0)
 377                     if (FirstPart.Buffer[i - 1] == ' ')
 378                         return FALSE;
 379
 380                 /* Filename must be 8.3 filename and not 3.8 filename */
 381                 if ((FirstPart.Length - 1) - i > 3)
 382                     return FALSE;
 383             }
 384         }
 385
 386         /* Filename mustn't finish with a space */
 387         if (FirstPart.Buffer[FirstPart.Length - 1] == ' ')
 388             return FALSE;
 389
 390         EndLoop:
 391         /* Preparing next loop */
 392         Name.Buffer = RemainingPart.Buffer;
 393         Name.Length = RemainingPart.Length;
 394         Name.MaximumLength = RemainingPart.MaximumLength;
 395
 396         /* Call once again our dissect function */
 397         FsRtlDissectDbcs(Name, &FirstPart, &RemainingPart);
 398
 399         /* We found a pathname, it wasn't allowed */
 400         if (FirstPart.Length > 0 && !PathNamePermissible)
 401             return FALSE;
 402     }
 403     return TRUE;
 404 }
 405
 406 /*++
 407  * @name FsRtlIsHpfsDbcsLegal
 408  * @implemented
 409  *
 410  * Returns TRUE if the given DbcsName is a valid HPFS filename
 411  *
 412  * @param DbcsName
 413  *        The filename to check. It can also contains pathname.
 414  *
 415  * @param WildCardsPermissible
 416  *        If this is set to FALSE and if filename contains wildcard, the function
 417  *        will fail
 418  *
 419  * @param PathNamePermissible
 420  *        If this is set to FALSE and if the filename comes with a pathname, the
 421  *        function will fail
 422  *
 423  * @param LeadingBackslashPermissible
 424  *        If this is set to FALSE and if the filename starts with a backslash, the
 425  *        function will fail
 426  *
 427  * @return TRUE if the DbcsName is legal, FALSE otherwise
 428  *
 429  * @remarks None
 430  *
 431  *--*/
 432 BOOLEAN
 433 NTAPI
 434 FsRtlIsHpfsDbcsLegal(IN ANSI_STRING DbcsName,
 435                      IN BOOLEAN WildCardsPermissible,
 436                      IN BOOLEAN PathNamePermissible,
 437                      IN BOOLEAN LeadingBackslashPermissible)
 438 {
 439     ANSI_STRING FirstPart, RemainingPart, Name;
 440     USHORT i;
 441     PAGED_CODE();
 442
 443     /* Just quit if the string is empty */
 444     if (!DbcsName.Length)
 445         return FALSE;
 446
 447     /* DbcsName wasn't supposed to be started with \ */
 448     if (!LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 449         return FALSE;
 450     /* DbcsName was allowed to be started with \, but now, remove it */
 451     else if (LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 452     {
 453         DbcsName.Buffer = DbcsName.Buffer + 1;
 454         DbcsName.Length = DbcsName.Length - 1;
 455         DbcsName.MaximumLength = DbcsName.MaximumLength - 1;
 456     }
 457
 458     /* Extract first part of the DbcsName to work on */
 459     FsRtlDissectDbcs(DbcsName, &FirstPart, &RemainingPart);
 460     while (FirstPart.Length > 0)
 461     {
 462         /* Accept special filename if wildcards are allowed */
 463         if (WildCardsPermissible && (FirstPart.Length == 1 || FirstPart.Length == 2) && FirstPart.Buffer[0] == '.')
 464         {
 465             if (FirstPart.Length == 2)
 466             {
 467                 if (FirstPart.Buffer[1] == '.')
 468                 {
 469                     goto EndLoop;
 470                 }
 471             }
 472             else
 473             {
 474                 goto EndLoop;
 475             }
 476         }
 477
 478         /* Filename must be 255 bytes maximum */
 479         if (FirstPart.Length > 255)
 480             return FALSE;
 481
 482         /* Now, we will parse the filename to find everything bad in */
 483         for (i = 0; i < FirstPart.Length; i++)
 484         {
 485             /* First make sure the character it's not the Lead DBCS */
 486             if (FsRtlIsLeadDbcsCharacter(FirstPart.Buffer[i]))
 487             {
 488                 if (i == (FirstPart.Length) - 1)
 489                     return FALSE;
 490                 i++;
 491             }
 492             /* Then check for bad characters */
 493             else if (!FsRtlIsAnsiCharacterLegalHpfs(FirstPart.Buffer[i], WildCardsPermissible))
 494             {
 495                 return FALSE;
 496             }
 497         }
 498
 499         /* Filename mustn't finish with a space or a dot */
 500         if ((FirstPart.Buffer[FirstPart.Length - 1] == ' ') ||
 501             (FirstPart.Buffer[FirstPart.Length - 1] == '.'))
 502             return FALSE;
 503
 504         EndLoop:
 505         /* Preparing next loop */
 506         Name.Buffer = RemainingPart.Buffer;
 507         Name.Length = RemainingPart.Length;
 508         Name.MaximumLength = RemainingPart.MaximumLength;
 509
 510         /* Call once again our dissect function */
 511         FsRtlDissectDbcs(Name, &FirstPart, &RemainingPart);
 512
 513         /* We found a pathname, it wasn't allowed */
 514         if (FirstPart.Length > 0 && !PathNamePermissible)
 515             return FALSE;
 516     }
 517     return TRUE;
 518 }