1352 lines
36 KiB
C
1352 lines
36 KiB
C
/*++
|
||
|
||
Copyright (c) 1989 Microsoft Corporation
|
||
|
||
Module Name:
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||
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DbcsName.c
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||
|
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Abstract:
|
||
|
||
The name support package is for manipulating DBCS strings. The routines
|
||
allow the caller to dissect and compare strings.
|
||
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The following routines are provided by this package:
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||
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||
o FsRtlIsFatDbcsLegal - This routine takes an input dbcs
|
||
string and determines if it describes a legal name or path.
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||
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o FsRtlIsHpfsDbcsLegal - This routine takes an input dbcs
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||
string and determines if it describes a legal name or path.
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||
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o FsRtlDissectDbcs - This routine takes a path name string and
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breaks into two parts. The first name in the string and the
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remainder.
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o FsRtlDoesDbcsContainWildCards - This routines tells the caller if
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a string contains any wildcard characters.
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||
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o FsRtlIsDbcsInExpression - 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 code
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//
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#if DBG
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ULONG DaveDebug = 0;
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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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||
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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 ('drSF')
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, FsRtlDissectDbcs)
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#pragma alloc_text(PAGE, FsRtlDoesDbcsContainWildCards)
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#pragma alloc_text(PAGE, FsRtlIsDbcsInExpression)
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#pragma alloc_text(PAGE, FsRtlIsFatDbcsLegal)
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#pragma alloc_text(PAGE, FsRtlIsHpfsDbcsLegal)
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#endif
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BOOLEAN
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FsRtlIsFatDbcsLegal (
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IN ANSI_STRING DbcsName,
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IN BOOLEAN WildCardsPermissible,
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IN BOOLEAN PathNamePermissible,
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IN BOOLEAN LeadingBackslashPermissible
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)
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/*++
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Routine Description:
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This routine simple returns whether the specified file names conforms
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to the file system specific rules for legal file names. This routine
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will check the single name, or if PathNamePermissible is specified as
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TRUE, whether the whole path is a legal name.
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For FAT, the following rules apply:
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A. A Fat file name may not contain any of the following characters:
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0x00-0x1F " / : | + , ; = [ ]
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B. A Fat file name is either of the form N.E or just N, where N is a
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string of 1-8 bytes and E is a string of 1-3 bytes conformant to
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rule A above. In addition, neither N nor E may contain a period
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character or end with a space character.
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Incidently, N corresponds to name and E to extension.
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Case: Lower case characters are taken as valid, but are up-shifted upon
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receipt, ie. Fat only deals with upper case file names.
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For example, the files ".foo", "foo.", and "foo .b" are illegal, while
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"foo. b" and " bar" are legal.
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Arguments:
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DbcsName - Supllies the name/path to check.
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WildCardsPermissible - Specifies if Nt wild card characters are to be
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considered considered legal.
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PathNamePermissible - Spcifes if Name may be a path name separated by
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backslash characters, or just a simple file name.
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LeadingBackSlashPermissible - Specifies if a single leading backslash
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is permissible in the file/path name.
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Return Value:
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BOOLEAN - TRUE if the name is legal, FALSE otherwise.
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--*/
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{
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BOOLEAN ExtensionPresent = FALSE;
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ULONG Index;
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UCHAR Char;
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PAGED_CODE();
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//
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// Empty names are not valid.
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//
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if ( DbcsName.Length == 0 ) { return FALSE; }
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//
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// If Wild Cards are OK, then for directory enumeration to work
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// correctly we have to accept . and ..
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//
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if ( WildCardsPermissible &&
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( ( (DbcsName.Length == 1) &&
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((DbcsName.Buffer[0] == '.') ||
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(DbcsName.Buffer[0] == ANSI_DOS_DOT)) )
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||
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( (DbcsName.Length == 2) &&
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( ((DbcsName.Buffer[0] == '.') &&
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(DbcsName.Buffer[1] == '.')) ||
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((DbcsName.Buffer[0] == ANSI_DOS_DOT) &&
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(DbcsName.Buffer[1] == ANSI_DOS_DOT)) ) ) ) ) {
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return TRUE;
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}
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//
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// If a leading \ is OK, skip over it (if there's more)
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//
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if ( DbcsName.Buffer[0] == '\\' ) {
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if ( LeadingBackslashPermissible ) {
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if ( (DbcsName.Length > 1) ) {
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DbcsName.Buffer += 1;
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DbcsName.Length -= 1;
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} else { return TRUE; }
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} else { return FALSE; }
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}
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//
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// If we got a path name, check each componant.
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//
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if ( PathNamePermissible ) {
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ANSI_STRING FirstName;
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ANSI_STRING RemainingName;
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RemainingName = DbcsName;
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while ( RemainingName.Length != 0 ) {
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//
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// This will catch the case of an illegal double backslash.
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//
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if ( RemainingName.Buffer[0] == '\\' ) { return FALSE; }
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FsRtlDissectDbcs(RemainingName, &FirstName, &RemainingName);
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if ( !FsRtlIsFatDbcsLegal( FirstName,
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WildCardsPermissible,
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FALSE,
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FALSE) ) {
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return FALSE;
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}
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}
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//
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// All the componants were OK, so the path is OK.
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//
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return TRUE;
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}
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//
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// If this name contains wild cards, just check for invalid characters.
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//
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if ( WildCardsPermissible && FsRtlDoesDbcsContainWildCards(&DbcsName) ) {
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for ( Index = 0; Index < DbcsName.Length; Index += 1 ) {
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Char = DbcsName.Buffer[ Index ];
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//
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// Skip over any Dbcs chacters
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//
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if ( FsRtlIsLeadDbcsCharacter( Char ) ) {
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ASSERT( Index != (ULONG)(DbcsName.Length - 1) );
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Index += 1;
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continue;
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}
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//
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// Make sure this character is legal, and if a wild card, that
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// wild cards are permissible.
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//
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if ( !FsRtlIsAnsiCharacterLegalFat(Char, WildCardsPermissible) ) {
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return FALSE;
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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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// At this point we should only have a single name, which can't have
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// more than 12 characters (including a single period)
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//
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if ( DbcsName.Length > 12 ) { return FALSE; }
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for ( Index = 0; Index < DbcsName.Length; Index += 1 ) {
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Char = DbcsName.Buffer[ Index ];
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//
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// Skip over and Dbcs chacters
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//
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if ( FsRtlIsLeadDbcsCharacter( Char ) ) {
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//
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// FsRtlIsFatDbcsLegal(): fat name part and extension part dbcs check
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//
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// 1) if we're looking at base part ( !ExtensionPresent ) and the 8th byte
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// is in the dbcs leading byte range, it's error ( Index == 7 ). If the
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// length of base part is more than 8 ( Index > 7 ), it's definitely error.
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//
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// 2) if the last byte ( Index == DbcsName.Length - 1 ) is in the dbcs leading
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// byte range, it's error
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//
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if ( (!ExtensionPresent && (Index >= 7)) ||
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( Index == (ULONG)(DbcsName.Length - 1) ) ) {
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return FALSE;
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}
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Index += 1;
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continue;
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}
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//
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// Make sure this character is legal, and if a wild card, that
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// wild cards are permissible.
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//
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if ( !FsRtlIsAnsiCharacterLegalFat(Char, WildCardsPermissible) ) {
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return FALSE;
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}
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if ( (Char == '.') || (Char == ANSI_DOS_DOT) ) {
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//
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// We stepped onto a period. We require the following things:
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//
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// - It can't be the first character
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// - There can only be one
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// - There can't be more than three characters following
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// - The previous character can't be a space.
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//
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if ( (Index == 0) ||
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ExtensionPresent ||
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(DbcsName.Length - (Index + 1) > 3) ||
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(DbcsName.Buffer[Index - 1] == ' ') ) {
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return FALSE;
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}
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ExtensionPresent = TRUE;
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}
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||
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//
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||
// The base part of the name can't be more than 8 characters long.
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//
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if ( (Index >= 8) && !ExtensionPresent ) { return FALSE; }
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}
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//
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// The name cannot end in a space or a period.
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//
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if ( (Char == ' ') || (Char == '.') || (Char == ANSI_DOS_DOT)) { return FALSE; }
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return TRUE;
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}
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BOOLEAN
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FsRtlIsHpfsDbcsLegal (
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IN ANSI_STRING DbcsName,
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IN BOOLEAN WildCardsPermissible,
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IN BOOLEAN PathNamePermissible,
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||
IN BOOLEAN LeadingBackslashPermissible
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||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine simple returns whether the specified file names conforms
|
||
to the file system specific rules for legal file names. This routine
|
||
will check the single name, or if PathNamePermissible is specified as
|
||
TRUE, whether the whole path is a legal name.
|
||
|
||
For HPFS, the following rules apply:
|
||
|
||
A. An HPFS file name may not contain any of the following characters:
|
||
|
||
0x0000 - 0x001F " / : < > ? | *
|
||
|
||
B. An HPFS file name may not end in a period or a space.
|
||
|
||
C. An HPFS file name must contain no more than 255 bytes.
|
||
|
||
Case: HPFS is case preserving, but not case sensitive. Case is
|
||
preserved on creates, but not checked for on file name compares.
|
||
|
||
For example, the files "foo " and "foo." are illegal, while ".foo",
|
||
" foo" and "foo.bar.foo" are legal.
|
||
|
||
Arguments:
|
||
|
||
DbcsName - Supllies the name/path to check.
|
||
|
||
WildCardsPermissible - Specifies if Nt wild card characters are to be
|
||
considered considered legal.
|
||
|
||
PathNamePermissible - Spcifes if Name may be a path name separated by
|
||
backslash characters, or just a simple file name.
|
||
|
||
LeadingBackSlashPermissible - Specifies if a single leading backslash
|
||
is permissible in the file/path name.
|
||
|
||
Return Value:
|
||
|
||
BOOLEAN - TRUE if the name is legal, FALSE otherwise.
|
||
|
||
--*/
|
||
{
|
||
BOOLEAN ExtensionPresent = FALSE;
|
||
|
||
ULONG Index;
|
||
|
||
UCHAR Char;
|
||
|
||
PAGED_CODE();
|
||
|
||
//
|
||
// Empty names are not valid.
|
||
//
|
||
|
||
if ( DbcsName.Length == 0 ) { return FALSE; }
|
||
|
||
//
|
||
// If Wild Cards are OK, then for directory enumeration to work
|
||
// correctly we have to accept . and ..
|
||
//
|
||
|
||
if ( WildCardsPermissible &&
|
||
( ( (DbcsName.Length == 1) &&
|
||
((DbcsName.Buffer[0] == '.') ||
|
||
(DbcsName.Buffer[0] == ANSI_DOS_DOT)) )
|
||
||
|
||
( (DbcsName.Length == 2) &&
|
||
( ((DbcsName.Buffer[0] == '.') &&
|
||
(DbcsName.Buffer[1] == '.')) ||
|
||
((DbcsName.Buffer[0] == ANSI_DOS_DOT) &&
|
||
(DbcsName.Buffer[1] == ANSI_DOS_DOT)) ) ) ) ) {
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
//
|
||
// If a leading \ is OK, skip over it (if there's more)
|
||
//
|
||
|
||
if ( DbcsName.Buffer[0] == '\\' ) {
|
||
|
||
if ( LeadingBackslashPermissible ) {
|
||
|
||
if ( (DbcsName.Length > 1) ) {
|
||
|
||
DbcsName.Buffer += 1;
|
||
DbcsName.Length -= 1;
|
||
|
||
} else { return TRUE; }
|
||
|
||
} else { return FALSE; }
|
||
}
|
||
|
||
//
|
||
// If we got a path name, check each componant.
|
||
//
|
||
|
||
if ( PathNamePermissible ) {
|
||
|
||
ANSI_STRING FirstName;
|
||
ANSI_STRING RemainingName;
|
||
|
||
RemainingName = DbcsName;
|
||
|
||
while ( RemainingName.Length != 0 ) {
|
||
|
||
//
|
||
// This will catch the case of an illegal double backslash.
|
||
//
|
||
|
||
if ( RemainingName.Buffer[0] == '\\' ) { return FALSE; }
|
||
|
||
FsRtlDissectDbcs(RemainingName, &FirstName, &RemainingName);
|
||
|
||
if ( !FsRtlIsHpfsDbcsLegal( FirstName,
|
||
WildCardsPermissible,
|
||
FALSE,
|
||
FALSE) ) {
|
||
|
||
return FALSE;
|
||
}
|
||
}
|
||
|
||
//
|
||
// All the componants were OK, so the path is OK.
|
||
//
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
//
|
||
// At this point we should only have a single name, which can't have
|
||
// more than 255 characters
|
||
//
|
||
|
||
if ( DbcsName.Length > 255 ) { return FALSE; }
|
||
|
||
for ( Index = 0; Index < DbcsName.Length; Index += 1 ) {
|
||
|
||
Char = DbcsName.Buffer[ Index ];
|
||
|
||
//
|
||
// Skip over and Dbcs chacters
|
||
//
|
||
|
||
if ( FsRtlIsLeadDbcsCharacter( Char ) ) {
|
||
|
||
//
|
||
// FsRtlIsHpfsDbcsLegal () hpfs dbcs check
|
||
//
|
||
// If the last byte ( Index == DbcsName.Length - 1 ) is in the
|
||
// dbcs leading byte range, it's error.
|
||
//
|
||
|
||
if ( Index == (ULONG)(DbcsName.Length - 1) ) {
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
Index += 1;
|
||
continue;
|
||
}
|
||
|
||
//
|
||
// Make sure this character is legal, and if a wild card, that
|
||
// wild cards are permissible.
|
||
//
|
||
|
||
if ( !FsRtlIsAnsiCharacterLegalHpfs(Char, WildCardsPermissible) ) {
|
||
|
||
return FALSE;
|
||
}
|
||
}
|
||
|
||
//
|
||
// The name cannot end in a space or a period.
|
||
//
|
||
|
||
if ( (Char == ' ') || (Char == '.') || (Char == ANSI_DOS_DOT) ) {
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
|
||
VOID
|
||
FsRtlDissectDbcs (
|
||
IN ANSI_STRING Path,
|
||
OUT PANSI_STRING FirstName,
|
||
OUT PANSI_STRING RemainingName
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine takes an input Dbcs string and dissects it into two
|
||
substrings. The first output string contains the name that appears at
|
||
the beginning of the input string, the second output string contains the
|
||
remainder of the input string.
|
||
|
||
In the input string backslashes are used to separate names. The input
|
||
string must not start with a backslash. Both output strings will not
|
||
begin with a backslash.
|
||
|
||
If the input string does not contain any names then both output strings
|
||
are empty. If the input string contains only one name then the first
|
||
output string contains the name and the second string is empty.
|
||
|
||
Note that both output strings use the same string buffer memory of the
|
||
input string.
|
||
|
||
Example of its results are:
|
||
|
||
//. . InputString FirstPart RemainingPart
|
||
//
|
||
//. . empty empty empty
|
||
//
|
||
//. . A A empty
|
||
//
|
||
//. . A\B\C\D\E A B\C\D\E
|
||
//
|
||
//. . *A? *A? empty
|
||
//
|
||
//. . \A A empty
|
||
//
|
||
//. . A[,] A[,] empty
|
||
//
|
||
//. . A\\B+;\C A \B+;\C
|
||
|
||
Arguments:
|
||
|
||
InputName - Supplies the input string being dissected
|
||
|
||
Is8dot3 - Indicates if the first part of the input name must be 8.3
|
||
or can be long file name.
|
||
|
||
FirstPart - Receives the first name in the input string
|
||
|
||
RemainingPart - Receives the remaining part of the input string
|
||
|
||
Return Value:
|
||
|
||
NONE
|
||
|
||
--*/
|
||
|
||
{
|
||
ULONG i = 0;
|
||
ULONG PathLength;
|
||
ULONG FirstNameStart;
|
||
|
||
PAGED_CODE();
|
||
|
||
//
|
||
// Make both output strings empty for now
|
||
//
|
||
|
||
FirstName->Length = 0;
|
||
FirstName->MaximumLength = 0;
|
||
FirstName->Buffer = NULL;
|
||
|
||
RemainingName->Length = 0;
|
||
RemainingName->MaximumLength = 0;
|
||
RemainingName->Buffer = NULL;
|
||
|
||
PathLength = Path.Length;
|
||
|
||
//
|
||
// Check for an empty input string
|
||
//
|
||
|
||
if (PathLength == 0) {
|
||
|
||
return;
|
||
}
|
||
|
||
//
|
||
// Skip over a starting backslash, and make sure there is more.
|
||
//
|
||
|
||
if ( Path.Buffer[0] == '\\' ) {
|
||
|
||
i = 1;
|
||
}
|
||
|
||
//
|
||
// Now run down the input string until we hit a backslash or the end
|
||
// of the string, remembering where we started;
|
||
//
|
||
|
||
for ( FirstNameStart = i;
|
||
(i < PathLength) && (Path.Buffer[i] != '\\');
|
||
i += 1 ) {
|
||
|
||
//
|
||
// If this is the first byte of a Dbcs character, skip over the
|
||
// next byte as well.
|
||
//
|
||
|
||
if ( FsRtlIsLeadDbcsCharacter( Path.Buffer[i] ) ) {
|
||
|
||
i += 1;
|
||
}
|
||
}
|
||
|
||
//
|
||
// At this point all characters up to (but not including) i are
|
||
// in the first part. So setup the first name
|
||
//
|
||
|
||
FirstName->Length = (USHORT)(i - FirstNameStart);
|
||
FirstName->MaximumLength = FirstName->Length;
|
||
FirstName->Buffer = &Path.Buffer[FirstNameStart];
|
||
|
||
//
|
||
// Now the remaining part needs a string only if the first part didn't
|
||
// exhaust the entire input string. We know that if anything is left
|
||
// that is must start with a backslash. Note that if there is only
|
||
// a trailing backslash, the length will get correctly set to zero.
|
||
//
|
||
|
||
if (i < PathLength) {
|
||
|
||
RemainingName->Length = (USHORT)(PathLength - (i + 1));
|
||
RemainingName->MaximumLength = RemainingName->Length;
|
||
RemainingName->Buffer = &Path.Buffer[i + 1];
|
||
}
|
||
|
||
//
|
||
// And return to our caller
|
||
//
|
||
|
||
return;
|
||
}
|
||
|
||
|
||
BOOLEAN
|
||
FsRtlDoesDbcsContainWildCards (
|
||
IN PANSI_STRING Name
|
||
)
|
||
|
||
/*++
|
||
|
||
Routine Description:
|
||
|
||
This routine checks if the input Dbcs name contains any wild card
|
||
characters (i.e., *, ?, ANSI_DOS_STAR, or ANSI_DOS_QM).
|
||
|
||
Arguments:
|
||
|
||
Name - Supplies the name to examine
|
||
|
||
Return Value:
|
||
|
||
BOOLEAN - TRUE if the input name contains any wildcard characters and
|
||
FALSE otherwise.
|
||
|
||
--*/
|
||
|
||
{
|
||
CLONG i;
|
||
|
||
PAGED_CODE();
|
||
|
||
//
|
||
// Check each character in the name to see if it's a wildcard
|
||
// character
|
||
//
|
||
|
||
for (i = 0; i < Name->Length; i += 1) {
|
||
|
||
//
|
||
// check for dbcs character because we'll just skip over those
|
||
//
|
||
|
||
if (FsRtlIsLeadDbcsCharacter( Name->Buffer[i] )) {
|
||
|
||
i += 1;
|
||
|
||
//
|
||
// else check for a wild card character
|
||
//
|
||
|
||
} else if (FsRtlIsAnsiCharacterWild( Name->Buffer[i] )) {
|
||
|
||
//
|
||
// Tell caller that this name contains wild cards
|
||
//
|
||
|
||
return TRUE;
|
||
}
|
||
}
|
||
|
||
//
|
||
// No wildcard characters were found, so return to our caller
|
||
//
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
#define GetDbcs(BUF,OFFSET,DBCS_CHAR,LENGTH) { \
|
||
if (FsRtlIsLeadDbcsCharacter( (BUF)[(OFFSET)] )) { \
|
||
*(DBCS_CHAR) = (WCHAR)((BUF)[(OFFSET)] + \
|
||
0x100 * (BUF)[(OFFSET) + 1]); \
|
||
*(LENGTH) = 2; \
|
||
} else { \
|
||
*(DBCS_CHAR) = (WCHAR)(BUF)[(OFFSET)]; \
|
||
*(LENGTH) = 1; \
|
||
} \
|
||
}
|
||
|
||
#define MATCHES_ARRAY_SIZE 16
|
||
|
||
BOOLEAN
|
||
FsRtlIsDbcsInExpression (
|
||
IN PANSI_STRING Expression,
|
||
IN PANSI_STRING Name
|
||
)
|
||
|
||
/*++
|
||
|
||
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
|
||
finite automatons below. Note that ~* and ~? are DOS_STAR and DOS_QM.
|
||
|
||
|
||
~* is DOS_STAR, ~? is DOS_QM, and ~. is DOS_DOT
|
||
|
||
|
||
S
|
||
<-----<
|
||
X | | e Y
|
||
X * Y == (0)----->-(1)->-----(2)-----(3)
|
||
|
||
|
||
S-.
|
||
<-----<
|
||
X | | e Y
|
||
X ~* Y == (0)----->-(1)->-----(2)-----(3)
|
||
|
||
|
||
|
||
X S S Y
|
||
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
|
||
|
||
Name - Supplies the input name to check for.
|
||
|
||
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;
|
||
USHORT Length;
|
||
|
||
ULONG SrcCount;
|
||
ULONG DestCount;
|
||
ULONG PreviousDestCount;
|
||
ULONG MatchesCount;
|
||
|
||
WCHAR NameChar, 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, "FsRtlIsDbcsInExpression\n", 0);
|
||
DebugTrace( 0, Dbg, " Expression = %Z\n", Expression );
|
||
DebugTrace( 0, Dbg, " Name = %Z\n", Name );
|
||
|
||
ASSERT( Name->Length != 0 );
|
||
ASSERT( Expression->Length != 0 );
|
||
|
||
//
|
||
// 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 == 1) && (Expression->Buffer[0] == '*')) {
|
||
|
||
return TRUE;
|
||
}
|
||
|
||
ASSERT( FsRtlDoesDbcsContainWildCards( Expression ) );
|
||
|
||
//
|
||
// 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] == '*') {
|
||
|
||
ANSI_STRING LocalExpression;
|
||
|
||
LocalExpression = *Expression;
|
||
|
||
LocalExpression.Buffer += 1;
|
||
LocalExpression.Length -= 1;
|
||
|
||
//
|
||
// Only special case an expression with a single *
|
||
//
|
||
|
||
if ( !FsRtlDoesDbcsContainWildCards( &LocalExpression ) ) {
|
||
|
||
ULONG StartingNameOffset;
|
||
|
||
if (Name->Length < (USHORT)(Expression->Length - 1)) {
|
||
|
||
return FALSE;
|
||
}
|
||
|
||
StartingNameOffset = Name->Length - LocalExpression.Length;
|
||
|
||
//
|
||
// FsRtlIsDbcsInExpression(): bug fix "expression[0] == *" case
|
||
//
|
||
// StatingNameOffset must not bisect DBCS characters.
|
||
//
|
||
|
||
if (NlsMbOemCodePageTag) {
|
||
|
||
ULONG i = 0;
|
||
|
||
while ( i < StartingNameOffset ) {
|
||
|
||
i += FsRtlIsLeadDbcsCharacter( Name->Buffer[i] ) ? 2 : 1;
|
||
}
|
||
|
||
if ( i > StartingNameOffset ) {
|
||
|
||
return FALSE;
|
||
}
|
||
}
|
||
|
||
//
|
||
// Do a simple memory compare if case sensitive, otherwise
|
||
// we have got to check this one character at a time.
|
||
//
|
||
|
||
return (BOOLEAN) RtlEqualMemory( LocalExpression.Buffer,
|
||
Name->Buffer + StartingNameOffset,
|
||
LocalExpression.Length );
|
||
}
|
||
}
|
||
|
||
//
|
||
// 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 ) {
|
||
|
||
GetDbcs( Name->Buffer, NameOffset, &NameChar, &Length );
|
||
NameOffset += Length;
|
||
|
||
} 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 ) {
|
||
|
||
//
|
||
// 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 += Length;
|
||
|
||
CurrentState = (USHORT)(ExprOffset * 2);
|
||
|
||
if ( ExprOffset == Expression->Length ) {
|
||
|
||
CurrentMatches[DestCount++] = MaxState;
|
||
break;
|
||
}
|
||
|
||
GetDbcs(Expression->Buffer, ExprOffset, &ExprChar, &Length);
|
||
|
||
ASSERT( !((ExprChar >= 'a') && (ExprChar <= '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) ) {
|
||
|
||
AuxBuffer = FsRtlpAllocatePool( PagedPool,
|
||
(Expression->Length+1) *
|
||
sizeof(USHORT)*2*2 );
|
||
|
||
RtlCopyMemory( AuxBuffer,
|
||
CurrentMatches,
|
||
MATCHES_ARRAY_SIZE * sizeof(USHORT) );
|
||
|
||
CurrentMatches = AuxBuffer;
|
||
|
||
RtlCopyMemory( AuxBuffer + (Expression->Length+1)*2,
|
||
PreviousMatches,
|
||
MATCHES_ARRAY_SIZE * sizeof(USHORT) );
|
||
|
||
PreviousMatches = AuxBuffer + (Expression->Length+1)*2;
|
||
|
||
}
|
||
|
||
//
|
||
// * matches any character zero or more times.
|
||
//
|
||
|
||
if (ExprChar == '*') {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
CurrentMatches[DestCount++] = CurrentState + 1;
|
||
continue;
|
||
}
|
||
|
||
//
|
||
// DOS_STAR matches any character except . zero or more times.
|
||
//
|
||
|
||
if (ExprChar == ANSI_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 == '.') ) {
|
||
|
||
WCHAR NameChar;
|
||
USHORT Offset;
|
||
USHORT Length;
|
||
|
||
for ( Offset = NameOffset;
|
||
Offset < Name->Length;
|
||
Offset += Length ) {
|
||
|
||
GetDbcs( Name->Buffer, Offset, &NameChar, &Length );
|
||
|
||
if (NameChar == '.') {
|
||
|
||
ICanEatADot = TRUE;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (NameFinished || (NameChar != '.') || ICanEatADot) {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
CurrentMatches[DestCount++] = CurrentState + 1;
|
||
continue;
|
||
|
||
} else {
|
||
|
||
//
|
||
// We are at a period. We can only match zero
|
||
// characters (ie. the epsilon transition).
|
||
//
|
||
|
||
CurrentMatches[DestCount++] = CurrentState + 1;
|
||
continue;
|
||
}
|
||
}
|
||
|
||
//
|
||
// The following expreesion characters all match by consuming
|
||
// a character, thus force the expression, and thus state
|
||
// forward.
|
||
//
|
||
|
||
CurrentState += (USHORT)(Length * 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 == ANSI_DOS_QM ) {
|
||
|
||
if ( NameFinished || (NameChar == '.') ) {
|
||
|
||
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 == '.') {
|
||
|
||
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 == '?') {
|
||
|
||
CurrentMatches[DestCount++] = CurrentState;
|
||
break;
|
||
}
|
||
|
||
//
|
||
// Finally, check if the expression char matches the name char
|
||
//
|
||
|
||
if (ExprChar == 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);
|
||
}
|
||
|