Aaru/SCSI/Modes/1D.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : 1D.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes SCSI MODE PAGE 1Dh: Medium Configuration Mode Page.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library is distributed in the hope that it will be useful, but
//     WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2018 Natalia Portillo
// ****************************************************************************/

using System.Text;

namespace DiscImageChef.Decoders.SCSI
{
    public static partial class Modes
    {
        #region Mode Page 0x1D: Medium Configuration Mode Page
        public struct ModePage_1D
        {
            /// <summary>
            /// Parameters can be saved
            /// </summary>
            public bool PS;
            public bool WORMM;
            public byte WormModeLabelRestrictions;
            public byte WormModeFilemarkRestrictions;
        }

        public static ModePage_1D? DecodeModePage_1D(byte[] pageResponse)
        {
            if((pageResponse?[0] & 0x40) == 0x40) return null;

            if((pageResponse?[0] & 0x3F) != 0x1D) return null;

            if(pageResponse[1] + 2 != pageResponse.Length) return null;

            if(pageResponse.Length < 32) return null;

            ModePage_1D decoded = new ModePage_1D();

            decoded.PS |= (pageResponse[0] & 0x80) == 0x80;
            decoded.WORMM |= (pageResponse[2] & 0x01) == 0x01;
            decoded.WormModeLabelRestrictions = pageResponse[4];
            decoded.WormModeFilemarkRestrictions = pageResponse[5];

            return decoded;
        }

        public static string PrettifyModePage_1D(byte[] pageResponse)
        {
            return PrettifyModePage_1D(DecodeModePage_1D(pageResponse));
        }

        public static string PrettifyModePage_1D(ModePage_1D? modePage)
        {
            if(!modePage.HasValue) return null;

            ModePage_1D page = modePage.Value;
            StringBuilder sb = new StringBuilder();

            sb.AppendLine("SCSI Medium Configuration Mode Page:");

            if(page.PS) sb.AppendLine("\tParameters can be saved");

            if(page.WORMM) sb.AppendLine("\tDrive is operating in WORM mode");

            switch(page.WormModeLabelRestrictions)
            {
                case 0:
                    sb.AppendLine("\tDrive does not allow any logical blocks to be overwritten");
                    break;
                case 1:
                    sb.AppendLine("\tDrive allows a tape header to be overwritten");
                    break;
                case 2:
                    sb.AppendLine("\tDrive allows all format labels to be overwritten");
                    break;
                default:
                    sb.AppendFormat("\tUnknown WORM mode label restrictions code {0}", page.WormModeLabelRestrictions)
                      .AppendLine();
                    break;
            }

            switch(page.WormModeFilemarkRestrictions)
            {
                case 2:
                    sb.AppendLine("\tDrive allows any number of filemarks immediately preceding EOD to be overwritten except filemark closes to BOP");
                    break;
                case 3:
                    sb.AppendLine("\tDrive allows any number of filemarks immediately preceding EOD to be overwritten");
                    break;
                default:
                    sb.AppendFormat("\tUnknown WORM mode filemark restrictions code {0}",
                                    page.WormModeLabelRestrictions).AppendLine();
                    break;
            }

            return sb.ToString();
        }
        #endregion Mode Page 0x1D: Medium Configuration Mode Page
    }
}