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1   /**
2    * Copyright (c) 2012, University of Konstanz, Distributed Systems Group All rights reserved.
3    * 
4    * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
5    * following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of
6    * conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice,
7    * this list of conditions and the following disclaimer in the documentation and/or other materials provided with the
8    * distribution. * Neither the name of the University of Konstanz nor the names of its contributors may be used to
9    * endorse or promote products derived from this software without specific prior written permission.
10   * 
11   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
12   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
13   * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
14   * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
15   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
16   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
17   * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
18   */
19  package org.jscsi.initiator.connection.state;
20  
21  
22  import org.jscsi.exception.InternetSCSIException;
23  import org.jscsi.initiator.connection.Connection;
24  import org.jscsi.parser.OperationCode;
25  import org.jscsi.parser.ProtocolDataUnit;
26  import org.jscsi.parser.datasegment.OperationalTextKey;
27  import org.jscsi.parser.snack.SNACKRequestParser;
28  import org.jscsi.parser.snack.SNACKRequestParser.SNACKType;
29  
30  
31  /**
32   * <h1>SNACKRequestState</h1>
33   * <p/>
34   * This state handles a SNACK Request.
35   * 
36   * @author Volker Wildi
37   */
38  public final class SNACKRequestState extends AbstractState {
39  
40      // --------------------------------------------------------------------------
41      // --------------------------------------------------------------------------
42  
43      private final IState prevState;
44  
45      private final int targetTransferTag;
46  
47      // --------------------------------------------------------------------------
48      // --------------------------------------------------------------------------
49  
50      /**
51       * Constructor to create a new, empty <code>SNACKRequestState</code>.
52       * 
53       * @param initConnection This is the connection, which is used for the network transmission.
54       * @param initPrevState The <code>IState</code> instance, which was executed before this state.
55       * @param initTargetTransferTag The Target Transfer Tag of this state.
56       */
57      public SNACKRequestState (final Connection initConnection, final IState initPrevState, final int initTargetTransferTag) {
58  
59          super(initConnection);
60          prevState = initPrevState;
61          targetTransferTag = initTargetTransferTag;
62      }
63  
64      // --------------------------------------------------------------------------
65      // --------------------------------------------------------------------------
66  
67      /** {@inheritDoc} */
68      public final void execute () throws InternetSCSIException {
69  
70          final ProtocolDataUnit protocolDataUnit = protocolDataUnitFactory.create(false, true, OperationCode.SNACK_REQUEST, connection.getSetting(OperationalTextKey.HEADER_DIGEST), connection.getSetting(OperationalTextKey.DATA_DIGEST));
71  
72          final SNACKRequestParser parser = (SNACKRequestParser) protocolDataUnit.getBasicHeaderSegment().getParser();
73          parser.setType(SNACKType.DATA_ACK);
74          parser.setTargetTransferTag(targetTransferTag);
75  
76          connection.send(protocolDataUnit);
77          connection.nextState(prevState);
78          super.stateFollowing = true;
79          // return true;
80      }
81  
82      // --------------------------------------------------------------------------
83      // --------------------------------------------------------------------------
84      // --------------------------------------------------------------------------
85      // --------------------------------------------------------------------------
86  
87  }