Aaru/Aaru.Devices/Device/ScsiCommands/SMC.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : SMC.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : SCSI Media-changer Commands.
//
// --[ Description ] ----------------------------------------------------------
//
//     Contains SCSI commands defined in SMC standards.
//
// --[ 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
// ****************************************************************************/

namespace Aaru.Devices;

using Aaru.Console;

public partial class Device
{
    /// <summary>Reads an attribute from the medium auxiliary memory, or reports which elements in the changer contain one</summary>
    /// <param name="buffer">Buffer.</param>
    /// <param name="senseBuffer">Sense buffer.</param>
    /// <param name="action">What to do, <see cref="ScsiAttributeAction" />.</param>
    /// <param name="element">Element address.</param>
    /// <param name="elementType">Element type.</param>
    /// <param name="volume">Volume number.</param>
    /// <param name="partition">Partition number.</param>
    /// <param name="firstAttribute">First attribute identificator.</param>
    /// <param name="cache">If set to <c>true</c> device can return cached data.</param>
    /// <param name="timeout">Timeout.</param>
    /// <param name="duration">Duration.</param>
    public bool ReadAttribute(out byte[] buffer, out byte[] senseBuffer, ScsiAttributeAction action, ushort element,
                              byte elementType, byte volume, byte partition, ushort firstAttribute, bool cache,
                              uint timeout, out double duration)
    {
        buffer = new byte[256];
        var cdb = new byte[16];
        senseBuffer = new byte[64];

        cdb[0]  = (byte)ScsiCommands.ReadAttribute;
        cdb[1]  = (byte)((byte)action & 0x1F);
        cdb[2]  = (byte)((element & 0xFF00) >> 8);
        cdb[3]  = (byte)(element     & 0xFF);
        cdb[4]  = (byte)(elementType & 0x0F);
        cdb[5]  = volume;
        cdb[7]  = partition;
        cdb[8]  = (byte)((firstAttribute & 0xFF00) >> 8);
        cdb[9]  = (byte)(firstAttribute & 0xFF);
        cdb[10] = (byte)((buffer.Length & 0xFF000000) >> 24);
        cdb[11] = (byte)((buffer.Length & 0xFF0000)   >> 16);
        cdb[12] = (byte)((buffer.Length & 0xFF00)     >> 8);
        cdb[13] = (byte)(buffer.Length & 0xFF);

        if(cache)
            cdb[14] += 0x01;

        LastError = SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                    out bool sense);

        Error = LastError != 0;

        if(sense)
            return true;

        var attrLen = (uint)((buffer[0] << 24) + (buffer[1] << 16) + (buffer[2] << 8) + buffer[3] + 4);
        buffer      = new byte[attrLen];
        cdb[10]     = (byte)((buffer.Length & 0xFF000000) >> 24);
        cdb[11]     = (byte)((buffer.Length & 0xFF0000)   >> 16);
        cdb[12]     = (byte)((buffer.Length & 0xFF00)     >> 8);
        cdb[13]     = (byte)(buffer.Length & 0xFF);
        senseBuffer = new byte[64];

        LastError = SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                    out sense);

        Error = LastError != 0;

        AaruConsole.DebugWriteLine("SCSI Device", "READ ATTRIBUTE took {0} ms.", duration);

        return sense;
    }
}