1/*
2 * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package java.nio.file;
27
28import java.security.BasicPermission;
29
30/**
31 * The {@code Permission} class for link creation operations.
32 *
33 * <p> The following table provides a summary description of what the permission
34 * allows, and discusses the risks of granting code the permission.
35 *
36 * <table border=1 cellpadding=5
37 *        summary="Table shows permission target name, what the permission allows, and associated risks">
38 * <tr>
39 * <th>Permission Target Name</th>
40 * <th>What the Permission Allows</th>
41 * <th>Risks of Allowing this Permission</th>
42 * </tr>
43 * <tr>
44 *   <td>hard</td>
45 *   <td> Ability to add an existing file to a directory. This is sometimes
46 *   known as creating a link, or hard link. </td>
47 *   <td> Extreme care should be taken when granting this permission. It allows
48 *   linking to any file or directory in the file system thus allowing the
49 *   attacker access to all files. </td>
50 * </tr>
51 * <tr>
52 *   <td>symbolic</td>
53 *   <td> Ability to create symbolic links. </td>
54 *   <td> Extreme care should be taken when granting this permission. It allows
55 *   linking to any file or directory in the file system thus allowing the
56 *   attacker to access to all files. </td>
57 * </tr>
58 * </table>
59 *
60 * @since 1.7
61 *
62 * @see Files#createLink
63 * @see Files#createSymbolicLink
64 */
65public final class LinkPermission extends BasicPermission {
66    static final long serialVersionUID = -1441492453772213220L;
67
68    private void checkName(String name) {
69        if (!name.equals("hard") && !name.equals("symbolic")) {
70            throw new IllegalArgumentException("name: " + name);
71        }
72    }
73
74    /**
75     * Constructs a {@code LinkPermission} with the specified name.
76     *
77     * @param   name
78     *          the name of the permission. It must be "hard" or "symbolic".
79     *
80     * @throws  IllegalArgumentException
81     *          if name is empty or invalid
82     */
83    public LinkPermission(String name) {
84        super(name);
85        checkName(name);
86    }
87
88    /**
89     * Constructs a {@code LinkPermission} with the specified name.
90     *
91     * @param   name
92     *          the name of the permission; must be "hard" or "symbolic".
93     * @param   actions
94     *          the actions for the permission; must be the empty string or
95     *          {@code null}
96     *
97     * @throws  IllegalArgumentException
98     *          if name is empty or invalid, or actions is a non-empty string
99     */
100    public LinkPermission(String name, String actions) {
101        super(name);
102        checkName(name);
103        if (actions != null && actions.length() > 0) {
104            throw new IllegalArgumentException("actions: " + actions);
105        }
106    }
107}
108