1072 lines
28 KiB
C
1072 lines
28 KiB
C
/*++
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Copyright (c) 1989 Microsoft Corporation
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Module Name:
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Name.c
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Abstract:
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The unicode name support package is for manipulating unicode strings
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The routines allow the caller to dissect and compare strings.
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This package uses the same FSRTL_COMPARISON_RESULT typedef used by name.c
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The following routines are provided by this package:
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o FsRtlDissectName - This routine takes a path name string and breaks
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into two parts. The first name in the string and the remainder.
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It also checks that the first name is valid for an NT file.
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o FsRtlColateNames - This routine is used to colate directories
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according to lexical ordering. Lexical ordering is strict unicode
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numerical oerdering.
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o FsRtlDoesNameContainsWildCards - This routine tells the caller if
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a string contains any wildcard characters.
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o FsRtlIsNameInExpression - This routine is used to compare a string
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against a template (possibly containing wildcards) to sees if the
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string is in the language denoted by the template.
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Author:
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Gary Kimura [GaryKi] 5-Feb-1990
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Revision History:
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--*/
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#include "FsRtlP.h"
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//
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// Trace level for the module
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//
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#define Dbg (0x10000000)
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//
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// Some special debugging stuff
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//
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#if DBG
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extern ULONG DaveDebug;
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#define DavePrint if (DaveDebug) DbgPrint
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#else
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#define DavePrint NOTHING
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#endif
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//
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// Define a tag for general pool allocations from this module
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//
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#undef MODULE_POOL_TAG
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#define MODULE_POOL_TAG ('nrSF')
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//
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// Local support routine prototypes
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//
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BOOLEAN
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FsRtlIsNameInExpressionPrivate (
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IN PUNICODE_STRING Expression,
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IN PUNICODE_STRING Name,
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IN BOOLEAN IgnoreCase,
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IN PWCH UpcaseTable
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);
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, FsRtlAreNamesEqual)
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#pragma alloc_text(PAGE, FsRtlDissectName)
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#pragma alloc_text(PAGE, FsRtlDoesNameContainWildCards)
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#pragma alloc_text(PAGE, FsRtlIsNameInExpression)
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#pragma alloc_text(PAGE, FsRtlIsNameInExpressionPrivate)
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#endif
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VOID
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FsRtlDissectName (
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IN UNICODE_STRING Path,
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OUT PUNICODE_STRING FirstName,
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OUT PUNICODE_STRING RemainingName
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)
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/*++
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Routine Description:
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This routine cracks a path. It picks off the first element in the
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given path name and provides both it and the remaining part. A path
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is a set of file names separated by backslashes. If a name begins
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with a backslash, the FirstName is the string immediately following
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the backslash. Here are some examples:
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Path FirstName RemainingName
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---- --------- -------------
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empty empty empty
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\ empty empty
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A A empty
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\A A empty
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A\B\C\D\E A B\C\D\E
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*A? *A? empty
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Note that both output strings use the same string buffer memory of the
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input string, and are not necessarily null terminated.
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Also, this routine makes no judgement as to the legality of each
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file name componant. This must be done separatly when each file name
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is extracted.
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Arguments:
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Path - The full path name to crack.
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FirstName - The first name in the path. Don't allocate a buffer for
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this string.
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RemainingName - The rest of the path. Don't allocate a buffer for this
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string.
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Return Value:
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None.
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--*/
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{
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ULONG i = 0;
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ULONG PathLength;
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ULONG FirstNameStart;
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PAGED_CODE();
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//
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// Make both output strings empty for now
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//
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FirstName->Length = 0;
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FirstName->MaximumLength = 0;
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FirstName->Buffer = NULL;
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RemainingName->Length = 0;
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RemainingName->MaximumLength = 0;
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RemainingName->Buffer = NULL;
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PathLength = Path.Length / sizeof(WCHAR);
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//
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// Check for an empty input string
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//
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if (PathLength == 0) {
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return;
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}
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//
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// Skip over a starting backslash, and make sure there is more.
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//
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if ( Path.Buffer[0] == L'\\' ) {
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i = 1;
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}
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//
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// Now run down the input string until we hit a backslash or the end
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// of the string, remembering where we started;
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//
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for ( FirstNameStart = i;
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(i < PathLength) && (Path.Buffer[i] != L'\\');
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i += 1 ) {
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NOTHING;
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}
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//
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// At this point all characters up to (but not including) i are
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// in the first part. So setup the first name
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//
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FirstName->Length = (USHORT)((i - FirstNameStart) * sizeof(WCHAR));
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FirstName->MaximumLength = FirstName->Length;
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FirstName->Buffer = &Path.Buffer[FirstNameStart];
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//
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// Now the remaining part needs a string only if the first part didn't
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// exhaust the entire input string. We know that if anything is left
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// that is must start with a backslash. Note that if there is only
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// a trailing backslash, the length will get correctly set to zero.
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//
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if (i < PathLength) {
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RemainingName->Length = (USHORT)((PathLength - (i + 1)) * sizeof(WCHAR));
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RemainingName->MaximumLength = RemainingName->Length;
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RemainingName->Buffer = &Path.Buffer[i + 1];
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}
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//
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// And return to our caller
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//
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return;
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}
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BOOLEAN
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FsRtlDoesNameContainWildCards (
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IN PUNICODE_STRING Name
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)
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/*++
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Routine Description:
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This routine simply scans the input Name string looking for any Nt
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wild card characters.
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Arguments:
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Name - The string to check.
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Return Value:
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BOOLEAN - TRUE if one or more wild card characters was found.
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--*/
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{
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PUSHORT p;
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PAGED_CODE();
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//
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// Check each character in the name to see if it's a wildcard
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// character.
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//
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if( Name->Length ) {
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for( p = Name->Buffer + (Name->Length / sizeof(WCHAR)) - 1;
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p >= Name->Buffer && *p != L'\\' ;
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p-- ) {
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//
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// check for a wild card character
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//
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if (FsRtlIsUnicodeCharacterWild( *p )) {
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//
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// Tell caller that this name contains wild cards
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//
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return TRUE;
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}
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}
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}
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//
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// No wildcard characters were found, so return to our caller
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//
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return FALSE;
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}
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BOOLEAN
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FsRtlAreNamesEqual (
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PCUNICODE_STRING ConstantNameA,
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PCUNICODE_STRING ConstantNameB,
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IN BOOLEAN IgnoreCase,
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IN PCWCH UpcaseTable OPTIONAL
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)
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/*++
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Routine Description:
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This routine simple returns whether the two names are exactly equal.
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If the two names are known to be constant, this routine is much
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faster than FsRtlIsNameInExpression.
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Arguments:
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ConstantNameA - Constant name.
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ConstantNameB - Constant name.
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IgnoreCase - TRUE if the Names should be Upcased before comparing.
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UpcaseTable - If supplied, use this table for case insensitive compares,
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otherwise, use the default system upcase table.
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Return Value:
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BOOLEAN - TRUE if the two names are lexically equal.
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--*/
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{
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ULONG Index;
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ULONG NameLength;
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BOOLEAN FreeStrings = FALSE;
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UNICODE_STRING LocalNameA;
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UNICODE_STRING LocalNameB;
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PAGED_CODE();
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//
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// If the names aren't even the same size, then return FALSE right away.
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//
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if ( ConstantNameA->Length != ConstantNameB->Length ) {
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return FALSE;
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}
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NameLength = ConstantNameA->Length / sizeof(WCHAR);
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//
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// If we weren't given an upcase table, we have to upcase the names
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// ourselves.
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//
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if ( IgnoreCase && !ARGUMENT_PRESENT(UpcaseTable) ) {
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NTSTATUS Status;
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Status = RtlUpcaseUnicodeString( &LocalNameA, ConstantNameA, TRUE );
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if ( !NT_SUCCESS(Status) ) {
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ExRaiseStatus( Status );
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}
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Status = RtlUpcaseUnicodeString( &LocalNameB, ConstantNameB, TRUE );
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if ( !NT_SUCCESS(Status) ) {
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RtlFreeUnicodeString( &LocalNameA );
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ExRaiseStatus( Status );
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}
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ConstantNameA = &LocalNameA;
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ConstantNameB = &LocalNameB;
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IgnoreCase = FALSE;
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FreeStrings = TRUE;
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}
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//
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// Do either case sensitive or insensitive compare.
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//
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if ( !IgnoreCase ) {
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BOOLEAN BytesEqual;
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BytesEqual = (BOOLEAN) RtlEqualMemory( ConstantNameA->Buffer,
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ConstantNameB->Buffer,
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ConstantNameA->Length );
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if ( FreeStrings ) {
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RtlFreeUnicodeString( &LocalNameA );
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RtlFreeUnicodeString( &LocalNameB );
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}
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return BytesEqual;
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} else {
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for (Index = 0; Index < NameLength; Index += 1) {
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if ( UpcaseTable[ConstantNameA->Buffer[Index]] !=
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UpcaseTable[ConstantNameB->Buffer[Index]] ) {
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return FALSE;
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}
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||
}
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||
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return TRUE;
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}
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}
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|
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|
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//
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// The following routine is just a wrapper around
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// FsRtlIsNameInExpressionPrivate to make a last minute fix a bit safer.
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||
//
|
||
|
||
BOOLEAN
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FsRtlIsNameInExpression (
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IN PUNICODE_STRING Expression,
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IN PUNICODE_STRING Name,
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IN BOOLEAN IgnoreCase,
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||
IN PWCH UpcaseTable OPTIONAL
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||
)
|
||
|
||
{
|
||
BOOLEAN Result = FALSE;
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||
UNICODE_STRING LocalName;
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|
||
//
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||
// If we weren't given an upcase table, we have to upcase the names
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// ourselves.
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||
//
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||
|
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if ( IgnoreCase && !ARGUMENT_PRESENT(UpcaseTable) ) {
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NTSTATUS Status;
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Status = RtlUpcaseUnicodeString( &LocalName, Name, TRUE );
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|
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if ( !NT_SUCCESS(Status) ) {
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ExRaiseStatus( Status );
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||
}
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||
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||
Name = &LocalName;
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IgnoreCase = FALSE;
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||
|
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} else {
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||
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||
LocalName.Buffer = NULL;
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}
|
||
|
||
//
|
||
// Now call the main routine, remembering to free the upcased string
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// if we allocated one.
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||
//
|
||
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||
try {
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||
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Result = FsRtlIsNameInExpressionPrivate( Expression,
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Name,
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IgnoreCase,
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UpcaseTable );
|
||
|
||
} finally {
|
||
|
||
if (LocalName.Buffer != NULL) {
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||
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||
RtlFreeUnicodeString( &LocalName );
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||
}
|
||
}
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||
|
||
return Result;
|
||
}
|
||
|
||
|
||
#define MATCHES_ARRAY_SIZE 16
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||
|
||
//
|
||
// Local support routine prototypes
|
||
//
|
||
|
||
BOOLEAN
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||
FsRtlIsNameInExpressionPrivate (
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IN PUNICODE_STRING Expression,
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IN PUNICODE_STRING Name,
|
||
IN BOOLEAN IgnoreCase,
|
||
IN PWCH UpcaseTable
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||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine compares a Dbcs name and an expression and tells the caller
|
||
if the name is in the language defined by the expression. The input name
|
||
cannot contain wildcards, while the expression may contain wildcards.
|
||
|
||
Expression wild cards are evaluated as shown in the nondeterministic
|
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finite automatons below. Note that ~* and ~? are DOS_STAR and DOS_QM.
|
||
|
||
|
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~* is DOS_STAR, ~? is DOS_QM, and ~. is DOS_DOT
|
||
|
||
|
||
S
|
||
<-----<
|
||
X | | e Y
|
||
X * Y == (0)----->-(1)->-----(2)-----(3)
|
||
|
||
|
||
S-.
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||
<-----<
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||
X | | e Y
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||
X ~* Y == (0)----->-(1)->-----(2)-----(3)
|
||
|
||
|
||
|
||
X S S Y
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X ?? Y == (0)---(1)---(2)---(3)---(4)
|
||
|
||
|
||
|
||
X . . Y
|
||
X ~.~. Y == (0)---(1)----(2)------(3)---(4)
|
||
| |________|
|
||
| ^ |
|
||
|_______________|
|
||
^EOF or .^
|
||
|
||
|
||
X S-. S-. Y
|
||
X ~?~? Y == (0)---(1)-----(2)-----(3)---(4)
|
||
| |________|
|
||
| ^ |
|
||
|_______________|
|
||
^EOF or .^
|
||
|
||
|
||
|
||
where S is any single character
|
||
|
||
S-. is any single character except the final .
|
||
|
||
e is a null character transition
|
||
|
||
EOF is the end of the name string
|
||
|
||
In words:
|
||
|
||
* matches 0 or more characters.
|
||
|
||
? matches exactly 1 character.
|
||
|
||
DOS_STAR matches 0 or more characters until encountering and matching
|
||
the final . in the name.
|
||
|
||
DOS_QM matches any single character, or upon encountering a period or
|
||
end of name string, advances the expression to the end of the
|
||
set of contiguous DOS_QMs.
|
||
|
||
DOS_DOT matches either a . or zero characters beyond name string.
|
||
|
||
Arguments:
|
||
|
||
Expression - Supplies the input expression to check against
|
||
(Caller must already upcase if passing CaseInsensitive TRUE.)
|
||
|
||
Name - Supplies the input name to check for.
|
||
|
||
CaseInsensitive - TRUE if Name should be Upcased before comparing.
|
||
|
||
Return Value:
|
||
|
||
BOOLEAN - TRUE if Name is an element in the set of strings denoted
|
||
by the input Expression and FALSE otherwise.
|
||
|
||
--*/
|
||
|
||
{
|
||
USHORT NameOffset;
|
||
USHORT ExprOffset;
|
||
|
||
ULONG SrcCount;
|
||
ULONG DestCount;
|
||
ULONG PreviousDestCount;
|
||
ULONG MatchesCount;
|
||
|
||
WCHAR NameChar = 0, ExprChar;
|
||
|
||
USHORT LocalBuffer[MATCHES_ARRAY_SIZE * 2];
|
||
|
||
USHORT *AuxBuffer = NULL;
|
||
USHORT *PreviousMatches;
|
||
USHORT *CurrentMatches;
|
||
|
||
USHORT MaxState;
|
||
USHORT CurrentState;
|
||
|
||
BOOLEAN NameFinished = FALSE;
|
||
|
||
//
|
||
// The idea behind the algorithm is pretty simple. We keep track of
|
||
// all possible locations in the regular expression that are matching
|
||
// the name. If when the name has been exhausted one of the locations
|
||
// in the expression is also just exhausted, the name is in the language
|
||
// defined by the regular expression.
|
||
//
|
||
|
||
PAGED_CODE();
|
||
|
||
DebugTrace(+1, Dbg, "FsRtlIsNameInExpression\n", 0);
|
||
DebugTrace( 0, Dbg, " Expression = %Z\n", Expression );
|
||
DebugTrace( 0, Dbg, " Name = %Z\n", Name );
|
||
DebugTrace( 0, Dbg, " CaseInsensitive = %08lx\n", CaseInsensitive );
|
||
|
||
//
|
||
// If one string is empty return FALSE. If both are empty return TRUE.
|
||
//
|
||
|
||
if ( (Name->Length == 0) || (Expression->Length == 0) ) {
|
||
|
||
return (BOOLEAN)(!(Name->Length + Expression->Length));
|
||
}
|
||
|
||
//
|
||
// Special case by far the most common wild card search of *
|
||
//
|
||
|
||
if ((Expression->Length == 2) && (Expression->Buffer[0] == L'*')) {
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
ASSERT( !IgnoreCase || ARGUMENT_PRESENT(UpcaseTable) );
|
||
|
||
//
|
||
// Also special case expressions of the form *X. With this and the prior
|
||
// case we have covered virtually all normal queries.
|
||
//
|
||
|
||
if (Expression->Buffer[0] == L'*') {
|
||
|
||
UNICODE_STRING LocalExpression;
|
||
|
||
LocalExpression = *Expression;
|
||
|
||
LocalExpression.Buffer += 1;
|
||
LocalExpression.Length -= 2;
|
||
|
||
//
|
||
// Only special case an expression with a single *
|
||
//
|
||
|
||
if ( !FsRtlDoesNameContainWildCards( &LocalExpression ) ) {
|
||
|
||
ULONG StartingNameOffset;
|
||
|
||
if (Name->Length < (USHORT)(Expression->Length - sizeof(WCHAR))) {
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
StartingNameOffset = ( Name->Length -
|
||
LocalExpression.Length ) / sizeof(WCHAR);
|
||
|
||
//
|
||
// Do a simple memory compare if case sensitive, otherwise
|
||
// we have got to check this one character at a time.
|
||
//
|
||
|
||
if ( !IgnoreCase ) {
|
||
|
||
return (BOOLEAN) RtlEqualMemory( LocalExpression.Buffer,
|
||
Name->Buffer + StartingNameOffset,
|
||
LocalExpression.Length );
|
||
|
||
} else {
|
||
|
||
for ( ExprOffset = 0;
|
||
ExprOffset < (USHORT)(LocalExpression.Length / sizeof(WCHAR));
|
||
ExprOffset += 1 ) {
|
||
|
||
NameChar = Name->Buffer[StartingNameOffset + ExprOffset];
|
||
NameChar = UpcaseTable[NameChar];
|
||
|
||
ExprChar = LocalExpression.Buffer[ExprOffset];
|
||
|
||
ASSERT( ExprChar == UpcaseTable[ExprChar] );
|
||
|
||
if ( NameChar != ExprChar ) {
|
||
|
||
return FALSE;
|
||
}
|
||
}
|
||
|
||
return TRUE;
|
||
}
|
||
}
|
||
}
|
||
|
||
//
|
||
// Walk through the name string, picking off characters. We go one
|
||
// character beyond the end because some wild cards are able to match
|
||
// zero characters beyond the end of the string.
|
||
//
|
||
// With each new name character we determine a new set of states that
|
||
// match the name so far. We use two arrays that we swap back and forth
|
||
// for this purpose. One array lists the possible expression states for
|
||
// all name characters up to but not including the current one, and other
|
||
// array is used to build up the list of states considering the current
|
||
// name character as well. The arrays are then switched and the process
|
||
// repeated.
|
||
//
|
||
// There is not a one-to-one correspondence between state number and
|
||
// offset into the expression. This is evident from the NFAs in the
|
||
// initial comment to this function. State numbering is not continuous.
|
||
// This allows a simple conversion between state number and expression
|
||
// offset. Each character in the expression can represent one or two
|
||
// states. * and DOS_STAR generate two states: ExprOffset*2 and
|
||
// ExprOffset*2 + 1. All other expreesion characters can produce only
|
||
// a single state. Thus ExprOffset = State/2.
|
||
//
|
||
//
|
||
// Here is a short description of the variables involved:
|
||
//
|
||
// NameOffset - The offset of the current name char being processed.
|
||
//
|
||
// ExprOffset - The offset of the current expression char being processed.
|
||
//
|
||
// SrcCount - Prior match being investigated with current name char
|
||
//
|
||
// DestCount - Next location to put a matching assuming current name char
|
||
//
|
||
// NameFinished - Allows one more itteration through the Matches array
|
||
// after the name is exhusted (to come *s for example)
|
||
//
|
||
// PreviousDestCount - This is used to prevent entry duplication, see coment
|
||
//
|
||
// PreviousMatches - Holds the previous set of matches (the Src array)
|
||
//
|
||
// CurrentMatches - Holds the current set of matches (the Dest array)
|
||
//
|
||
// AuxBuffer, LocalBuffer - the storage for the Matches arrays
|
||
//
|
||
|
||
//
|
||
// Set up the initial variables
|
||
//
|
||
|
||
PreviousMatches = &LocalBuffer[0];
|
||
CurrentMatches = &LocalBuffer[MATCHES_ARRAY_SIZE];
|
||
|
||
PreviousMatches[0] = 0;
|
||
MatchesCount = 1;
|
||
|
||
NameOffset = 0;
|
||
|
||
MaxState = (USHORT)(Expression->Length * 2);
|
||
|
||
while ( !NameFinished ) {
|
||
|
||
if ( NameOffset < Name->Length ) {
|
||
|
||
NameChar = Name->Buffer[NameOffset / sizeof(WCHAR)];
|
||
|
||
NameOffset += sizeof(WCHAR);;
|
||
|
||
} else {
|
||
|
||
NameFinished = TRUE;
|
||
|
||
//
|
||
// if we have already exhasted the expression, cool. Don't
|
||
// continue.
|
||
//
|
||
|
||
if ( PreviousMatches[MatchesCount-1] == MaxState ) {
|
||
|
||
break;
|
||
}
|
||
}
|
||
|
||
|
||
//
|
||
// Now, for each of the previous stored expression matches, see what
|
||
// we can do with this name character.
|
||
//
|
||
|
||
SrcCount = 0;
|
||
DestCount = 0;
|
||
PreviousDestCount = 0;
|
||
|
||
while ( SrcCount < MatchesCount ) {
|
||
|
||
USHORT Length;
|
||
|
||
//
|
||
// We have to carry on our expression analysis as far as possible
|
||
// for each character of name, so we loop here until the
|
||
// expression stops matching. A clue here is that expression
|
||
// cases that can match zero or more characters end with a
|
||
// continue, while those that can accept only a single character
|
||
// end with a break.
|
||
//
|
||
|
||
ExprOffset = (USHORT)((PreviousMatches[SrcCount++] + 1) / 2);
|
||
|
||
|
||
Length = 0;
|
||
|
||
while ( TRUE ) {
|
||
|
||
if ( ExprOffset == Expression->Length ) {
|
||
|
||
break;
|
||
}
|
||
|
||
//
|
||
// The first time through the loop we don't want
|
||
// to increment ExprOffset.
|
||
//
|
||
|
||
ExprOffset = (USHORT)(ExprOffset + Length);
|
||
Length = sizeof(WCHAR);
|
||
|
||
CurrentState = (USHORT)(ExprOffset * 2);
|
||
|
||
if ( ExprOffset == Expression->Length ) {
|
||
|
||
CurrentMatches[DestCount++] = MaxState;
|
||
break;
|
||
}
|
||
|
||
ExprChar = Expression->Buffer[ExprOffset / sizeof(WCHAR)];
|
||
|
||
ASSERT( !IgnoreCase || !((ExprChar >= L'a') && (ExprChar <= L'z')) );
|
||
|
||
//
|
||
// Before we get started, we have to check for something
|
||
// really gross. We may be about to exhaust the local
|
||
// space for ExpressionMatches[][], so we have to allocate
|
||
// some pool if this is the case. Yuk!
|
||
//
|
||
|
||
if ( (DestCount >= MATCHES_ARRAY_SIZE - 2) &&
|
||
(AuxBuffer == NULL) ) {
|
||
|
||
ULONG ExpressionChars;
|
||
|
||
ExpressionChars = Expression->Length / sizeof(WCHAR);
|
||
|
||
AuxBuffer = FsRtlpAllocatePool( PagedPool,
|
||
(ExpressionChars+1) *
|
||
sizeof(USHORT)*2*2 );
|
||
|
||
RtlCopyMemory( AuxBuffer,
|
||
CurrentMatches,
|
||
MATCHES_ARRAY_SIZE * sizeof(USHORT) );
|
||
|
||
CurrentMatches = AuxBuffer;
|
||
|
||
RtlCopyMemory( AuxBuffer + (ExpressionChars+1)*2,
|
||
PreviousMatches,
|
||
MATCHES_ARRAY_SIZE * sizeof(USHORT) );
|
||
|
||
PreviousMatches = AuxBuffer + (ExpressionChars+1)*2;
|
||
}
|
||
|
||
//
|
||
// * matches any character zero or more times.
|
||
//
|
||
|
||
if (ExprChar == L'*') {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
CurrentMatches[DestCount++] = CurrentState + 3;
|
||
continue;
|
||
}
|
||
|
||
//
|
||
// DOS_STAR matches any character except . zero or more times.
|
||
//
|
||
|
||
if (ExprChar == DOS_STAR) {
|
||
|
||
BOOLEAN ICanEatADot = FALSE;
|
||
|
||
//
|
||
// If we are at a period, determine if we are allowed to
|
||
// consume it, ie. make sure it is not the last one.
|
||
//
|
||
|
||
if ( !NameFinished && (NameChar == '.') ) {
|
||
|
||
USHORT Offset;
|
||
|
||
for ( Offset = NameOffset;
|
||
Offset < Name->Length;
|
||
Offset = (USHORT)(Offset + Length) ) {
|
||
|
||
if (Name->Buffer[Offset / sizeof(WCHAR)] == L'.') {
|
||
|
||
ICanEatADot = TRUE;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (NameFinished || (NameChar != L'.') || ICanEatADot) {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
CurrentMatches[DestCount++] = CurrentState + 3;
|
||
continue;
|
||
|
||
} else {
|
||
|
||
//
|
||
// We are at a period. We can only match zero
|
||
// characters (ie. the epsilon transition).
|
||
//
|
||
|
||
CurrentMatches[DestCount++] = CurrentState + 3;
|
||
continue;
|
||
}
|
||
}
|
||
|
||
//
|
||
// The following expreesion characters all match by consuming
|
||
// a character, thus force the expression, and thus state
|
||
// forward.
|
||
//
|
||
|
||
CurrentState += (USHORT)(sizeof(WCHAR) * 2);
|
||
|
||
//
|
||
// DOS_QM is the most complicated. If the name is finished,
|
||
// we can match zero characters. If this name is a '.', we
|
||
// don't match, but look at the next expression. Otherwise
|
||
// we match a single character.
|
||
//
|
||
|
||
if ( ExprChar == DOS_QM ) {
|
||
|
||
if ( NameFinished || (NameChar == L'.') ) {
|
||
|
||
continue;
|
||
}
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
break;
|
||
}
|
||
|
||
//
|
||
// A DOS_DOT can match either a period, or zero characters
|
||
// beyond the end of name.
|
||
//
|
||
|
||
if (ExprChar == DOS_DOT) {
|
||
|
||
if ( NameFinished ) {
|
||
|
||
continue;
|
||
}
|
||
|
||
if (NameChar == L'.') {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
break;
|
||
}
|
||
}
|
||
|
||
//
|
||
// From this point on a name character is required to even
|
||
// continue, let alone make a match.
|
||
//
|
||
|
||
if ( NameFinished ) {
|
||
|
||
break;
|
||
}
|
||
|
||
//
|
||
// If this expression was a '?' we can match it once.
|
||
//
|
||
|
||
if (ExprChar == L'?') {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
break;
|
||
}
|
||
|
||
//
|
||
// Finally, check if the expression char matches the name char
|
||
//
|
||
|
||
if (ExprChar == (WCHAR)(IgnoreCase ?
|
||
UpcaseTable[NameChar] : NameChar)) {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
break;
|
||
}
|
||
|
||
//
|
||
// The expression didn't match so go look at the next
|
||
// previous match.
|
||
//
|
||
|
||
break;
|
||
}
|
||
|
||
|
||
//
|
||
// Prevent duplication in the destination array.
|
||
//
|
||
// Each of the arrays is montonically increasing and non-
|
||
// duplicating, thus we skip over any source element in the src
|
||
// array if we just added the same element to the destination
|
||
// array. This guarentees non-duplication in the dest. array.
|
||
//
|
||
|
||
while ((SrcCount < MatchesCount) &&
|
||
(PreviousDestCount < DestCount)) {
|
||
|
||
while ((SrcCount < MatchesCount) &&
|
||
(PreviousMatches[SrcCount] <
|
||
CurrentMatches[PreviousDestCount])) {
|
||
|
||
SrcCount += 1;
|
||
}
|
||
|
||
PreviousDestCount += 1;
|
||
}
|
||
}
|
||
|
||
//
|
||
// If we found no matches in the just finished itteration, it's time
|
||
// to bail.
|
||
//
|
||
|
||
if ( DestCount == 0 ) {
|
||
|
||
if (AuxBuffer != NULL) { ExFreePool( AuxBuffer ); }
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
//
|
||
// Swap the meaning the two arrays
|
||
//
|
||
|
||
{
|
||
USHORT *Tmp;
|
||
|
||
Tmp = PreviousMatches;
|
||
|
||
PreviousMatches = CurrentMatches;
|
||
|
||
CurrentMatches = Tmp;
|
||
}
|
||
|
||
MatchesCount = DestCount;
|
||
}
|
||
|
||
|
||
CurrentState = PreviousMatches[MatchesCount-1];
|
||
|
||
if (AuxBuffer != NULL) { ExFreePool( AuxBuffer ); }
|
||
|
||
|
||
return (BOOLEAN)(CurrentState == MaxState);
|
||
}
|
||
|