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 = MAXUSHORT;
 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                 break;
 230             }
 231         }
 232         else if (Expression->Buffer[ExpressionPosition] == ANSI_DOS_STAR)
 233         {
 234             StarFound = MAXUSHORT;
 235             MatchingChars = NamePosition;
 236             while (MatchingChars < Name->Length)
 237             {
 238                 if (Name->Buffer[MatchingChars] == '.')
 239                 {
 240                     NamePosition = MatchingChars;
 241                 }
 242                 MatchingChars++;
 243             }
 244             ExpressionPosition++;
 245         }
 246         else if (StarFound != MAXUSHORT)
 247         {
 248             ExpressionPosition = StarFound + 1;
 249             while (Name->Buffer[NamePosition] != Expression->Buffer[ExpressionPosition] &&
 250                    NamePosition < Name->Length)
 251             {
 252                 NamePosition++;
 253             }
 254         }
 255         else
 256         {
 257             break;
 258         }
 259     }
 260     if (ExpressionPosition + 1 == Expression->Length && NamePosition == Name->Length &&
 261         Expression->Buffer[ExpressionPosition] == ANSI_DOS_DOT)
 262     {
 263         ExpressionPosition++;
 264     }
 265
 266     return (ExpressionPosition == Expression->Length && NamePosition == Name->Length);
 267 }
 268
 269 /*++
 270  * @name FsRtlIsFatDbcsLegal
 271  * @implemented
 272  *
 273  * Returns TRUE if the given DbcsName is a valid FAT filename (in 8.3)
 274  *
 275  * @param DbcsName
 276  *        The filename to check. It can also contains pathname.
 277  *
 278  * @param WildCardsPermissible
 279  *        If this is set to FALSE and if filename contains wildcard, the function
 280  *        will fail
 281  *
 282  * @param PathNamePermissible
 283  *        If this is set to FALSE and if the filename comes with a pathname, the
 284  *        function will fail
 285  *
 286  * @param LeadingBackslashPermissible
 287  *        If this is set to FALSE and if the filename starts with a backslash, the
 288  *        function will fail
 289  *
 290  * @return TRUE if the DbcsName is legal, FALSE otherwise
 291  *
 292  * @remarks None
 293  *
 294  *--*/
 295 BOOLEAN
 296 NTAPI
 297 FsRtlIsFatDbcsLegal(IN ANSI_STRING DbcsName,
 298                     IN BOOLEAN WildCardsPermissible,
 299                     IN BOOLEAN PathNamePermissible,
 300                     IN BOOLEAN LeadingBackslashPermissible)
 301 {
 302     ANSI_STRING FirstPart, RemainingPart, Name;
 303     BOOLEAN LastDot;
 304     USHORT i;
 305     PAGED_CODE();
 306
 307     /* Just quit if the string is empty */
 308     if (!DbcsName.Length)
 309         return FALSE;
 310
 311     /* DbcsName wasn't supposed to be started with \ */
 312     if (!LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 313         return FALSE;
 314     /* DbcsName was allowed to be started with \, but now, remove it */
 315     else if (LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 316     {
 317         DbcsName.Buffer = DbcsName.Buffer + 1;
 318         DbcsName.Length = DbcsName.Length - 1;
 319         DbcsName.MaximumLength = DbcsName.MaximumLength - 1;
 320     }
 321
 322     /* Extract first part of the DbcsName to work on */
 323     FsRtlDissectDbcs(DbcsName, &FirstPart, &RemainingPart);
 324     while (FirstPart.Length > 0)
 325     {
 326         /* Reset dots count */
 327         LastDot = FALSE;
 328
 329         /* Accept special filename if wildcards are allowed */
 330         if (WildCardsPermissible && (FirstPart.Length == 1 || FirstPart.Length == 2) && FirstPart.Buffer[0] == '.')
 331         {
 332             if (FirstPart.Length == 2)
 333             {
 334                 if (FirstPart.Buffer[1] == '.')
 335                 {
 336                     goto EndLoop;
 337                 }
 338             }
 339             else
 340             {
 341                 goto EndLoop;
 342             }
 343         }
 344
 345         /* Filename must be 8.3 filename */
 346         if (FirstPart.Length < 3 || FirstPart.Length > 12)
 347             return FALSE;
 348
 349         /* Now, we will parse the filename to find everything bad in */
 350         for (i = 0; i < FirstPart.Length; i++)
 351         {
 352             /* First make sure the character it's not the Lead DBCS */
 353             if (FsRtlIsLeadDbcsCharacter(FirstPart.Buffer[i]))
 354             {
 355                 if (i == (FirstPart.Length) - 1)
 356                     return FALSE;
 357                 i++;
 358             }
 359             /* Then check for bad characters */
 360             else if (!FsRtlIsAnsiCharacterLegalFat(FirstPart.Buffer[i], WildCardsPermissible))
 361             {
 362                 return FALSE;
 363             }
 364             else if (FirstPart.Buffer[i] == '.')
 365             {
 366                 /* Filename can only contain one dot */
 367                 if (LastDot)
 368                     return FALSE;
 369
 370                 LastDot = TRUE;
 371
 372                 /* We mustn't have spaces before dot or at the end of the filename
 373                  * and no dot at the beginning of the filename */
 374                 if ((i == (FirstPart.Length) - 1) || i == 0)
 375                     return FALSE;
 376
 377                 if (i > 0)
 378                     if (FirstPart.Buffer[i - 1] == ' ')
 379                         return FALSE;
 380
 381                 /* Filename must be 8.3 filename and not 3.8 filename */
 382                 if ((FirstPart.Length - 1) - i > 3)
 383                     return FALSE;
 384             }
 385         }
 386
 387         /* Filename mustn't finish with a space */
 388         if (FirstPart.Buffer[FirstPart.Length - 1] == ' ')
 389             return FALSE;
 390
 391         EndLoop:
 392         /* Preparing next loop */
 393         Name.Buffer = RemainingPart.Buffer;
 394         Name.Length = RemainingPart.Length;
 395         Name.MaximumLength = RemainingPart.MaximumLength;
 396
 397         /* Call once again our dissect function */
 398         FsRtlDissectDbcs(Name, &FirstPart, &RemainingPart);
 399
 400         /* We found a pathname, it wasn't allowed */
 401         if (FirstPart.Length > 0 && !PathNamePermissible)
 402             return FALSE;
 403     }
 404     return TRUE;
 405 }
 406
 407 /*++
 408  * @name FsRtlIsHpfsDbcsLegal
 409  * @implemented
 410  *
 411  * Returns TRUE if the given DbcsName is a valid HPFS filename
 412  *
 413  * @param DbcsName
 414  *        The filename to check. It can also contains pathname.
 415  *
 416  * @param WildCardsPermissible
 417  *        If this is set to FALSE and if filename contains wildcard, the function
 418  *        will fail
 419  *
 420  * @param PathNamePermissible
 421  *        If this is set to FALSE and if the filename comes with a pathname, the
 422  *        function will fail
 423  *
 424  * @param LeadingBackslashPermissible
 425  *        If this is set to FALSE and if the filename starts with a backslash, the
 426  *        function will fail
 427  *
 428  * @return TRUE if the DbcsName is legal, FALSE otherwise
 429  *
 430  * @remarks None
 431  *
 432  *--*/
 433 BOOLEAN
 434 NTAPI
 435 FsRtlIsHpfsDbcsLegal(IN ANSI_STRING DbcsName,
 436                      IN BOOLEAN WildCardsPermissible,
 437                      IN BOOLEAN PathNamePermissible,
 438                      IN BOOLEAN LeadingBackslashPermissible)
 439 {
 440     ANSI_STRING FirstPart, RemainingPart, Name;
 441     USHORT i;
 442     PAGED_CODE();
 443
 444     /* Just quit if the string is empty */
 445     if (!DbcsName.Length)
 446         return FALSE;
 447
 448     /* DbcsName wasn't supposed to be started with \ */
 449     if (!LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 450         return FALSE;
 451     /* DbcsName was allowed to be started with \, but now, remove it */
 452     else if (LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
 453     {
 454         DbcsName.Buffer = DbcsName.Buffer + 1;
 455         DbcsName.Length = DbcsName.Length - 1;
 456         DbcsName.MaximumLength = DbcsName.MaximumLength - 1;
 457     }
 458
 459     /* Extract first part of the DbcsName to work on */
 460     FsRtlDissectDbcs(DbcsName, &FirstPart, &RemainingPart);
 461     while (FirstPart.Length > 0)
 462     {
 463         /* Accept special filename if wildcards are allowed */
 464         if (WildCardsPermissible && (FirstPart.Length == 1 || FirstPart.Length == 2) && FirstPart.Buffer[0] == '.')
 465         {
 466             if (FirstPart.Length == 2)
 467             {
 468                 if (FirstPart.Buffer[1] == '.')
 469                 {
 470                     goto EndLoop;
 471                 }
 472             }
 473             else
 474             {
 475                 goto EndLoop;
 476             }
 477         }
 478
 479         /* Filename must be 255 bytes maximum */
 480         if (FirstPart.Length > 255)
 481             return FALSE;
 482
 483         /* Now, we will parse the filename to find everything bad in */
 484         for (i = 0; i < FirstPart.Length; i++)
 485         {
 486             /* First make sure the character it's not the Lead DBCS */
 487             if (FsRtlIsLeadDbcsCharacter(FirstPart.Buffer[i]))
 488             {
 489                 if (i == (FirstPart.Length) - 1)
 490                     return FALSE;
 491                 i++;
 492             }
 493             /* Then check for bad characters */
 494             else if (!FsRtlIsAnsiCharacterLegalHpfs(FirstPart.Buffer[i], WildCardsPermissible))
 495             {
 496                 return FALSE;
 497             }
 498         }
 499
 500         /* Filename mustn't finish with a space or a dot */
 501         if ((FirstPart.Buffer[FirstPart.Length - 1] == ' ') ||
 502             (FirstPart.Buffer[FirstPart.Length - 1] == '.'))
 503             return FALSE;
 504
 505         EndLoop:
 506         /* Preparing next loop */
 507         Name.Buffer = RemainingPart.Buffer;
 508         Name.Length = RemainingPart.Length;
 509         Name.MaximumLength = RemainingPart.MaximumLength;
 510
 511         /* Call once again our dissect function */
 512         FsRtlDissectDbcs(Name, &FirstPart, &RemainingPart);
 513
 514         /* We found a pathname, it wasn't allowed */
 515         if (FirstPart.Length > 0 && !PathNamePermissible)
 516             return FALSE;
 517     }
 518     return TRUE;
 519 }