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 "DOMFilePath.h"
33
34#if ENABLE(FILE_SYSTEM)
35
36#include "RegularExpression.h"
37#include <wtf/Vector.h>
38#include <wtf/text/CString.h>
39
40namespace WebCore {
41
42const char DOMFilePath::separator = '/';
43const char DOMFilePath::root[] = "/";
44
45String DOMFilePath::append(const String& base, const String& components)
46{
47    return ensureDirectoryPath(base) + components;
48}
49
50String DOMFilePath::ensureDirectoryPath(const String& path)
51{
52    if (!DOMFilePath::endsWithSeparator(path)) {
53        String newPath = path;
54        newPath.append(DOMFilePath::separator);
55        return newPath;
56    }
57    return path;
58}
59
60String DOMFilePath::getName(const String& path)
61{
62    int index = path.reverseFind(DOMFilePath::separator);
63    if (index != -1)
64        return path.substring(index + 1);
65    return path;
66}
67
68String DOMFilePath::getDirectory(const String& path)
69{
70    int index = path.reverseFind(DOMFilePath::separator);
71    if (index == 0)
72        return DOMFilePath::root;
73    if (index != -1)
74        return path.substring(0, index);
75    return ".";
76}
77
78bool DOMFilePath::isParentOf(const String& parent, const String& mayBeChild)
79{
80    ASSERT(DOMFilePath::isAbsolute(parent));
81    ASSERT(DOMFilePath::isAbsolute(mayBeChild));
82    if (parent == DOMFilePath::root && mayBeChild != DOMFilePath::root)
83        return true;
84    if (parent.length() >= mayBeChild.length() || !mayBeChild.startsWith(parent, false))
85        return false;
86    if (mayBeChild[parent.length()] != DOMFilePath::separator)
87        return false;
88    return true;
89}
90
91String DOMFilePath::removeExtraParentReferences(const String& path)
92{
93    ASSERT(DOMFilePath::isAbsolute(path));
94    Vector<String> components;
95    Vector<String> canonicalized;
96    path.split(DOMFilePath::separator, components);
97    for (size_t i = 0; i < components.size(); ++i) {
98        if (components[i] == ".")
99            continue;
100        if (components[i] == "..") {
101            if (canonicalized.size() > 0)
102                canonicalized.removeLast();
103            continue;
104        }
105        canonicalized.append(components[i]);
106    }
107    if (canonicalized.isEmpty())
108        return DOMFilePath::root;
109    String result;
110    for (size_t i = 0; i < canonicalized.size(); ++i) {
111        result.append(DOMFilePath::separator);
112        result.append(canonicalized[i]);
113    }
114    return result;
115}
116
117// Check the naming restrictions defined in FileSystem API 8.3.
118// http://dev.w3.org/2009/dap/file-system/file-dir-sys.html#naming-restrictions
119bool DOMFilePath::isValidPath(const String& path)
120{
121    if (path.isEmpty() || path == DOMFilePath::root)
122        return true;
123
124    // Chars 0-31 in UTF-8 prepresentation are not allowed.
125    for (size_t i = 0; i < path.length(); ++i)
126        if (path[i] < 32)
127            return false;
128
129    // Unallowed names.
130    DEFINE_STATIC_LOCAL(RegularExpression, unallowedNamesRegExp1, ("(/|^)(CON|PRN|AUX|NUL)([\\./]|$)", TextCaseInsensitive));
131    DEFINE_STATIC_LOCAL(RegularExpression, unallowedNamesRegExp2, ("(/|^)(COM|LPT)[1-9]([\\./]|$)", TextCaseInsensitive));
132
133    if (unallowedNamesRegExp1.match(path) >= 0)
134        return false;
135    if (unallowedNamesRegExp2.match(path) >= 0)
136        return false;
137
138    // Names must not end with period or whitespace.
139    DEFINE_STATIC_LOCAL(RegularExpression, endingRegExp, ("[\\.\\s](/|$)", TextCaseInsensitive));
140
141    if (endingRegExp.match(path) >= 0)
142        return false;
143
144    // Unallowed chars: '\', '<', '>', ':', '?', '*', '"', '|'
145    // (We don't check '/' here as this method takes paths as its argument.)
146    DEFINE_STATIC_LOCAL(RegularExpression, unallowedCharsRegExp, ("[\\\\<>:\\?\\*\"|]", TextCaseInsensitive));
147
148    if (unallowedCharsRegExp.match(path) >= 0)
149        return false;
150
151    return true;
152}
153
154bool DOMFilePath::isValidName(const String& name)
155{
156    if (name.isEmpty())
157        return true;
158    // '/' is not allowed in name.
159    if (name.contains('/'))
160        return false;
161    return isValidPath(name);
162}
163
164} // namespace WebCore
165
166#endif // ENABLE(FILE_SYSTEM)
167