Aaru/SCSI/Modes/07.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : 07.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes SCSI MODE PAGE 07h: Verify error recovery 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 © 2011-2022 Natalia Portillo
// ****************************************************************************/

using System.Diagnostics.CodeAnalysis;
using System.Text;

namespace Aaru.Decoders.SCSI
{
    [SuppressMessage("ReSharper", "InconsistentNaming"), SuppressMessage("ReSharper", "MemberCanBeInternal"),
     SuppressMessage("ReSharper", "MemberCanBePrivate.Global"), SuppressMessage("ReSharper", "NotAccessedField.Global")]
    public static partial class Modes
    {
        #region Mode Page 0x07: Verify error recovery page
        /// <summary>Disconnect-reconnect page Page code 0x07 12 bytes in SCSI-2, SBC-1, SBC-2</summary>
        public struct ModePage_07
        {
            /// <summary>Parameters can be saved</summary>
            public bool PS;
            /// <summary>Enable early recovery</summary>
            public bool EER;
            /// <summary>Post error reporting</summary>
            public bool PER;
            /// <summary>Disable transfer on error</summary>
            public bool DTE;
            /// <summary>Disable correction</summary>
            public bool DCR;
            /// <summary>How many times to retry a verify operation</summary>
            public byte VerifyRetryCount;
            /// <summary>How many bits of largest data burst error is maximum to apply error correction on it</summary>
            public byte CorrectionSpan;
            /// <summary>Maximum time in ms to use in data error recovery procedures</summary>
            public ushort RecoveryTimeLimit;
        }

        public static ModePage_07? DecodeModePage_07(byte[] pageResponse)
        {
            if((pageResponse?[0] & 0x40) == 0x40)
                return null;

            if((pageResponse?[0] & 0x3F) != 0x07)
                return null;

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

            if(pageResponse.Length < 12)
                return null;

            var decoded = new ModePage_07();

            decoded.PS  |= (pageResponse[0] & 0x80) == 0x80;
            decoded.EER |= (pageResponse[2] & 0x08) == 0x08;
            decoded.PER |= (pageResponse[2] & 0x04) == 0x04;
            decoded.DTE |= (pageResponse[2] & 0x02) == 0x02;
            decoded.DCR |= (pageResponse[2] & 0x01) == 0x01;

            decoded.VerifyRetryCount  = pageResponse[3];
            decoded.CorrectionSpan    = pageResponse[4];
            decoded.RecoveryTimeLimit = (ushort)((pageResponse[10] << 8) + pageResponse[11]);

            return decoded;
        }

        public static string PrettifyModePage_07(byte[] pageResponse) =>
            PrettifyModePage_07(DecodeModePage_07(pageResponse));

        public static string PrettifyModePage_07(ModePage_07? modePage)
        {
            if(!modePage.HasValue)
                return null;

            ModePage_07 page = modePage.Value;
            var         sb   = new StringBuilder();

            sb.AppendLine("SCSI Verify error recovery page:");

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

            if(page.EER)
                sb.AppendLine("\tDrive will use the most expedient form of error recovery first");

            if(page.PER)
                sb.AppendLine("\tDrive shall report recovered errors");

            if(page.DTE)
                sb.AppendLine("\tTransfer will be terminated upon error detection");

            if(page.DCR)
                sb.AppendLine("\tError correction is disabled");

            if(page.VerifyRetryCount > 0)
                sb.AppendFormat("\tDrive will repeat verify operations {0} times", page.VerifyRetryCount).AppendLine();

            if(page.RecoveryTimeLimit > 0)
                sb.AppendFormat("\tDrive will employ a maximum of {0} ms to recover data", page.RecoveryTimeLimit).
                   AppendLine();

            return sb.ToString();
        }
        #endregion Mode Page 0x07: Verify error recovery page
    }
}