reactos/ntoskrnl/fsrtl/dbcsname.c
Amine Khaldi 527f2f9057 [SHELL/EXPERIMENTS]
* Create a branch for some evul shell experiments.

svn path=/branches/shell-experiments/; revision=61927
2014-02-02 19:37:27 +00:00

651 lines
20 KiB
C

/*
* PROJECT: ReactOS Kernel
* LICENSE: GPL - See COPYING in the top level directory
* FILE: ntoskrnl/fsrtl/name.c
* PURPOSE: Provides DBCS parsing and other support routines for FSDs
* PROGRAMMERS: Alex Ionescu (alex.ionescu@reactos.org)
* Pierre Schweitzer (pierre.schweitzer@reactos.org)
*/
/* INCLUDES ******************************************************************/
#include <ntoskrnl.h>
#define NDEBUG
#include <debug.h>
/* PUBLIC FUNCTIONS **********************************************************/
/*++
* @name FsRtlDissectDbcs
* @implemented
*
* Dissects a given path name into first and remaining part.
*
* @param Name
* ANSI string to dissect.
*
* @param FirstPart
* Pointer to user supplied ANSI_STRING, that will later point
* to the first part of the original name.
*
* @param RemainingPart
* Pointer to user supplied ANSI_STRING, that will later point
* to the remaining part of the original name.
*
* @return None
*
* @remarks Example:
* Name: \test1\test2\test3
* FirstPart: test1
* RemainingPart: test2\test3
*
*--*/
VOID
NTAPI
FsRtlDissectDbcs(IN ANSI_STRING Name,
OUT PANSI_STRING FirstPart,
OUT PANSI_STRING RemainingPart)
{
USHORT FirstPosition, i;
USHORT SkipFirstSlash = 0;
PAGED_CODE();
/* Zero the strings before continuing */
RtlZeroMemory(FirstPart, sizeof(ANSI_STRING));
RtlZeroMemory(RemainingPart, sizeof(ANSI_STRING));
/* Just quit if the string is empty */
if (!Name.Length) return;
/* Find first backslash */
FirstPosition = Name.Length;
for (i = 0; i < Name.Length; i++)
{
/* First make sure the character it's not the Lead DBCS */
if (FsRtlIsLeadDbcsCharacter(Name.Buffer[i]))
{
i++;
}
/* If we found one... */
else if (Name.Buffer[i] == '\\')
{
/* If it begins string, just notice it and continue */
if (i == 0)
{
SkipFirstSlash = 1;
}
else
{
/* Else, save its position and break out of the loop */
FirstPosition = i;
break;
}
}
}
/* Set up the first result string */
FirstPart->Buffer = Name.Buffer + SkipFirstSlash;
FirstPart->Length = (FirstPosition - SkipFirstSlash);
FirstPart->MaximumLength = FirstPart->Length;
/* And second one, if necessary */
if (FirstPosition < (Name.Length))
{
RemainingPart->Buffer = Name.Buffer + FirstPosition + 1;
RemainingPart->Length = Name.Length - (FirstPosition + 1);
RemainingPart->MaximumLength = RemainingPart->Length;
}
}
/*++
* @name FsRtlDoesDbcsContainWildCards
* @implemented
*
* Returns TRUE if the given DbcsName contains wildcards such as *, ?,
* ANSI_DOS_STAR, ANSI_DOS_DOT, and ANSI_DOS_QM
*
* @param Name
* The Name to check
*
* @return TRUE if there are wildcards, FALSE otherwise
*
* @remarks None
*
*--*/
BOOLEAN
NTAPI
FsRtlDoesDbcsContainWildCards(IN PANSI_STRING Name)
{
USHORT i;
PAGED_CODE();
/* Check every character */
for (i = 0; i < Name->Length; i++)
{
/* First make sure it's not the Lead DBCS */
if (FsRtlIsLeadDbcsCharacter(Name->Buffer[i]))
{
i++;
}
else if (FsRtlIsAnsiCharacterWild(Name->Buffer[i]))
{
/* Now return if it has a wildcard */
return TRUE;
}
}
/* We didn't return above...so none found */
return FALSE;
}
/*++
* @name FsRtlIsDbcsInExpression
* @implemented
*
* Check if the Name string is in the Expression string.
*
* @param Expression
* The string in which we've to find Name. It can contains wildcards
*
* @param Name
* The string to find. It cannot contain wildcards.
*
* @return TRUE if Name is found in Expression, FALSE otherwise
*
* @remarks
*
*--*/
BOOLEAN
NTAPI
FsRtlIsDbcsInExpression(IN PANSI_STRING Expression,
IN PANSI_STRING Name)
{
SHORT StarFound = -1, DosStarFound = -1;
PUSHORT BackTracking = NULL, DosBackTracking = NULL;
USHORT ExpressionPosition = 0, NamePosition = 0, MatchingChars, LastDot;
PAGED_CODE();
ASSERT(Name->Length);
ASSERT(Expression->Length);
ASSERT(!FsRtlDoesDbcsContainWildCards(Name));
/* Check if we were given strings at all */
if (!Name->Length || !Expression->Length)
{
/* Return TRUE if both strings are empty, otherwise FALSE */
if (Name->Length == 0 && Expression->Length == 0)
return TRUE;
else
return FALSE;
}
/* Check for a shortcut: just one wildcard */
if (Expression->Length == sizeof(CHAR))
{
if (Expression->Buffer[0] == '*')
return TRUE;
}
//ASSERT(FsRtlDoesDbcsContainWildCards(Expression));
/* Another shortcut, wildcard followed by some string */
if (Expression->Buffer[0] == '*')
{
/* Copy Expression to our local variable */
ANSI_STRING IntExpression = *Expression;
/* Skip the first char */
IntExpression.Buffer++;
IntExpression.Length -= sizeof(CHAR);
/* Continue only if the rest of the expression does NOT contain
any more wildcards */
if (!FsRtlDoesDbcsContainWildCards(&IntExpression))
{
/* Check for a degenerate case */
if (Name->Length < (Expression->Length - sizeof(CHAR)))
return FALSE;
/* Calculate position */
NamePosition = (Name->Length - IntExpression.Length) / sizeof(CHAR);
/* Check whether we are breaking a two chars char (DBCS) */
if (NlsMbOemCodePageTag)
{
MatchingChars = 0;
while (MatchingChars < NamePosition)
{
/* Check if current char is DBCS lead char, if so, jump by two chars */
MatchingChars += FsRtlIsLeadDbcsCharacter(Name->Buffer[MatchingChars]) ? 2 : 1;
}
/* If so, deny */
if (MatchingChars > NamePosition)
return FALSE;
}
/* Compare */
return RtlEqualMemory(IntExpression.Buffer,
(Name->Buffer + NamePosition),
IntExpression.Length);
}
}
while (NamePosition < Name->Length && ExpressionPosition < Expression->Length)
{
/* Basic check to test if chars are equal */
if ((Expression->Buffer[ExpressionPosition] == Name->Buffer[NamePosition]))
{
NamePosition++;
ExpressionPosition++;
}
/* Check cases that eat one char */
else if (Expression->Buffer[ExpressionPosition] == '?')
{
NamePosition++;
ExpressionPosition++;
}
/* Test star */
else if (Expression->Buffer[ExpressionPosition] == '*')
{
/* Skip contigous stars */
while (ExpressionPosition + 1 < Expression->Length && Expression->Buffer[ExpressionPosition + 1] == '*')
{
ExpressionPosition++;
}
/* Save star position */
if (!BackTracking)
{
BackTracking = ExAllocatePoolWithTag(PagedPool | POOL_RAISE_IF_ALLOCATION_FAILURE,
Expression->Length * sizeof(USHORT), 'nrSF');
}
BackTracking[++StarFound] = ExpressionPosition++;
/* If star is at the end, then eat all rest and leave */
if (ExpressionPosition == Expression->Length)
{
NamePosition = Name->Length;
break;
}
/* Allow null matching */
else if (Expression->Buffer[ExpressionPosition] != '?' &&
Expression->Buffer[ExpressionPosition] != Name->Buffer[NamePosition])
{
NamePosition++;
}
}
/* Check DOS_STAR */
else if (Expression->Buffer[ExpressionPosition] == ANSI_DOS_STAR)
{
/* Skip contigous stars */
while (ExpressionPosition + 1 < Expression->Length && Expression->Buffer[ExpressionPosition + 1] == ANSI_DOS_STAR)
{
ExpressionPosition++;
}
/* Look for last dot */
MatchingChars = 0;
LastDot = (USHORT)-1;
while (MatchingChars < Name->Length)
{
if (Name->Buffer[MatchingChars] == '.')
{
LastDot = MatchingChars;
if (LastDot > NamePosition)
break;
}
MatchingChars++;
}
/* If we don't have dots or we didn't find last yet
* start eating everything
*/
if (MatchingChars != Name->Length || LastDot == (USHORT)-1)
{
if (!DosBackTracking) DosBackTracking = ExAllocatePoolWithTag(PagedPool | POOL_RAISE_IF_ALLOCATION_FAILURE,
Expression->Length * sizeof(USHORT), 'nrSF');
DosBackTracking[++DosStarFound] = ExpressionPosition++;
/* Not the same char, start exploring */
if (Expression->Buffer[ExpressionPosition] != Name->Buffer[NamePosition])
NamePosition++;
}
else
{
/* Else, if we are at last dot, eat it - otherwise, null match */
if (Name->Buffer[NamePosition] == '.')
NamePosition++;
ExpressionPosition++;
}
}
/* Check DOS_DOT */
else if (Expression->Buffer[ExpressionPosition] == ANSI_DOS_DOT)
{
/* We only match dots */
if (Name->Buffer[NamePosition] == '.')
{
NamePosition++;
}
/* Try to explore later on for null matching */
else if (ExpressionPosition + 1 < Expression->Length &&
Name->Buffer[NamePosition] == Expression->Buffer[ExpressionPosition + 1])
{
NamePosition++;
}
ExpressionPosition++;
}
/* Check DOS_QM */
else if (Expression->Buffer[ExpressionPosition] == ANSI_DOS_QM)
{
/* We match everything except dots */
if (Name->Buffer[NamePosition] != '.')
{
NamePosition++;
}
ExpressionPosition++;
}
/* If nothing match, try to backtrack */
else if (StarFound >= 0)
{
ExpressionPosition = BackTracking[StarFound--];
}
else if (DosStarFound >= 0)
{
ExpressionPosition = DosBackTracking[DosStarFound--];
}
/* Otherwise, fail */
else
{
break;
}
/* Under certain circumstances, expression is over, but name isn't
* and we can backtrack, then, backtrack */
if (ExpressionPosition == Expression->Length &&
NamePosition != Name->Length && StarFound >= 0)
{
ExpressionPosition = BackTracking[StarFound--];
}
}
/* If we have nullable matching wc at the end of the string, eat them */
if (ExpressionPosition != Expression->Length && NamePosition == Name->Length)
{
while (ExpressionPosition < Expression->Length)
{
if (Expression->Buffer[ExpressionPosition] != ANSI_DOS_DOT &&
Expression->Buffer[ExpressionPosition] != '*' &&
Expression->Buffer[ExpressionPosition] != ANSI_DOS_STAR)
{
break;
}
ExpressionPosition++;
}
}
if (BackTracking)
{
ExFreePoolWithTag(BackTracking, 'nrSF');
}
if (DosBackTracking)
{
ExFreePoolWithTag(DosBackTracking, 'nrSF');
}
return (ExpressionPosition == Expression->Length && NamePosition == Name->Length);
}
/*++
* @name FsRtlIsFatDbcsLegal
* @implemented
*
* Returns TRUE if the given DbcsName is a valid FAT filename (in 8.3)
*
* @param DbcsName
* The filename to check. It can also contains pathname.
*
* @param WildCardsPermissible
* If this is set to FALSE and if filename contains wildcard, the function
* will fail
*
* @param PathNamePermissible
* If this is set to FALSE and if the filename comes with a pathname, the
* function will fail
*
* @param LeadingBackslashPermissible
* If this is set to FALSE and if the filename starts with a backslash, the
* function will fail
*
* @return TRUE if the DbcsName is legal, FALSE otherwise
*
* @remarks None
*
*--*/
BOOLEAN
NTAPI
FsRtlIsFatDbcsLegal(IN ANSI_STRING DbcsName,
IN BOOLEAN WildCardsPermissible,
IN BOOLEAN PathNamePermissible,
IN BOOLEAN LeadingBackslashPermissible)
{
ANSI_STRING FirstPart, RemainingPart, Name;
BOOLEAN LastDot;
USHORT i;
PAGED_CODE();
/* Just quit if the string is empty */
if (!DbcsName.Length)
return FALSE;
/* DbcsName wasn't supposed to be started with \ */
if (!LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
return FALSE;
/* DbcsName was allowed to be started with \, but now, remove it */
else if (LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
{
DbcsName.Buffer = DbcsName.Buffer + 1;
DbcsName.Length = DbcsName.Length - 1;
DbcsName.MaximumLength = DbcsName.MaximumLength - 1;
}
/* Extract first part of the DbcsName to work on */
FsRtlDissectDbcs(DbcsName, &FirstPart, &RemainingPart);
while (FirstPart.Length > 0)
{
/* Reset dots count */
LastDot = FALSE;
/* Accept special filename if wildcards are allowed */
if (WildCardsPermissible && (FirstPart.Length == 1 || FirstPart.Length == 2) && FirstPart.Buffer[0] == '.')
{
if (FirstPart.Length == 2)
{
if (FirstPart.Buffer[1] == '.')
{
goto EndLoop;
}
}
else
{
goto EndLoop;
}
}
/* Filename must be 8.3 filename */
if (FirstPart.Length < 3 || FirstPart.Length > 12)
return FALSE;
/* Now, we will parse the filename to find everything bad in */
for (i = 0; i < FirstPart.Length; i++)
{
/* First make sure the character it's not the Lead DBCS */
if (FsRtlIsLeadDbcsCharacter(FirstPart.Buffer[i]))
{
if (i == (FirstPart.Length) - 1)
return FALSE;
i++;
}
/* Then check for bad characters */
else if (!FsRtlIsAnsiCharacterLegalFat(FirstPart.Buffer[i], WildCardsPermissible))
{
return FALSE;
}
else if (FirstPart.Buffer[i] == '.')
{
/* Filename can only contain one dot */
if (LastDot)
return FALSE;
LastDot = TRUE;
/* We mustn't have spaces before dot or at the end of the filename
* and no dot at the beginning of the filename */
if ((i == (FirstPart.Length) - 1) || i == 0)
return FALSE;
if (i > 0)
if (FirstPart.Buffer[i - 1] == ' ')
return FALSE;
/* Filename must be 8.3 filename and not 3.8 filename */
if ((FirstPart.Length - 1) - i > 3)
return FALSE;
}
}
/* Filename mustn't finish with a space */
if (FirstPart.Buffer[FirstPart.Length - 1] == ' ')
return FALSE;
EndLoop:
/* Preparing next loop */
Name.Buffer = RemainingPart.Buffer;
Name.Length = RemainingPart.Length;
Name.MaximumLength = RemainingPart.MaximumLength;
/* Call once again our dissect function */
FsRtlDissectDbcs(Name, &FirstPart, &RemainingPart);
/* We found a pathname, it wasn't allowed */
if (FirstPart.Length > 0 && !PathNamePermissible)
return FALSE;
}
return TRUE;
}
/*++
* @name FsRtlIsHpfsDbcsLegal
* @implemented
*
* Returns TRUE if the given DbcsName is a valid HPFS filename
*
* @param DbcsName
* The filename to check. It can also contains pathname.
*
* @param WildCardsPermissible
* If this is set to FALSE and if filename contains wildcard, the function
* will fail
*
* @param PathNamePermissible
* If this is set to FALSE and if the filename comes with a pathname, the
* function will fail
*
* @param LeadingBackslashPermissible
* If this is set to FALSE and if the filename starts with a backslash, the
* function will fail
*
* @return TRUE if the DbcsName is legal, FALSE otherwise
*
* @remarks None
*
*--*/
BOOLEAN
NTAPI
FsRtlIsHpfsDbcsLegal(IN ANSI_STRING DbcsName,
IN BOOLEAN WildCardsPermissible,
IN BOOLEAN PathNamePermissible,
IN BOOLEAN LeadingBackslashPermissible)
{
ANSI_STRING FirstPart, RemainingPart, Name;
USHORT i;
PAGED_CODE();
/* Just quit if the string is empty */
if (!DbcsName.Length)
return FALSE;
/* DbcsName wasn't supposed to be started with \ */
if (!LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
return FALSE;
/* DbcsName was allowed to be started with \, but now, remove it */
else if (LeadingBackslashPermissible && DbcsName.Buffer[0] == '\\')
{
DbcsName.Buffer = DbcsName.Buffer + 1;
DbcsName.Length = DbcsName.Length - 1;
DbcsName.MaximumLength = DbcsName.MaximumLength - 1;
}
/* Extract first part of the DbcsName to work on */
FsRtlDissectDbcs(DbcsName, &FirstPart, &RemainingPart);
while (FirstPart.Length > 0)
{
/* Accept special filename if wildcards are allowed */
if (WildCardsPermissible && (FirstPart.Length == 1 || FirstPart.Length == 2) && FirstPart.Buffer[0] == '.')
{
if (FirstPart.Length == 2)
{
if (FirstPart.Buffer[1] == '.')
{
goto EndLoop;
}
}
else
{
goto EndLoop;
}
}
/* Filename must be 255 bytes maximum */
if (FirstPart.Length > 255)
return FALSE;
/* Now, we will parse the filename to find everything bad in */
for (i = 0; i < FirstPart.Length; i++)
{
/* First make sure the character it's not the Lead DBCS */
if (FsRtlIsLeadDbcsCharacter(FirstPart.Buffer[i]))
{
if (i == (FirstPart.Length) - 1)
return FALSE;
i++;
}
/* Then check for bad characters */
else if (!FsRtlIsAnsiCharacterLegalHpfs(FirstPart.Buffer[i], WildCardsPermissible))
{
return FALSE;
}
}
/* Filename mustn't finish with a space or a dot */
if ((FirstPart.Buffer[FirstPart.Length - 1] == ' ') ||
(FirstPart.Buffer[FirstPart.Length - 1] == '.'))
return FALSE;
EndLoop:
/* Preparing next loop */
Name.Buffer = RemainingPart.Buffer;
Name.Length = RemainingPart.Length;
Name.MaximumLength = RemainingPart.MaximumLength;
/* Call once again our dissect function */
FsRtlDissectDbcs(Name, &FirstPart, &RemainingPart);
/* We found a pathname, it wasn't allowed */
if (FirstPart.Length > 0 && !PathNamePermissible)
return FALSE;
}
return TRUE;
}