MdeModulePkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / MdeModulePkg / Universal / Disk / UdfDxe / FileName.c

/** @file\r
  Helper functions for mangling file names in UDF/ECMA-167 file systems.\r
\r
  Copyright (C) 2014-2017 Paulo Alcantara <pcacjr@zytor.com>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include "Udf.h"\r
\r
/**\r
  Trim the leading and trailing spaces for a give Unicode string.\r
\r
  @param[in]  String              The Unicode string to trim.\r
\r
  @return  A pointer to the trimmed string.\r
\r
**/\r
CHAR16 *\r
TrimString (\r
  IN CHAR16    *String\r
  )\r
{\r
  CHAR16       *TempString;\r
\r
  for ( ; *String != L'\0' && *String == L' '; String++) {\r
    ;\r
  }\r
\r
  TempString = String + StrLen (String) - 1;\r
  while ((TempString >= String) && (*TempString == L' ')) {\r
    TempString--;\r
  }\r
\r
  *(TempString + 1) = L'\0';\r
\r
  return String;\r
}\r
\r
/**\r
  Replace the content of a Unicode string with the content of another Unicode\r
  string.\r
\r
  @param[in]  Destination         A pointer to a Unicode string.\r
  @param[in]  Source              A pointer to a Unicode string.\r
\r
**/\r
VOID\r
ReplaceLeft (\r
  IN CHAR16         *Destination,\r
  IN CONST CHAR16   *Source\r
  )\r
{\r
  CONST CHAR16      *EndString;\r
\r
  EndString = Source + StrLen (Source);\r
  while (Source <= EndString) {\r
    *Destination++ = *Source++;\r
  }\r
}\r
\r
/**\r
  Remove one or more consecutive backslashes starting from the second character\r
  of a given Unicode string.\r
\r
  @param[in]  String              A pointer to a Unicode string.\r
\r
  @return  A pointer to the modified string.\r
\r
**/\r
CHAR16 *\r
ExcludeTrailingBackslashes (\r
  IN CHAR16                    *String\r
  )\r
{\r
  CHAR16                       *TempString;\r
\r
  switch (*(String + 1)) {\r
  case L'\\':\r
    break;\r
  case L'\0':\r
  default:\r
    String++;\r
    goto Exit;\r
  }\r
\r
  TempString = String;\r
  while (*TempString != L'\0' && *TempString == L'\\') {\r
    TempString++;\r
  }\r
\r
  if (TempString - 1 > String) {\r
    ReplaceLeft (String + 1, TempString);\r
  }\r
\r
  String++;\r
\r
Exit:\r
  return String;\r
}\r
\r
/**\r
  Mangle a filename by cutting off trailing whitespaces, "\\", "." and "..".\r
\r
  @param[in] FileName Filename.\r
\r
  @retval The mangled Filename.\r
\r
**/\r
CHAR16 *\r
MangleFileName (\r
  IN CHAR16        *FileName\r
  )\r
{\r
  CHAR16           *FileNameSavedPointer;\r
  CHAR16           *TempFileName;\r
  UINTN            BackslashesNo;\r
\r
  if (FileName == NULL || *FileName == L'\0') {\r
    FileName = NULL;\r
    goto Exit;\r
  }\r
\r
  FileName = TrimString (FileName);\r
  if (*FileName == L'\0') {\r
    goto Exit;\r
  }\r
\r
  if ((StrLen (FileName) > 1) && (FileName[StrLen (FileName) - 1] == L'\\')) {\r
    FileName[StrLen (FileName) - 1] = L'\0';\r
  }\r
\r
  FileNameSavedPointer = FileName;\r
\r
  if (FileName[0] == L'.') {\r
    if (FileName[1] == L'.') {\r
      if (FileName[2] == L'\0') {\r
        goto Exit;\r
      } else {\r
        FileName += 2;\r
      }\r
    } else if (FileName[1] == L'\0') {\r
      goto Exit;\r
    }\r
  }\r
\r
  while (*FileName != L'\0') {\r
    if (*FileName == L'\\') {\r
      FileName = ExcludeTrailingBackslashes (FileName);\r
    } else if (*FileName == L'.') {\r
      switch (*(FileName + 1)) {\r
      case L'\0':\r
        *FileName = L'\0';\r
        break;\r
      case L'\\':\r
        TempFileName = FileName + 1;\r
        TempFileName = ExcludeTrailingBackslashes (TempFileName);\r
        ReplaceLeft (FileName, TempFileName);\r
        break;\r
      case '.':\r
        if ((*(FileName - 1) != L'\\') && ((*(FileName + 2) != L'\\') ||\r
                                           (*(FileName + 2) != L'\0'))) {\r
          FileName++;\r
          continue;\r
        }\r
\r
        BackslashesNo = 0;\r
        TempFileName = FileName - 1;\r
        while (TempFileName >= FileNameSavedPointer) {\r
          if (*TempFileName == L'\\') {\r
            if (++BackslashesNo == 2) {\r
              break;\r
            }\r
          }\r
\r
          TempFileName--;\r
        }\r
\r
        TempFileName++;\r
\r
        if ((*TempFileName == L'.') && (*(TempFileName + 1) == L'.')) {\r
          FileName += 2;\r
        } else {\r
          if (*(FileName + 2) != L'\0') {\r
            ReplaceLeft (TempFileName, FileName + 3);\r
            if (*(TempFileName - 1) == L'\\') {\r
              FileName = TempFileName;\r
              ExcludeTrailingBackslashes (TempFileName - 1);\r
              TempFileName = FileName;\r
            }\r
          } else {\r
            *TempFileName = L'\0';\r
          }\r
\r
          FileName = TempFileName;\r
        }\r
\r
        break;\r
      default:\r
        FileName++;\r
      }\r
    } else {\r
      FileName++;\r
    }\r
  }\r
\r
  FileName = FileNameSavedPointer;\r
  if ((StrLen (FileName) > 1) && (FileName [StrLen (FileName) - 1] == L'\\')) {\r
    FileName [StrLen (FileName) - 1] = L'\0';\r
  }\r
\r
Exit:\r
  return FileName;\r
}\r