1 // ========================================================================
2 // Copyright (c) 2004-2009 Mort Bay Consulting Pty. Ltd.
3 // ------------------------------------------------------------------------
4 // All rights reserved. This program and the accompanying materials
5 // are made available under the terms of the Eclipse Public License v1.0
6 // and Apache License v2.0 which accompanies this distribution.
7 // The Eclipse Public License is available at
8 // http://www.eclipse.org/legal/epl-v10.html
9 // The Apache License v2.0 is available at
10 // http://www.opensource.org/licenses/apache2.0.php
11 // You may elect to redistribute this code under either of these licenses.
12 // ========================================================================
13
14 package org.eclipse.jetty.server.session;
15
16 import java.security.SecureRandom;
17 import java.util.Random;
18
19 import javax.servlet.http.HttpServletRequest;
20
21 import org.eclipse.jetty.server.SessionIdManager;
22 import org.eclipse.jetty.util.component.AbstractLifeCycle;
23 import org.eclipse.jetty.util.log.Log;
24
25 public abstract class AbstractSessionIdManager extends AbstractLifeCycle implements SessionIdManager
26 {
27 private final static String __NEW_SESSION_ID="org.eclipse.jetty.server.newSessionId";
28
29 protected Random _random;
30 protected boolean _weakRandom;
31 protected String _workerName;
32
33 /* ------------------------------------------------------------ */
34 public AbstractSessionIdManager()
35 {
36 }
37
38 /* ------------------------------------------------------------ */
39 public AbstractSessionIdManager(Random random)
40 {
41 _random=random;
42 }
43
44
45 /* ------------------------------------------------------------ */
46 /**
47 * Get the workname. If set, the workername is dot appended to the session
48 * ID and can be used to assist session affinity in a load balancer.
49 *
50 * @return String or null
51 */
52 public String getWorkerName()
53 {
54 return _workerName;
55 }
56
57 /* ------------------------------------------------------------ */
58 /**
59 * Set the workname. If set, the workername is dot appended to the session
60 * ID and can be used to assist session affinity in a load balancer.
61 *
62 * @param workerName
63 */
64 public void setWorkerName(String workerName)
65 {
66 _workerName=workerName;
67 }
68
69 /* ------------------------------------------------------------ */
70 public Random getRandom()
71 {
72 return _random;
73 }
74
75 /* ------------------------------------------------------------ */
76 public void setRandom(Random random)
77 {
78 _random=random;
79 _weakRandom=false;
80 }
81
82 /* ------------------------------------------------------------ */
83 /**
84 * Create a new session id if necessary.
85 *
86 * @see org.eclipse.jetty.server.SessionIdManager#newSessionId(javax.servlet.http.HttpServletRequest, long)
87 */
88 public String newSessionId(HttpServletRequest request, long created)
89 {
90 synchronized (this)
91 {
92 if (request!=null)
93 {
94 // A requested session ID can only be used if it is in use already.
95 String requested_id=request.getRequestedSessionId();
96 if (requested_id!=null)
97 {
98 String cluster_id=getClusterId(requested_id);
99 if (idInUse(cluster_id))
100 return cluster_id;
101 }
102
103 // Else reuse any new session ID already defined for this request.
104 String new_id=(String)request.getAttribute(__NEW_SESSION_ID);
105 if (new_id!=null&&idInUse(new_id))
106 return new_id;
107 }
108
109 // pick a new unique ID!
110 String id=null;
111 while (id==null||id.length()==0||idInUse(id))
112 {
113 long r0=_weakRandom
114 ?(hashCode()^Runtime.getRuntime().freeMemory()^_random.nextInt()^(((long)request.hashCode())<<32))
115 :_random.nextLong();
116 if (r0<0)
117 r0=-r0;
118 long r1=_weakRandom
119 ?(hashCode()^Runtime.getRuntime().freeMemory()^_random.nextInt()^(((long)request.hashCode())<<32))
120 :_random.nextLong();
121 if (r1<0)
122 r1=-r1;
123 id=Long.toString(r0,36)+Long.toString(r1,36);
124
125 //add in the id of the node to ensure unique id across cluster
126 //NOTE this is different to the node suffix which denotes which node the request was received on
127 if (_workerName!=null)
128 id=_workerName + id;
129 }
130
131 request.setAttribute(__NEW_SESSION_ID,id);
132 return id;
133 }
134 }
135
136 /* ------------------------------------------------------------ */
137 @Override
138 protected void doStart() throws Exception
139 {
140 initRandom();
141 }
142
143 /* ------------------------------------------------------------ */
144 @Override
145 protected void doStop() throws Exception
146 {
147 }
148
149 /* ------------------------------------------------------------ */
150 /**
151 * Set up a random number generator for the sessionids.
152 *
153 * By preference, use a SecureRandom but allow to be injected.
154 */
155 public void initRandom ()
156 {
157 if (_random==null)
158 {
159 try
160 {
161 _random=new SecureRandom();
162 }
163 catch (Exception e)
164 {
165 Log.warn("Could not generate SecureRandom for session-id randomness",e);
166 _random=new Random();
167 _weakRandom=true;
168 }
169 }
170 _random.setSeed(_random.nextLong()^System.currentTimeMillis()^hashCode()^Runtime.getRuntime().freeMemory());
171 }
172
173
174 }