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
37 namespace WebCore {
38
39 const char DOMFilePath::separator = '/';
40 const char DOMFilePath::root[] = "/";
41
append(const String & base,const String & components)42 String DOMFilePath::append(const String& base, const String& components)
43 {
44 return ensureDirectoryPath(base) + components;
45 }
46
ensureDirectoryPath(const String & path)47 String DOMFilePath::ensureDirectoryPath(const String& path)
48 {
49 if (!DOMFilePath::endsWithSeparator(path)) {
50 String newPath = path;
51 newPath.append(DOMFilePath::separator);
52 return newPath;
53 }
54 return path;
55 }
56
getName(const String & path)57 String DOMFilePath::getName(const String& path)
58 {
59 int index = path.reverseFind(DOMFilePath::separator);
60 if (index != -1)
61 return path.substring(index + 1);
62 return path;
63 }
64
getDirectory(const String & path)65 String DOMFilePath::getDirectory(const String& path)
66 {
67 int index = path.reverseFind(DOMFilePath::separator);
68 if (!index)
69 return DOMFilePath::root;
70 if (index != -1)
71 return path.substring(0, index);
72 return ".";
73 }
74
isParentOf(const String & parent,const String & mayBeChild)75 bool DOMFilePath::isParentOf(const String& parent, const String& mayBeChild)
76 {
77 ASSERT(DOMFilePath::isAbsolute(parent));
78 ASSERT(DOMFilePath::isAbsolute(mayBeChild));
79 if (parent == DOMFilePath::root && mayBeChild != DOMFilePath::root)
80 return true;
81 if (parent.length() >= mayBeChild.length() || !mayBeChild.startsWith(parent, false))
82 return false;
83 if (mayBeChild[parent.length()] != DOMFilePath::separator)
84 return false;
85 return true;
86 }
87
removeExtraParentReferences(const String & path)88 String DOMFilePath::removeExtraParentReferences(const String& path)
89 {
90 ASSERT(DOMFilePath::isAbsolute(path));
91 Vector<String> components;
92 Vector<String> canonicalized;
93 path.split(DOMFilePath::separator, components);
94 for (size_t i = 0; i < components.size(); ++i) {
95 if (components[i] == ".")
96 continue;
97 if (components[i] == "..") {
98 if (canonicalized.size() > 0)
99 canonicalized.removeLast();
100 continue;
101 }
102 canonicalized.append(components[i]);
103 }
104 if (canonicalized.isEmpty())
105 return DOMFilePath::root;
106 String result;
107 for (size_t i = 0; i < canonicalized.size(); ++i) {
108 result.append(DOMFilePath::separator);
109 result.append(canonicalized[i]);
110 }
111 return result;
112 }
113
isValidPath(const String & path)114 bool DOMFilePath::isValidPath(const String& path)
115 {
116 if (path.isEmpty() || path == DOMFilePath::root)
117 return true;
118
119 // Embedded NULs are not allowed.
120 if (path.find(static_cast<UChar>(0)) != WTF::kNotFound)
121 return false;
122
123 // While not [yet] restricted by the spec, '\\' complicates implementation for Chromium.
124 if (path.find('\\') != WTF::kNotFound)
125 return false;
126
127 // This method is only called on fully-evaluated absolute paths. Any sign of ".." or "." is likely an attempt to break out of the sandbox.
128 Vector<String> components;
129 path.split(DOMFilePath::separator, components);
130 for (size_t i = 0; i < components.size(); ++i) {
131 if (components[i] == ".")
132 return false;
133 if (components[i] == "..")
134 return false;
135 }
136 return true;
137 }
138
isValidName(const String & name)139 bool DOMFilePath::isValidName(const String& name)
140 {
141 if (name.isEmpty())
142 return true;
143 // '/' is not allowed in name.
144 if (name.contains('/'))
145 return false;
146 return isValidPath(name);
147 }
148
149 } // namespace WebCore
150