1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.server.dhcp.store;
21
22
23 import java.net.InetAddress;
24 import java.util.Map;
25
26 import org.apache.directory.server.dhcp.DhcpException;
27 import org.apache.directory.server.dhcp.messages.HardwareAddress;
28 import org.apache.directory.server.dhcp.options.OptionsField;
29 import org.apache.directory.server.dhcp.options.vendor.HostName;
30 import org.apache.directory.server.dhcp.options.vendor.SubnetMask;
31 import org.apache.directory.server.dhcp.service.Lease;
32 import org.slf4j.Logger;
33 import org.slf4j.LoggerFactory;
34
35
36 /**
37 * Abstract base implementation of a {@link DhcpStore}.
38 *
39 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
40 */
41 public abstract class AbstractDhcpStore implements DhcpStore
42 {
43 private static final Logger LOG = LoggerFactory.getLogger( AbstractDhcpStore.class );
44
45
46 /*
47 * @see org.apache.directory.server.dhcp.service.DhcpStore#getLeaseOffer(org.apache.directory.server.dhcp.messages.HardwareAddress,
48 * java.net.InetAddress, java.net.InetAddress, long,
49 * org.apache.directory.server.dhcp.options.OptionsField)
50 */
51 public Lease getLeaseOffer( HardwareAddress hardwareAddress, InetAddress requestedAddress,
52 InetAddress selectionBase, long requestedLeaseTime, OptionsField options ) throws DhcpException
53 {
54 Subnet subnet = findSubnet( selectionBase );
55
56 if ( null == subnet )
57 {
58 LOG.warn( "Don't know anything about the sbnet containing {}", selectionBase );
59 return null;
60 }
61
62 // try to find existing lease
63 Lease lease = null;
64 lease = findExistingLease( hardwareAddress, lease );
65
66 if ( null != lease )
67 {
68 return lease;
69 }
70
71 Host host = null;
72 host = findDesignatedHost( hardwareAddress );
73
74 if ( null != host )
75 {
76 // make sure that the host is actually within the subnet. Depending
77 // on the way the DhcpStore configuration is implemented, it is not
78 // possible to violate this condition, but we can't be sure.
79 if ( !subnet.contains( host.getAddress() ) )
80 {
81 LOG.warn( "Host {} is not within the subnet for which an address is requested", host );
82 }
83 else
84 {
85 // build properties map
86 Map properties = getProperties( subnet );
87 properties.putAll( getProperties( host ) );
88
89 // build lease
90 lease = new Lease();
91 lease.setAcquired( System.currentTimeMillis() );
92
93 long leaseTime = determineLeaseTime( requestedLeaseTime, properties );
94
95 lease.setExpires( System.currentTimeMillis() + leaseTime );
96
97 lease.setHardwareAddress( hardwareAddress );
98 lease.setState( Lease.STATE_NEW );
99 lease.setClientAddress( host.getAddress() );
100
101 // set lease options
102 OptionsField o = lease.getOptions();
103
104 // set (client) host name
105 o.add( new HostName( host.getName() ) );
106
107 // add subnet settings
108 o.add( new SubnetMask( subnet.getNetmask() ) );
109 o.merge( subnet.getOptions() );
110
111 // add the host's options. they override existing
112 // subnet options as they take the precedence.
113 o.merge( host.getOptions() );
114 }
115 }
116
117 // update the lease state
118 if ( null != lease && lease.getState() != Lease.STATE_ACTIVE )
119 {
120 lease.setState( Lease.STATE_OFFERED );
121 updateLease( lease );
122 }
123
124 return lease;
125 }
126
127
128 /*
129 * @see org.apache.directory.server.dhcp.store.DhcpStore#getExistingLease(org.apache.directory.server.dhcp.messages.HardwareAddress,
130 * java.net.InetAddress, java.net.InetAddress, long,
131 * org.apache.directory.server.dhcp.options.OptionsField)
132 */
133 public Lease getExistingLease( HardwareAddress hardwareAddress, InetAddress requestedAddress,
134 InetAddress selectionBase, long requestedLeaseTime, OptionsField options ) throws DhcpException
135 {
136 // try to find existing lease. if we don't find a lease based on the
137 // client's
138 // hardware address, we send a NAK.
139 Lease lease = null;
140 lease = findExistingLease( hardwareAddress, lease );
141
142 if ( null == lease )
143 {
144 return null;
145 }
146
147 // check whether the notions of the client address match
148 if ( !lease.getClientAddress().equals( requestedAddress ) )
149 {
150 LOG.warn( "Requested address " + requestedAddress + " for " + hardwareAddress
151 + " doesn't match existing lease " + lease );
152 return null;
153 }
154
155 // check whether addresses and subnet match
156 Subnet subnet = findSubnet( selectionBase );
157
158 if ( null == subnet )
159 {
160 LOG.warn( "No subnet found for existing lease {}", lease );
161 return null;
162 }
163
164 if ( !subnet.contains( lease.getClientAddress() ) )
165 {
166 LOG.warn( "Client with existing lease {} is on wrong subnet {}", lease, subnet );
167 return null;
168 }
169
170 if ( !subnet.isInRange( lease.getClientAddress() ) )
171 {
172 LOG.warn( "Client with existing lease {} is out of valid range for subnet {}", lease, subnet );
173 return null;
174 }
175
176 // build properties map
177 Map properties = getProperties( subnet );
178
179 // update lease options
180 OptionsField o = lease.getOptions();
181 o.clear();
182
183 // add subnet settings
184 o.add( new SubnetMask( subnet.getNetmask() ) );
185 o.merge( subnet.getOptions() );
186
187 // check whether there is a designated host.
188 Host host = findDesignatedHost( hardwareAddress );
189 if ( null != host )
190 {
191 // check whether the host matches the address (using a fixed
192 // host address is mandatory).
193 if ( host.getAddress() != null && !host.getAddress().equals( lease.getClientAddress() ) )
194 {
195 LOG.warn( "Existing fixed address for " + hardwareAddress + " conflicts with existing lease "
196 + lease );
197 return null;
198 }
199
200 properties.putAll( getProperties( host ) );
201
202 // set (client) host name
203 o.add( new HostName( host.getName() ) );
204
205 // add the host's options
206 o.merge( host.getOptions() );
207 }
208
209 // update other lease fields
210 long leaseTime = determineLeaseTime( requestedLeaseTime, properties );
211 lease.setExpires( System.currentTimeMillis() + leaseTime );
212 lease.setHardwareAddress( hardwareAddress );
213
214 // update the lease state
215 if ( lease.getState() != Lease.STATE_ACTIVE )
216 {
217 lease.setState( Lease.STATE_ACTIVE );
218 updateLease( lease );
219 }
220
221 // store information about the lease
222 updateLease( lease );
223
224 return lease;
225 }
226
227
228 /**
229 * Determine the lease time based on the time requested by the client, the
230 * properties and a global default.
231 *
232 * @param requestedLeaseTime
233 * @param properties
234 * @return long
235 */
236 private long determineLeaseTime( long requestedLeaseTime, Map properties )
237 {
238 // built-in default
239 long leaseTime = 1000L * 3600;
240 Integer propMaxLeaseTime = ( Integer ) properties.get( DhcpConfigElement.PROPERTY_MAX_LEASE_TIME );
241
242 if ( null != propMaxLeaseTime )
243 {
244 if ( requestedLeaseTime > 0 )
245 {
246 leaseTime = Math.min( propMaxLeaseTime.intValue() * 1000L, requestedLeaseTime );
247 }
248 else
249 {
250 leaseTime = propMaxLeaseTime.intValue() * 1000L;
251 }
252 }
253
254 return leaseTime;
255 }
256
257
258 /*
259 * @see org.apache.directory.server.dhcp.store.DhcpStore#releaseLease(org.apache.directory.server.dhcp.service.Lease)
260 */
261 public void releaseLease( Lease lease )
262 {
263 lease.setState( Lease.STATE_RELEASED );
264 updateLease( lease );
265 }
266
267
268 /**
269 * Update the (possibly changed) lease in the store.
270 *
271 * @param lease
272 */
273 protected abstract void updateLease( Lease lease );
274
275
276 /**
277 * Return a list of all options applicable to the given config element. List
278 * list must contain the options specified for the element and all parent
279 * elements in an aggregated fashion. For instance, the options for a host
280 * must include the global default options, the options of classes the host
281 * is a member of, the host's group options and the host's options.
282 *
283 * @param element
284 * @return OptionsField
285 */
286 protected abstract OptionsField getOptions( DhcpConfigElement element );
287
288
289 /**
290 * Return a list of all options applicable to the given config element. List
291 * list must contain the options specified for the element and all parent
292 * elements in an aggregated fashion. For instance, the options for a host
293 * must include the global default options, the options of classes the host
294 * is a member of, the host's group options and the host's options.
295 *
296 * @param element
297 * @return Map
298 */
299 protected abstract Map getProperties( DhcpConfigElement element );
300
301
302 /**
303 * Find an existing lease in the store.
304 *
305 * @param hardwareAddress
306 * @param existingLease
307 * @return Map
308 */
309 protected abstract Leaserver/dhcp/service/Lease.html#Lease">Lease findExistingLease( HardwareAddress hardwareAddress, Lease existingLease );
310
311
312 /**
313 * Find a host to with the explicitely designated hardware address.
314 *
315 * @param hardwareAddress
316 * @return Host
317 * @throws DhcpException
318 */
319 protected abstract Host findDesignatedHost( HardwareAddress hardwareAddress ) throws DhcpException;
320
321
322 /**
323 * Find the subnet definition matching the given address.
324 *
325 * @param clientAddress
326 * @return Subnet
327 */
328 protected abstract Subnet findSubnet( InetAddress clientAddress );
329 }