DaemonPermission


1   /*
2    *  Copyright 2001-2004 The Apache Software Foundation
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License");
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License.
15   */
16  
17  package org.apache.commons.daemon;
18  
19  import java.security.Permission  ;
20  import java.util.StringTokenizer  ;
21  
22  /**
23   * This class represents the permissions to control and query the status of
24   * a <code>Daemon</code>. A <code>DaemonPermission</code> consists of a
25   * target name and a list of actions associated with it.
26   * <p>
27   * In this specification version the only available target name for this
28   * permission is &quot;control&quot;, but further releases may add more target
29   * names to fine-tune the access that needs to be granted to the caller.
30   * </p>
31   * <p>
32   * Actions are defined by a string of comma-separated values, as shown in the
33   * table below. The empty string implies no permission at all, while the
34   * special &quot;*&quot; value implies all permissions for the given
35   * name:
36   * </p>
37   * <p>
38   * <table width="100%" border="1">
39   *  <tr>
40   *   <th>Target&quot;Name</th>
41   *   <th>Action</th>
42   *   <th>Description</th>
43   *  </tr>
44   *  <tr>
45   *   <td rowspan="5">&quot;control&quot;</td>
46   *   <td>&quot;start&quot;</td>
47   *   <td>
48   *    The permission to call the <code>start()</code> method in an instance
49   *    of a <code>DaemonController</code> interface.
50   *   </td>
51   *  </tr>
52   *  <tr>
53   *   <td>&quot;stop&quot;</td>
54   *   <td>
55   *    The permission to call the <code>stop()</code> method in an instance
56   *    of a <code>DaemonController</code> interface.
57   *   </td>
58   *  </tr>
59   *  <tr>
60   *   <td>&quot;shutdown&quot;</td>
61   *   <td>
62   *    The permission to call the <code>shutdown()</code> method in an instance
63   *    of a <code>DaemonController</code> interface.
64   *   </td>
65   *  </tr>
66   *  <tr>
67   *   <td>&quot;reload&quot;</td>
68   *   <td>
69   *    The permission to call the <code>reload()</code> method in an instance
70   *    of a <code>DaemonController</code> interface.
71   *   </td>
72   *  </tr>
73   *  <tr>
74   *   <td>&quot;*&quot;</td>
75   *   <td>
76   *    The special wildcard action implies all above-mentioned action. This is
77   *    equal to construct a permission with the &quot;start, stop, shutdown,
78   *    reload&quot; list of actions.
79   *   </td>
80   *  </tr>
81   * </table>
82   * </p>
83   *
84   * @author Pier Fumagalli
85   * @author Copyright &copy; 2000-2001 <a HREF="http://www.apache.org/">The
86   *         Apache Software Foundation</a>. All rights reserved.
87   * @version 1.0 <i>(CVS $Revision: 155409 $)</i>
88   */
89  public final class DaemonPermission extends Permission   {
90  
91      /* ==================================================================== */
92      /* Constants. */
93  
94      /**
95       * The target name when associated with control actions
96       * (&quot;control&quot;).
97       */
98      protected static final String   CONTROL = "control";
99  
100     /**
101      * The target type when associated with control actions.
102      */
103     protected static final int TYPE_CONTROL = 1;
104 
105     /**
106      * The action name associated with the permission to call the
107      * <code>DaemonController.start()</code> method.
108      */
109     protected static final String   CONTROL_START = "start";
110 
111     /**
112      * The action name associated with the permission to call the
113      * <code>DaemonController.stop()</code> method.
114      */
115     protected static final String   CONTROL_STOP = "stop";
116 
117     /**
118      * The action name associated with the permission to call the
119      * <code>DaemonController.shutdown()</code> method.
120      */
121     protected static final String   CONTROL_SHUTDOWN = "shutdown";
122 
123     /**
124      * The action name associated with the permission to call the
125      * <code>DaemonController.reload()</code> method.
126      */
127     protected static final String   CONTROL_RELOAD = "reload";
128 
129     /**
130      * The action mask associated with the permission to call the
131      * <code>DaemonController.start()</code> method.
132      */
133     protected static final int MASK_CONTROL_START = 0x01;
134 
135     /**
136      * The action mask associated with the permission to call the
137      * <code>DaemonController.stop()</code> method.
138      */
139     protected static final int MASK_CONTROL_STOP = 0x02;
140 
141     /**
142      * The action mask associated with the permission to call the
143      * <code>DaemonController.shutdown()</code> method.
144      */
145     protected static final int MASK_CONTROL_SHUTDOWN = 0x04;
146 
147     /**
148      * The action mask associated with the permission to call the
149      * <code>DaemonController.reload()</code> method.
150      */
151     protected static final int MASK_CONTROL_RELOAD = 0x08;
152 
153     /**
154      * The &quot;wildcard&quot; action implying all actions for the given
155      * target name.
156      */
157     protected static final String   WILDCARD = "*";
158 
159     /* ==================================================================== */
160     /* Instance variables */
161 
162     /** The type of this permission object. */
163     private transient int type = 0;
164     /** The permission mask associated with this permission object. */
165     private transient int mask = 0;
166     /** The String representation of this permission object. */
167     private transient String   desc = null;
168 
169     /* ==================================================================== */
170     /* Constructors */
171 
172     /**
173      * Create a new <code>DaemonPermission</code> instance with a specified
174      * permission name.
175      * <p>
176      * This constructor will create a new <code>DaemonPermission</code>
177      * instance that <b>will not</b> grant any permission to the caller.
178      *
179      * @param target The target name of this permission.
180      * @exception IllegalArgumentException If the specified target name is not
181      *                supported.
182      */
183     public DaemonPermission (String   target)
184     throws IllegalArgumentException   {
185         // Setup the target name of this permission object.
186         super(target);
187 
188         // Check if the permission target name was specified
189         if (target==null)
190             throw new IllegalArgumentException  ("Null permission name");
191 
192         // Check if this is a "control" permission and set up accordingly.
193         if (CONTROL.equalsIgnoreCase(target)) {
194             type=TYPE_CONTROL;
195             return;
196         }
197 
198         // If we got here, we have an invalid permission name.
199         throw new IllegalArgumentException  ("Invalid permission name \""+
200                                            target+"\" specified");
201     }
202 
203     /**
204      * Create a new <code>DaemonPermission</code> instance with a specified
205      * permission name and a specified list of actions.
206      * <p>
207      * </p>
208      *
209      * @param target The target name of this permission.
210      * @param actions The list of actions permitted by this permission.
211      * @exception IllegalArgumentException If the specified target name is not
212      *                supported, or the specified list of actions includes an
213      *                invalid value.
214      */
215     public DaemonPermission(String   target, String   actions)
216     throws IllegalArgumentException   {
217         // Setup this instance's target name.
218         this(target);
219 
220         // Create the appropriate mask if this is a control permission.
221         if (this.type==TYPE_CONTROL) {
222             this.mask=this.createControlMask(actions);
223             return;
224         }
225     }
226 
227     /* ==================================================================== */
228     /* Public methods */
229 
230     /**
231      * Return the list of actions permitted by this instance of
232      * <code>DaemonPermission</code> in its canonical form.
233      *
234      * @return The canonicalized list of actions.
235      */
236     public String   getActions() {
237         if (this.type==TYPE_CONTROL) {
238             return(this.createControlActions(this.mask));
239         }
240         return("");
241     }
242 
243     /**
244      * Return the hash code for this <code>DaemonPermission</code> instance.
245      *
246      * @return An hash code value.
247      */
248     public int hashCode() {
249         this.setupDescription();
250         return(this.desc.hashCode());
251     }
252 
253     /**
254      * Check if a specified object equals <code>DaemonPermission</code>.
255      *
256      * @return <b>true</b> or <b>false</b> wether the specified object equals
257      *         this <code>DaemonPermission</code> instance or not.
258      */
259     public boolean equals(Object   object) {
260         if (object == this) return(true);
261 
262         if (!(object instanceof DaemonPermission)) return false;
263 
264         DaemonPermission that = (DaemonPermission)object;
265 
266         if (this.type!=that.type) return(false);
267         return(this.mask==that.mask);
268     }
269 
270     /**
271      * Check if this <code>DaemonPermission</code> implies another
272      * <code>Permission</code>.
273      *
274      * @return <b>true</b> or <b>false</b> wether the specified permission
275      *         is implied by this <code>DaemonPermission</code> instance or
276      *         not.
277      */
278     public boolean implies(Permission   permission) {
279         if (permission == this) return(true);
280 
281         if (!(permission instanceof DaemonPermission)) return false;
282 
283         DaemonPermission that = (DaemonPermission)permission;
284 
285         if (this.type!=that.type) return(false);
286         return((this.mask&that.mask)==that.mask);
287     }
288 
289     /**
290      * Return a <code>String</code> representation of this instance.
291      *
292      * @return A <code>String</code> representing this
293      *         <code>DaemonPermission</code> instance.
294      */
295     public String   toString() {
296         this.setupDescription();
297         return(new String  (this.desc));
298     }
299 
300     /* ==================================================================== */
301     /* Private methods */
302 
303     /** Create a String description for this permission instance. */
304     private void setupDescription() {
305         if (this.desc!=null) return;
306 
307         StringBuffer   buf=new StringBuffer  ();
308         buf.append(this.getClass().getName());
309         buf.append('[');
310         switch (this.type) {
311             case (TYPE_CONTROL): {
312                 buf.append(CONTROL);
313                 break;
314             }
315             default: {
316                 buf.append("UNKNOWN");
317                 break;
318             }
319         }
320         buf.append(':');
321         buf.append(this.getActions());
322         buf.append(']');
323 
324         this.desc=buf.toString();
325     }
326 
327     /** Create a permission mask for a given control actions string. */
328     private int createControlMask(String   actions)
329     throws IllegalArgumentException   {
330         if (actions==null) return(0);
331 
332         int mask=0;
333         StringTokenizer   tok=new StringTokenizer  (actions,",",false);
334         while (tok.hasMoreTokens()) {
335             String   val=tok.nextToken().trim();
336 
337             if (WILDCARD.equals(val)) {
338                 return(MASK_CONTROL_START|MASK_CONTROL_STOP|
339                        MASK_CONTROL_SHUTDOWN|MASK_CONTROL_RELOAD);
340             } else if (CONTROL_START.equalsIgnoreCase(val)) {
341                 mask=mask|MASK_CONTROL_START;
342             } else if (CONTROL_STOP.equalsIgnoreCase(val)) {
343                 mask=mask|MASK_CONTROL_STOP;
344             } else if (CONTROL_SHUTDOWN.equalsIgnoreCase(val)) {
345                 mask=mask|MASK_CONTROL_SHUTDOWN;
346             } else if (CONTROL_RELOAD.equalsIgnoreCase(val)) {
347                 mask=mask|MASK_CONTROL_RELOAD;
348             } else {
349                 throw new IllegalArgumentException  ("Invalid action name \""+
350                                                    val+"\" specified");
351             }
352         }
353         return(mask);
354     }
355 
356     /** Create a actions list for a given control permission mask. */
357     private String   createControlActions(int mask) {
358         StringBuffer   buf=new StringBuffer  ();
359         boolean sep=false;
360 
361         if ((mask&MASK_CONTROL_START)==MASK_CONTROL_START) {
362             sep=true;
363             buf.append(CONTROL_START);
364         }
365 
366         if ((mask&MASK_CONTROL_STOP)==MASK_CONTROL_STOP) {
367             if (sep) buf.append(",");
368             else sep=true;
369             buf.append(CONTROL_STOP);
370         }
371 
372         if ((mask&MASK_CONTROL_SHUTDOWN)==MASK_CONTROL_SHUTDOWN) {
373             if (sep) buf.append(",");
374             else sep=true;
375             buf.append(CONTROL_SHUTDOWN);
376         }
377 
378         if ((mask&MASK_CONTROL_RELOAD)==MASK_CONTROL_RELOAD) {
379             if (sep) buf.append(",");
380             else sep=true;
381             buf.append(CONTROL_RELOAD);
382         }
383 
384         return buf.toString();
385     }
386 }
387
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