Aaru/DVD/Cartridge.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Cartridge.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes DVD cartridge structures.
//
// --[ 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.DVD
{
    /// <summary>
    /// Information from the following standards:
    /// ANSI X3.304-1997
    /// T10/1048-D revision 9.0
    /// T10/1048-D revision 10a
    /// T10/1228-D revision 7.0c
    /// T10/1228-D revision 11a
    /// T10/1363-D revision 10g
    /// T10/1545-D revision 1d
    /// T10/1545-D revision 5
    /// T10/1545-D revision 5a
    /// T10/1675-D revision 2c
    /// T10/1675-D revision 4
    /// T10/1836-D revision 2g
    /// </summary>
    public static class Cartridge
    {
        public struct MediumStatus
        {
            /// <summary>
            /// Bytes 0 to 1
            /// Data length
            /// </summary>
            public ushort DataLength;
            /// <summary>
            /// Byte 2
            /// Reserved
            /// </summary>
            public byte Reserved1;
            /// <summary>
            /// Byte 3
            /// Reserved
            /// </summary>
            public byte Reserved2;
            /// <summary>
            /// Byte 4, bit 7
            /// Medium is in a cartridge
            /// </summary>
            public bool Cartridge;
            /// <summary>
            /// Byte 4, bit 6
            /// Medium has been taken out/inserted in a cartridge
            /// </summary>
            public bool OUT;
            /// <summary>
            /// Byte 4, bits 5 to 4
            /// Reserved
            /// </summary>
            public byte Reserved3;
            /// <summary>
            /// Byte 4, bit 3
            /// Media is write protected by reason stablished in RAMSWI
            /// </summary>
            public bool MSWI;
            /// <summary>
            /// Byte 4, bit 2
            /// Media is write protected by cartridge
            /// </summary>
            public bool CWP;
            /// <summary>
            /// Byte 4, bit 1
            /// Media is persistently write protected
            /// </summary>
            public bool PWP;
            /// <summary>
            /// Byte 4, bit 0
            /// Reserved
            /// </summary>
            public bool Reserved4;
            /// <summary>
            /// Byte 5
            /// Writable status depending on cartridge
            /// </summary>
            public byte DiscType;
            /// <summary>
            /// Byte 6
            /// Reserved
            /// </summary>
            public byte Reserved5;
            /// <summary>
            /// Byte 7
            /// Reason of specific write protection, only defined 0x01 as "bare disc wp", and 0xFF as unspecified. Rest reserved.
            /// </summary>
            public byte RAMSWI;
        }

        public static MediumStatus? Decode(byte[] response)
        {
            if(response == null) return null;

            if(response.Length != 8) return null;

            MediumStatus status = new MediumStatus();

            status.DataLength = (ushort)((response[0] << 8) + response[1]);
            status.Reserved1 = response[2];
            status.Reserved2 = response[3];
            status.Cartridge |= (response[4] & 0x80) == 0x80;
            status.OUT |= (response[4] & 0x40) == 0x40;
            status.Reserved3 = (byte)((response[4] & 0x30) >> 4);
            status.MSWI |= (response[4] & 0x08) == 0x08;
            status.CWP |= (response[4] & 0x04) == 0x04;
            status.PWP |= (response[4] & 0x02) == 0x02;
            status.Reserved4 |= (response[4] & 0x01) == 0x01;
            status.DiscType = response[5];
            status.Reserved5 = response[6];
            status.RAMSWI = response[7];

            return status;
        }

        public static string Prettify(MediumStatus? status)
        {
            if(status == null) return null;

            MediumStatus decoded = status.Value;
            StringBuilder sb = new StringBuilder();

            if(decoded.PWP) sb.AppendLine("Disc surface is set to write protected status");

            if(decoded.Cartridge)
            {
                sb.AppendLine("Disc comes in a cartridge");
                if(decoded.OUT) sb.AppendLine("Disc has been extracted from the cartridge");
                if(decoded.CWP) sb.AppendLine("Cartridge is set to write protected");
            }

            switch(decoded.DiscType)
            {
                case 0:
                    sb.AppendLine("Disc shall not be written without a cartridge");
                    break;
                case 0x10:
                    sb.AppendLine("Disc may be written without a cartridge");
                    break;
                default:
                    sb.AppendFormat("Unknown disc type id {0}", decoded.DiscType).AppendLine();
                    break;
            }

            if(!decoded.MSWI) return sb.ToString();

            switch(decoded.RAMSWI)
            {
                case 0: break;
                case 1:
                    sb.AppendLine("Disc is write inhibited because it has been extracted from the cartridge");
                    break;
                case 0xFF:
                    sb.AppendLine("Disc is write inhibited for an unspecified reason");
                    break;
                default:
                    sb.AppendFormat("Disc has unknown reason {0} for write inhibition", decoded.RAMSWI)
                      .AppendLine();
                    break;
            }

            return sb.ToString();
        }

        public static string Prettify(byte[] response)
        {
            return Prettify(Decode(response));
        }
    }
}