MdeModulePkg: Initial UDF/ECMA-167 file system support

This patch introduces UDF file system support in EDK2. All block devices
that support BlockIo and DiskIo protocols and contain a valid UDF file
system - as specified by OSTA Universal Disk Format (revisions 1.02
through 2.60) - will be installed EFI_SIMPLE_FILE_SYSTEM_PROTOCOL to
provide access to underlying file system.

File system operations on regular, directory and symlink files are
supported.

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Paulo Alcantara <pcacjr@zytor.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

MdeModulePkg/Universal/Disk/UdfDxe/FileName.c

@@ -0,0 +1,195 @@
+/** @file
+  Helper functions for mangling file names in UDF/ECMA-167 file systems.
+
+  Copyright (C) 2014-2017 Paulo Alcantara <pcacjr@zytor.com>
+
+  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 "Udf.h"
+
+CHAR16 *
+TrimString (
+  IN CHAR16    *String
+  )
+{
+  CHAR16       *TempString;
+
+  for ( ; *String != L'\0' && *String == L' '; String++) {
+    ;
+  }
+
+  TempString = String + StrLen (String) - 1;
+  while ((TempString >= String) && (*TempString == L' ')) {
+    TempString--;
+  }
+
+  *(TempString + 1) = L'\0';
+
+  return String;
+}
+
+VOID
+ReplaceLeft (
+  IN CHAR16         *Destination,
+  IN CONST CHAR16   *Source
+  )
+{
+  CONST CHAR16      *EndString;
+
+  EndString = Source + StrLen (Source);
+  while (Source <= EndString) {
+    *Destination++ = *Source++;
+  }
+}
+
+CHAR16 *
+ExcludeTrailingBackslashes (
+  IN CHAR16                    *String
+  )
+{
+  CHAR16                       *TempString;
+
+  switch (*(String + 1)) {
+  case L'\\':
+    break;
+  case L'\0':
+  default:
+    String++;
+    goto Exit;
+  }
+
+  TempString = String;
+  while (*TempString != L'\0' && *TempString == L'\\') {
+    TempString++;
+  }
+
+  if (TempString - 1 > String) {
+    ReplaceLeft (String + 1, TempString);
+  }
+
+  String++;
+
+Exit:
+  return String;
+}
+
+/**
+  Mangle a filename by cutting off trailing whitespaces, "\\", "." and "..".
+
+  @param[in] FileName Filename.
+
+  @retval @p FileName Filename mangled.
+
+**/
+CHAR16 *
+MangleFileName (
+  IN CHAR16        *FileName
+  )
+{
+  CHAR16           *FileNameSavedPointer;
+  CHAR16           *TempFileName;
+  UINTN            BackslashesNo;
+
+  if (FileName == NULL || *FileName == L'\0') {
+    FileName = NULL;
+    goto Exit;
+  }
+
+  FileName = TrimString (FileName);
+  if (*FileName == L'\0') {
+    goto Exit;
+  }
+
+  if ((StrLen (FileName) > 1) && (FileName[StrLen (FileName) - 1] == L'\\')) {
+    FileName[StrLen (FileName) - 1] = L'\0';
+  }
+
+  FileNameSavedPointer = FileName;
+
+  if (FileName[0] == L'.') {
+    if (FileName[1] == L'.') {
+      if (FileName[2] == L'\0') {
+        goto Exit;
+      } else {
+        FileName += 2;
+      }
+    } else if (FileName[1] == L'\0') {
+      goto Exit;
+    }
+  }
+
+  while (*FileName != L'\0') {
+    if (*FileName == L'\\') {
+      FileName = ExcludeTrailingBackslashes (FileName);
+    } else if (*FileName == L'.') {
+      switch (*(FileName + 1)) {
+      case L'\0':
+        *FileName = L'\0';
+        break;
+      case L'\\':
+        TempFileName = FileName + 1;
+        TempFileName = ExcludeTrailingBackslashes (TempFileName);
+        ReplaceLeft (FileName, TempFileName);
+        break;
+      case '.':
+        if ((*(FileName - 1) != L'\\') && ((*(FileName + 2) != L'\\') ||
+                                           (*(FileName + 2) != L'\0'))) {
+          FileName++;
+          continue;
+        }
+
+        BackslashesNo = 0;
+        TempFileName = FileName - 1;
+        while (TempFileName >= FileNameSavedPointer) {
+          if (*TempFileName == L'\\') {
+            if (++BackslashesNo == 2) {
+              break;
+            }
+          }
+
+          TempFileName--;
+        }
+
+        TempFileName++;
+
+        if ((*TempFileName == L'.') && (*(TempFileName + 1) == L'.')) {
+          FileName += 2;
+        } else {
+          if (*(FileName + 2) != L'\0') {
+            ReplaceLeft (TempFileName, FileName + 3);
+            if (*(TempFileName - 1) == L'\\') {
+              FileName = TempFileName;
+              ExcludeTrailingBackslashes (TempFileName - 1);
+              TempFileName = FileName;
+            }
+          } else {
+            *TempFileName = L'\0';
+          }
+
+          FileName = TempFileName;
+        }
+
+        break;
+      default:
+        FileName++;
+      }
+    } else {
+      FileName++;
+    }
+  }
+
+  FileName = FileNameSavedPointer;
+  if ((StrLen (FileName) > 1) && (FileName [StrLen (FileName) - 1] == L'\\')) {
+    FileName [StrLen (FileName) - 1] = L'\0';
+  }
+
+Exit:
+  return FileName;
+}