windows-nt/Source/XPSP1/NT/windows/appcompat/shims/lib/win9xpath.cpp
2020-09-26 16:20:57 +08:00

417 lines
12 KiB
C++

/*++
Copyright (c) 2000-2001 Microsoft Corporation
Module Name:
Win9xPath.cpp
Abstract:
Munge a path the same was as Win9x.
Much of this code was copied from Win9x:
\\redrum\slm\proj\win\src\CORE\win32\KERNEL\dirutil.c
\\redrum\slm\proj\win\src\CORE\win32\KERNEL\fileopcc.c
Path changes:
1. Translate all / to \
2. Remove all . and .. from the path, also removes some spaces
(This is really bad Win9x code)
3. Remove all spaces before a \, except spaces following a .
( "abc \xyz" -> "abc\xyz" or ". \xyz" -> ". \xyz")
Notes:
None
History:
10/05/2000 robkenny Created
08/14/2001 robkenny Moved code inside the ShimLib namespace.
--*/
#include "Win9xPath.h"
#include "ShimLib.h"
namespace ShimLib
{
#define WHACK L'\\'
#define SPACE L' '
#define DOT L'.'
#define QUESTION L'.'
#define EOS L'\0'
#define chNetIni L'\\'
#define chDirSep L'\\'
#define chDirSep2 L'/'
#define chRelDir L'.'
#define IsWhackWhack( lpstr ) (lpstr[0] == WHACK && lpstr[1] == WHACK)
#define IsWhackWhackDotWhack( lpstr ) (lpstr[0] == WHACK && lpstr[1] == WHACK && lpstr[2] == DOT && lpstr[3] == WHACK)
#define IsWhackWhackQuestionWhack( lpstr ) (lpstr[0] == WHACK && lpstr[1] == WHACK && lpstr[2] == QUESTION && lpstr[3] == WHACK)
#define CopySz wcscpy // Must be safe for overlapping strings
/*** PchGetNetDir - Validates a net drive spcification and returns
** a pointer to directory portion.
**
** Synopsis
** WCHAR * = PchGetNetDir (pchNetName)
**
** Input:
** pchNetName - pointer to a string previously validated as
** the start of a net name (begins with \\)
**
** Output:
** returns pointer to the start of the directory portion of a net path
**
** Errors:
** returns NULL if the net name is invalid
**
** Description:
** This function takes a name starting with \\ and confirms that
** it has one following \. It returns the position of the directory
** portion. For the string
**
** \\server\share[\path[\]]
**
** it returns
**
** [\path[\]]
*/
const WCHAR * PchGetNetDir (const WCHAR * pchNetName)
{
register const WCHAR * pch = pchNetName;
// Skip starting slashes
pch +=2;
// Skip to first backslash
for (;*pch != chNetIni; pch++) {
if (*pch == EOS) {
// No code required.
return (NULL);
}
}
pch++; // skip past 1st backslash
// Skip to second backslash
for (;(*pch != chDirSep) && (*pch != chDirSep2); pch++) {
if (*pch == EOS) {
// ok if share with no following \path
return ((*(pch-1)==chNetIni) ? NULL : pch);
}
}
return (pch);
}
/*** DwRemoveDots - Remove any dots from a path name
**
** Synopsis
** DWORD DwRemoveDots (pchPath)
**
** Input:
** pchPath - A path string
**
**
** Output:
** returns the number of double dot levels removed from front
**
** Errors:
** returns dwInvalid if invalid path
**
** Description:
** Removes ..\ and .\ sequences from a path string. The path
** string should not include the root drive or net name portion.
** The return value of is the number of levels removed from the
** start of the string. Levels removed from inside the string
** will not be returned. For example:
**
** String Result Return
**
** ..\..\dir1 dir1 2
** dir1\..\dir2 dir2 0
** dir1\..\..\dir2 dir2 1
** .\dir1 dir1 0
** dir1\.\dir2 dir1\dir2 0
**
** A backslash at the start of the string will be ignored.
*/
DWORD DwRemoveDots (WCHAR * pchPath)
{
BOOL fInside = FALSE;
DWORD cLevel = 0;
DWORD cBackup;
register WCHAR * pchR;
register WCHAR * pchL;
// Check for invalid characters
// if (!FFixPathChars(pchPath)) {
// // No code required.
// return dwInvalid;
// }
//
// Skip slashes
for (; *pchPath == chDirSep; pchPath++)
;
pchL = pchR = pchPath;
// Loop through handling each directory part
while (*pchR) {
// This part starts with dot. Is it one or more?
if (*pchR++ == chRelDir) {
for (cBackup = 0; *pchR == chRelDir; cBackup++, pchR++)
;
if (cBackup) {
// More than one dot. Back up the left pointer.
if ((*pchR != chDirSep) && (*pchR != EOS)) {
// we got a [.]+X (X != '\') might be an LFN
// process this as a name
goto name_processing;
}
// Doesn't advance for ending ..
for (; *pchR == chDirSep; pchR++)
;
if (fInside) {
for (; cBackup; cBackup--) {
if (pchL <= pchPath) {
cLevel += cBackup;
fInside = FALSE;
break;
}
// Remove the previous part
for (pchL -= 2; *pchL != chDirSep; pchL--) {
if (pchL <= pchPath) {
fInside = FALSE;
pchL--;
break;
}
}
pchL++;
}
} else {
cLevel += cBackup;
}
// Subtract ending backslash if not root
if ((*pchR == EOS) && (pchL != pchPath))
pchL--;
CopySz(pchL, pchR);
pchR = pchL;
} else {
// This part starts with one dot. Throw it away.
if (*pchR != chDirSep) {
// Special case "\." by converting it to ""
// unless it is a root, when it becomes "\".
if (*pchR == EOS) {
if (pchL == pchPath)
*(pchR-1) = EOS; // root
else
*(pchR-2) = EOS; // not root
return cLevel;
}
// we started with a '.' and then there was no '\'
// might be an LFN name
goto name_processing;
}
pchR++;
CopySz(pchL, pchR);
pchR = pchL;
}
} else {
name_processing:
// This part is a name. Skip it.
fInside = TRUE;
for (; TRUE; pchR++) {
if (*pchR == chDirSep) {
if (*(pchR-1) == chRelDir) {
// This name has one or more dots at the end.
// Remove the last dot (NT3.5 does this).
pchL = pchR-1;
CopySz(pchL, pchR);
pchR = pchL; // point to chDirSep again
}
for (; *pchR == chDirSep; pchR++)
;
break;
} else if (*pchR == EOS) {
// Remove trailing dots.
// NB Can't fall off the beginning since the first WCHAR
// of the current path element was not chRelDir.
for (; *(pchR-1) == chRelDir; pchR--)
;
// Overstore the first trailing dot, if there is one.
*pchR = EOS;
break;
}
}
pchL = pchR;
}
}
return cLevel;
}
// Get the Drive portion of this path,
// Either C: or \\server\disk format.
const WCHAR * GetDrivePortion(const WCHAR * uncorrected)
{
if (uncorrected && uncorrected[0])
{
// Look for DOS style
if (uncorrected[1] == ':')
{
uncorrected += 2;
}
// Look for UNC
else if (IsWhackWhack(uncorrected))
{
const WCHAR * pchDir = PchGetNetDir(uncorrected);
if (pchDir == NULL)
{
if (IsWhackWhackDotWhack(uncorrected) || IsWhackWhackQuestionWhack(uncorrected))
{
uncorrected += 4;
}
}
else
{
uncorrected = pchDir;
}
}
}
return uncorrected;
}
// Remove blank directory names "abc\ \def" -> "abc\def"
void RemovePreceedingBlanks(WCHAR * directoryPortion)
{
if (directoryPortion == NULL || directoryPortion[0] == 0)
{
return;
}
WCHAR * blank = wcschr(directoryPortion, SPACE);
while (blank != NULL)
{
// Find the end of the spaces
WCHAR * blankEnd = blank;
while (*blankEnd == SPACE && *blankEnd != WHACK)
{
++blankEnd;
}
// Do not remove spaces *after* a period
BOOL bPrevCharDot = (blank > directoryPortion) && (blank[-1] == DOT);
if (bPrevCharDot)
{
blank = blankEnd;
continue;
}
// If the the blank is a \ then we simply move the string down
if (*blankEnd == WHACK)
{
BOOL bPrevCharWhack = blank[-1] == WHACK;
// If the previous WCHAR is a \
// we remove the \ at the end of the spaces as well
if (bPrevCharWhack)
blankEnd += 1;
CopySz(blank, blankEnd);
// Note: we don't change the value of blank,
// since we moved all the data to it!
}
else
{
blank = blankEnd + 1;
}
// Keep on truckin'
blank = wcschr(blank, SPACE);
}
}
// Win9x performs some special process on path names,
// particularly they remove spaces before slashes.
WCHAR * W9xPathMassageW(const WCHAR * uncorrect)
{
if (uncorrect == NULL)
return NULL;
// Make a buffer large enough for the resulting string
WCHAR * correctBuffer = StringDuplicateW(uncorrect);
if (!correctBuffer)
return NULL;
// Convert all '/' to '\'
// Win9x allows //robkenny/d as a valid UNC name
for (WCHAR * whack = correctBuffer; *whack; ++whack)
{
if (*whack == chDirSep2)
*whack = chDirSep;
}
// We need to skip past the drive portion of the path
WCHAR * directoryPortion = (WCHAR *)GetDrivePortion(correctBuffer);
// Remove blank directory names "abc\ \def" -> "abc\def"
// These are remove entirely rather than just removing the spaces,
// because we could end up changing "\ \abc" -> "\\abc"
RemovePreceedingBlanks(directoryPortion);
// DwRemoveDots is used to remove all .\ and any ..\ in the middle of a path.
DWORD dwUpDirs = DwRemoveDots(directoryPortion);
if (dwUpDirs > 0)
{
// We need to add some ..\ to the front of the directoryPortion string
// This is sorta wierd, removing the dots and adding them back again.
// But the DwRemoveDots routine was copied strait from Win9x, and I
// didn't want to change it in any way, as to preserve all peculiarities.
// So we have to add back the leading parent directories that were removed.
DWORD dwLen = (dwUpDirs * 3) + wcslen(correctBuffer) + 1;
WCHAR * moreCorrectBuffer = (WCHAR*)malloc(dwLen * sizeof(WCHAR));
if (moreCorrectBuffer)
{
moreCorrectBuffer[0] = 0;
// Copy any drive portion
wcsncpy(moreCorrectBuffer, correctBuffer, directoryPortion - correctBuffer);
// add as many "..\" as were removed by DwRemoveDots
while (dwUpDirs-- > 0)
{
wcscat(moreCorrectBuffer, L"..\\");
}
// finally the remainder of the string
wcscat(moreCorrectBuffer, directoryPortion);
delete correctBuffer;
correctBuffer = moreCorrectBuffer;
}
}
return correctBuffer;
}
}; // end of namespace ShimLib