Files
system76-edk2/MdePkg/Library/BaseLib/FilePaths.c
Jim.Dailey@dell.com 7177be0bd8 MdePkg-BaseLib: Fix PathCleanUpDirectories() error involving "\..\.."
MdePkg-BaseLib: Fix PathCleanUpDirectories() error involving "\..\.."

The loop that removes "xxxx\..\" errs when multiple "\.." sequences are
in the path.  Before this change the code would modify a path like
"FS0:\efi\tools\..\.." to "FS0:\efi\\.." and then to "FS0:\efi\", but
the correct path is "FS0:\".

You can test the effect of this change in the shell by setting the
current directory to something like FS0:\efi\boot and then executing
the command "ls ..\..".  Before the change you will see the files in
the FS0:\efi directory; after the change, you will see the files in
the root directory of FS0:.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jim Dailey <jim_dailey@dell.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
2018-10-12 11:46:17 +08:00

122 lines
3.3 KiB
C

/** @file
Defines file-path manipulation functions.
Copyright (c) 2011 - 2017, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2018, Dell Technologies. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Library/BaseMemoryLib.h>
#include <Library/BaseLib.h>
/**
Removes the last directory or file entry in a path. For a path which is
like L"fs0:startup.nsh", it's converted to L"fs0:".
@param[in,out] Path A pointer to the path to modify.
@retval FALSE Nothing was found to remove.
@retval TRUE A directory or file was removed.
**/
BOOLEAN
EFIAPI
PathRemoveLastItem(
IN OUT CHAR16 *Path
)
{
CHAR16 *Walker;
CHAR16 *LastSlash;
//
// get directory name from path... ('chop' off extra)
//
for ( Walker = Path, LastSlash = NULL
; Walker != NULL && *Walker != CHAR_NULL
; Walker++
){
if (*Walker == L'\\' && *(Walker + 1) != CHAR_NULL) {
LastSlash = Walker+1;
} else if (*Walker == L':' && *(Walker + 1) != L'\\' && *(Walker + 1) != CHAR_NULL) {
LastSlash = Walker+1;
}
}
if (LastSlash != NULL) {
*LastSlash = CHAR_NULL;
return (TRUE);
}
return (FALSE);
}
/**
Function to clean up paths.
- Single periods in the path are removed.
- Double periods in the path are removed along with a single parent directory.
- Forward slashes L'/' are converted to backward slashes L'\'.
This will be done inline and the existing buffer may be larger than required
upon completion.
@param[in] Path The pointer to the string containing the path.
@return Returns Path, otherwise returns NULL to indicate that an error has occured.
**/
CHAR16*
EFIAPI
PathCleanUpDirectories(
IN CHAR16 *Path
)
{
CHAR16 *TempString;
if (Path == NULL) {
return NULL;
}
//
// Replace the '/' with '\'
//
for (TempString = Path; *TempString != CHAR_NULL; TempString++) {
if (*TempString == L'/') {
*TempString = L'\\';
}
}
//
// Remove all the "\.". E.g.: fs0:\abc\.\def\.
//
while ((TempString = StrStr (Path, L"\\.\\")) != NULL) {
CopyMem (TempString, TempString + 2, StrSize (TempString + 2));
}
if ((StrLen (Path) >= 2) && (StrCmp (Path + StrLen (Path) - 2, L"\\.") == 0)) {
Path[StrLen (Path) - 1] = CHAR_NULL;
}
//
// Remove all the "\..". E.g.: fs0:\abc\..\def\..
//
while (((TempString = StrStr(Path, L"\\..")) != NULL) &&
((*(TempString + 3) == L'\\') || (*(TempString + 3) == CHAR_NULL))
) {
*(TempString + 1) = CHAR_NULL;
PathRemoveLastItem(Path);
if (*(TempString + 3) != CHAR_NULL) {
CopyMem (Path + StrLen (Path), TempString + 4, StrSize (TempString + 4));
}
}
//
// Replace the "\\" with "\"
//
while ((TempString = StrStr (Path, L"\\\\")) != NULL) {
CopyMem (TempString, TempString + 1, StrSize (TempString + 1));
}
return Path;
}