/src/edk2/MdeModulePkg/Universal/Disk/UdfDxe/FileName.c

Source
/** @file
  Helper functions for mangling file names in UDF/ECMA-167 file systems.

  Copyright (C) 2014-2017 Paulo Alcantara <pcacjr@zytor.com>

  SPDX-License-Identifier: BSD-2-Clause-Patent
**/

#include "Udf.h"

/**
  Trim the leading and trailing spaces for a give Unicode string.

  @param[in]  String              The Unicode string to trim.

  @return  A pointer to the trimmed string.

**/
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;
}

/**
  Replace the content of a Unicode string with the content of another Unicode
  string.

  @param[in]  Destination         A pointer to a Unicode string.
  @param[in]  Source              A pointer to a Unicode string.

**/
VOID
ReplaceLeft (
  IN CHAR16        *Destination,
  IN CONST CHAR16  *Source
  )
{
  CONST CHAR16  *EndString;

  EndString = Source + StrLen (Source);
  while (Source <= EndString) {
    *Destination++ = *Source++;
  }
}

/**
  Remove one or more consecutive backslashes starting from the second character
  of a given Unicode string.

  @param[in]  String              A pointer to a Unicode string.

  @return  A pointer to the modified string.

**/
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'\\') {
    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 The mangled Filename.

**/
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 L'.':
          if (FileName - 1 >= FileNameSavedPointer && *(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 (TempFileName - 1 >= FileNameSavedPointer && *(TempFileName - 1) == L'\\') {
              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;
}

Coverage Report

Created: 2026-03-28 06:40

Line	Count	Source
1		/** @file
2		Helper functions for mangling file names in UDF/ECMA-167 file systems.
3
4		Copyright (C) 2014-2017 Paulo Alcantara <pcacjr@zytor.com>
5
6		SPDX-License-Identifier: BSD-2-Clause-Patent
7		**/
8
9		#include "Udf.h"
10
11		/**
12		Trim the leading and trailing spaces for a give Unicode string.
13
14		@param[in] String The Unicode string to trim.
15
16		@return A pointer to the trimmed string.
17
18		**/
19		CHAR16 *
20		TrimString (
21		IN CHAR16 *String
22		)
23	408	{
24	408	CHAR16 *TempString;
25
26	665	for ( ; String != L'\0' && String == L' '; String++) {
27	257	}
28
29	408	TempString = String + StrLen (String) - 1;
30	466	while ((TempString >= String) && (*TempString == L' ')) {
31	58	TempString--;
32	58	}
33
34	408	*(TempString + 1) = L'\0';
35
36	408	return String;
37	408	}
38
39		/**
40		Replace the content of a Unicode string with the content of another Unicode
41		string.
42
43		@param[in] Destination A pointer to a Unicode string.
44		@param[in] Source A pointer to a Unicode string.
45
46		**/
47		VOID
48		ReplaceLeft (
49		IN CHAR16 *Destination,
50		IN CONST CHAR16 *Source
51		)
52	2.21k	{
53	2.21k	CONST CHAR16 *EndString;
54
55	2.21k	EndString = Source + StrLen (Source);
56	906k	while (Source <= EndString) {
57	904k	Destination++ = Source++;
58	904k	}
59	2.21k	}
60
61		/**
62		Remove one or more consecutive backslashes starting from the second character
63		of a given Unicode string.
64
65		@param[in] String A pointer to a Unicode string.
66
67		@return A pointer to the modified string.
68
69		**/
70		CHAR16 *
71		ExcludeTrailingBackslashes (
72		IN CHAR16 *String
73		)
74	2.70k	{
75	2.70k	CHAR16 *TempString;
76
77	2.70k	switch (*(String + 1)) {
78	956	case L'\\':
79	956	break;
80	22	case L'\0':
81	1.75k	default:
82	1.75k	String++;
83	1.75k	goto Exit;
84	2.70k	}
85
86	956	TempString = String;
87	3.60k	while (*TempString == L'\\') {
88	2.64k	TempString++;
89	2.64k	}
90
91	956	if (TempString - 1 > String) {
92	956	ReplaceLeft (String + 1, TempString);
93	956	}
94
95	956	String++;
96
97	2.70k	Exit:
98	2.70k	return String;
99	956	}
100
101		/**
102		Mangle a filename by cutting off trailing whitespaces, "\\", "." and "..".
103
104		@param[in] FileName Filename.
105
106		@retval The mangled Filename.
107
108		**/
109		CHAR16 *
110		MangleFileName (
111		IN CHAR16 *FileName
112		)
113	413	{
114	413	CHAR16 *FileNameSavedPointer;
115	413	CHAR16 *TempFileName;
116	413	UINTN BackslashesNo;
117
118	413	if ((FileName == NULL) \|\| (*FileName == L'\0')) {
119	5	FileName = NULL;
120	5	goto Exit;
121	5	}
122
123	408	FileName = TrimString (FileName);
124	408	if (*FileName == L'\0') {
125	8	goto Exit;
126	8	}
127
128	400	if ((StrLen (FileName) > 1) && (FileName[StrLen (FileName) - 1] == L'\\')) {
129	40	FileName[StrLen (FileName) - 1] = L'\0';
130	40	}
131
132	400	FileNameSavedPointer = FileName;
133
134	400	if (FileName[0] == L'.') {
135	127	if (FileName[1] == L'.') {
136	29	if (FileName[2] == L'\0') {
137	1	goto Exit;
138	28	} else {
139	28	FileName += 2;
140	28	}
141	98	} else if (FileName[1] == L'\0') {
142	1	goto Exit;
143	1	}
144	127	}
145
146	26.0k	while (*FileName != L'\0') {
147	25.6k	if (*FileName == L'\\') {
148	1.45k	FileName = ExcludeTrailingBackslashes (FileName);
149	24.2k	} else if (*FileName == L'.') {
150	3.41k	switch (*(FileName + 1)) {
151	29	case L'\0':
152	29	*FileName = L'\0';
153	29	break;
154	781	case L'\\':
155	781	TempFileName = FileName + 1;
156	781	TempFileName = ExcludeTrailingBackslashes (TempFileName);
157	781	ReplaceLeft (FileName, TempFileName);
158	781	break;
159	1.46k	case L'.':
160	1.46k	if (FileName - 1 >= FileNameSavedPointer && *(FileName - 1) != L'\\' &&
161	1.22k	(FileName + 2) != L'\\' && (FileName + 2) != L'\0')
162	879	{
163	879	FileName++;
164	879	continue;
165	879	}
166
167	588	BackslashesNo = 0;
168	588	TempFileName = FileName - 1;
169	9.00k	while (TempFileName >= FileNameSavedPointer) {
170	8.91k	if (*TempFileName == L'\\') {
171	1.05k	if (++BackslashesNo == 2) {
172	498	break;
173	498	}
174	1.05k	}
175
176	8.41k	TempFileName--;
177	8.41k	}
178
179	588	TempFileName++;
180
181	588	if ((TempFileName == L'.') && ((TempFileName + 1) == L'.')) {
182	88	FileName += 2;
183	500	} else {
184	500	if (TempFileName - 1 >= FileNameSavedPointer && *(TempFileName - 1) == L'\\') {
185	476	ReplaceLeft (TempFileName, FileName + 3);
186	476	if (*(TempFileName - 1) == L'\\') {
187	476	FileName = TempFileName;
188	476	ExcludeTrailingBackslashes (TempFileName - 1);
189	476	TempFileName = FileName;
190	476	}
191	476	} else {
192	24	*TempFileName = L'\0';
193	24	}
194
195	500	FileName = TempFileName;
196	500	}
197
198	588	break;
199	1.13k	default:
200	1.13k	FileName++;
201	3.41k	}
202	20.8k	} else {
203	20.8k	FileName++;
204	20.8k	}
205	25.6k	}
206
207	398	FileName = FileNameSavedPointer;
208	398	if ((StrLen (FileName) > 1) && (FileName[StrLen (FileName) - 1] == L'\\')) {
209	39	FileName[StrLen (FileName) - 1] = L'\0';
210	39	}
211
212	413	Exit:
213	413	return FileName;
214	398	}