1 package org.jscsi.target.scsi.cdb;
2
3 /**
4 * The {@link CdbType} determines the length of a serialized {@link CommandDescriptorBlock} (CDB) object.
5 * <p>
6 * The first 3 bytes (the group code) of the CDB's {@link ScsiOperationCode} field specify the {@link CdbType}.
7 *
8 * @author Andreas Ergenzinger
9 */
10 public enum CdbType {
11 /**
12 * The CDB is 6 bytes long.
13 */
14 SIX_BYTE_COMMANDS,
15 /**
16 * The CDB is 10 bytes long.
17 */
18 TEN_BYTE_COMMANDS,
19 /**
20 * The CDB is 12 bytes long.
21 */
22 TWELVE_BYTE_COMMANDS,
23 /**
24 * The CDB is 16 bytes long.
25 */
26 SIXTEEN_BYTE_COMMANDS,
27 /**
28 * The CDB length is not determined by the CDB's {@link ScsiOperationCode} field.
29 */
30 VARIABLE_LENGTH_COMMANDS,
31 /**
32 * The CDB length is vendor-specific.
33 */
34 VENDOR_SPECIFIC;
35
36 /**
37 * Returns the {@link CdbType} for the passed {@link ScsiOperationCode}.
38 *
39 * @param scsiOpCode determines CDB length
40 * @return the appropriate {@link CdbType}
41 */
42 public static CdbType getCdbType (ScsiOperationCode scsiOpCode) {
43 final int groupCode = scsiOpCode.getGroupCode();
44
45 switch (groupCode) {
46 case 0 :// 000b
47 return SIX_BYTE_COMMANDS;
48 case 1 :// 001b
49 case 2 :// 010b
50 return TEN_BYTE_COMMANDS;
51 case 3 :// 011b
52 return VARIABLE_LENGTH_COMMANDS;
53 case 4 :// 100b
54 return SIXTEEN_BYTE_COMMANDS;
55 case 5 :// 101b
56 return TWELVE_BYTE_COMMANDS;
57 case 6 :// 110b
58 case 7 :// 111b
59 return VENDOR_SPECIFIC;
60 default :
61 return null;// this really should not happen!
62 }
63 }
64
65 }