1 /*
2 * Copyright (C) 2010 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32 #include "modules/filesystem/DOMFilePath.h"
33
34 #include "wtf/Vector.h"
35 #include "wtf/text/CString.h"
36 #include "wtf/text/StringBuilder.h"
37
38 namespace blink {
39
40 const char DOMFilePath::separator = '/';
41 const char DOMFilePath::root[] = "/";
42
append(const String & base,const String & components)43 String DOMFilePath::append(const String& base, const String& components)
44 {
45 return ensureDirectoryPath(base) + components;
46 }
47
ensureDirectoryPath(const String & path)48 String DOMFilePath::ensureDirectoryPath(const String& path)
49 {
50 if (!DOMFilePath::endsWithSeparator(path))
51 return path + DOMFilePath::separator;
52 return path;
53 }
54
getName(const String & path)55 String DOMFilePath::getName(const String& path)
56 {
57 int index = path.reverseFind(DOMFilePath::separator);
58 if (index != -1)
59 return path.substring(index + 1);
60 return path;
61 }
62
getDirectory(const String & path)63 String DOMFilePath::getDirectory(const String& path)
64 {
65 int index = path.reverseFind(DOMFilePath::separator);
66 if (!index)
67 return DOMFilePath::root;
68 if (index != -1)
69 return path.substring(0, index);
70 return ".";
71 }
72
isParentOf(const String & parent,const String & mayBeChild)73 bool DOMFilePath::isParentOf(const String& parent, const String& mayBeChild)
74 {
75 ASSERT(DOMFilePath::isAbsolute(parent));
76 ASSERT(DOMFilePath::isAbsolute(mayBeChild));
77 if (parent == DOMFilePath::root && mayBeChild != DOMFilePath::root)
78 return true;
79 if (parent.length() >= mayBeChild.length() || !mayBeChild.startsWith(parent, false))
80 return false;
81 if (mayBeChild[parent.length()] != DOMFilePath::separator)
82 return false;
83 return true;
84 }
85
removeExtraParentReferences(const String & path)86 String DOMFilePath::removeExtraParentReferences(const String& path)
87 {
88 ASSERT(DOMFilePath::isAbsolute(path));
89 Vector<String> components;
90 Vector<String> canonicalized;
91 path.split(DOMFilePath::separator, components);
92 for (size_t i = 0; i < components.size(); ++i) {
93 if (components[i] == ".")
94 continue;
95 if (components[i] == "..") {
96 if (canonicalized.size() > 0)
97 canonicalized.removeLast();
98 continue;
99 }
100 canonicalized.append(components[i]);
101 }
102 if (canonicalized.isEmpty())
103 return DOMFilePath::root;
104 StringBuilder result;
105 for (size_t i = 0; i < canonicalized.size(); ++i) {
106 result.append(DOMFilePath::separator);
107 result.append(canonicalized[i]);
108 }
109 return result.toString();
110 }
111
isValidPath(const String & path)112 bool DOMFilePath::isValidPath(const String& path)
113 {
114 if (path.isEmpty() || path == DOMFilePath::root)
115 return true;
116
117 // Embedded NULs are not allowed.
118 if (path.find(static_cast<UChar>(0)) != WTF::kNotFound)
119 return false;
120
121 // While not [yet] restricted by the spec, '\\' complicates implementation for Chromium.
122 if (path.find('\\') != WTF::kNotFound)
123 return false;
124
125 // This method is only called on fully-evaluated absolute paths. Any sign of ".." or "." is likely an attempt to break out of the sandbox.
126 Vector<String> components;
127 path.split(DOMFilePath::separator, components);
128 for (size_t i = 0; i < components.size(); ++i) {
129 if (components[i] == ".")
130 return false;
131 if (components[i] == "..")
132 return false;
133 }
134 return true;
135 }
136
isValidName(const String & name)137 bool DOMFilePath::isValidName(const String& name)
138 {
139 if (name.isEmpty())
140 return true;
141 // '/' is not allowed in name.
142 if (name.contains('/'))
143 return false;
144 return isValidPath(name);
145 }
146
147 } // namespace blink
148