Aaru/Aaru.Filesystems/ISO9660/Xattr.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Xattr.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : ISO9660 filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Handles extended attributes
//
// --[ 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 © 2011-2023 Natalia Portillo
// In the loving memory of Facunda "Tata" Suárez Domínguez, R.I.P. 2019/07/24
// ****************************************************************************/

using System;
using System.Collections.Generic;
using Aaru.CommonTypes.Enums;
using Aaru.Helpers;

namespace Aaru.Filesystems;

public sealed partial class ISO9660
{
#region IReadOnlyFilesystem Members

    /// <inheritdoc />
    public ErrorNumber ListXAttr(string path, out List<string> xattrs)
    {
        xattrs = null;

        if(!_mounted)
            return ErrorNumber.AccessDenied;

        ErrorNumber err = GetFileEntry(path, out DecodedDirectoryEntry entry);

        if(err != ErrorNumber.NoError)
            return err;

        xattrs = new List<string>();

        if(entry.XattrLength > 0)
            xattrs.Add("org.iso.9660.ea");

        if(entry.AssociatedFile != null)
            xattrs.Add("org.iso.9660.AssociatedFile");

        if(entry.AppleDosType is not null)
            xattrs.Add("com.apple.dos.type");

        if(entry.AppleProDosType is not null)
            xattrs.Add("com.apple.prodos.type");

        if(entry.ResourceFork != null)
            xattrs.Add("com.apple.ResourceFork");

        if(entry.FinderInfo != null)
            xattrs.Add("com.apple.FinderInfo");

        if(entry.AppleIcon != null)
            xattrs.Add("com.apple.Macintosh.Icon");

        if(entry.AmigaComment != null)
            xattrs.Add("com.amiga.comments");

        if(entry.Flags.HasFlag(FileFlags.Directory) || entry.Extents == null || entry.Extents.Count == 0)
            return ErrorNumber.NoError;

        ErrorNumber errno = _image.ReadSectorLong(entry.Extents[0].extent * _blockSize / 2048, out byte[] sector);

        if(errno != ErrorNumber.NoError)
            return errno;

        if(sector[15] != 2)
            return ErrorNumber.NoError;

        xattrs.Add("org.iso.mode2.subheader");
        xattrs.Add("org.iso.mode2.subheader.copy");

        return ErrorNumber.NoError;
    }

    /// <inheritdoc />
    public ErrorNumber GetXattr(string path, string xattr, ref byte[] buf)
    {
        buf = null;

        if(!_mounted)
            return ErrorNumber.AccessDenied;

        ErrorNumber err = GetFileEntry(path, out DecodedDirectoryEntry entry);

        if(err != ErrorNumber.NoError)
            return err;

        switch(xattr)
        {
            case "org.iso.9660.ea":
                return entry.XattrLength == 0 ? ErrorNumber.NoSuchExtendedAttribute :
                       entry.Extents is null  ? ErrorNumber.InvalidArgument :
                                                ReadSingleExtent(entry.XattrLength * _blockSize,
                                                                 entry.Extents[0].extent,
                                                                 out buf);

            case "org.iso.9660.AssociatedFile":
                if(entry.AssociatedFile is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                if(entry.AssociatedFile.Extents is null)
                    return ErrorNumber.InvalidArgument;

                if(entry.AssociatedFile.Size != 0)
                {
                    return ReadWithExtents(0, (long)entry.AssociatedFile.Size, entry.AssociatedFile.Extents,
                                           entry.AssociatedFile.XA?.signature == XA_MAGIC &&
                                           entry.AssociatedFile.XA?.attributes.HasFlag(XaAttributes.Interleaved) ==
                                           true, entry.AssociatedFile.XA?.filenumber ?? 0, out buf);
                }

                buf = Array.Empty<byte>();

                return ErrorNumber.NoError;

            case "com.apple.dos.type":
                if(entry.AppleDosType is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                buf    = new byte[1];
                buf[0] = entry.AppleDosType.Value;

                return ErrorNumber.NoError;
            case "com.apple.prodos.type":
                if(entry.AppleProDosType is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                buf = BitConverter.GetBytes(entry.AppleProDosType.Value);

                return ErrorNumber.NoError;
            case "com.apple.ResourceFork":
                if(entry.ResourceFork is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                if(entry.ResourceFork.Extents is null)
                    return ErrorNumber.InvalidArgument;

                if(entry.ResourceFork.Size != 0)
                {
                    return ReadWithExtents(0, (long)entry.ResourceFork.Size, entry.ResourceFork.Extents,
                                           entry.ResourceFork.XA?.signature == XA_MAGIC &&
                                           entry.ResourceFork.XA?.attributes.HasFlag(XaAttributes.Interleaved) == true,
                                           entry.ResourceFork.XA?.filenumber ?? 0, out buf);
                }

                buf = Array.Empty<byte>();

                return ErrorNumber.NoError;

            case "com.apple.FinderInfo":
                if(entry.FinderInfo is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                buf = Marshal.StructureToByteArrayBigEndian(entry.FinderInfo.Value);

                return ErrorNumber.NoError;
            case "com.apple.Macintosh.Icon":
                if(entry.AppleIcon is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                buf = new byte[entry.AppleIcon.Length];
                Array.Copy(entry.AppleIcon, 0, buf, 0, entry.AppleIcon.Length);

                return ErrorNumber.NoError;
            case "com.amiga.comments":
                if(entry.AmigaComment is null)
                    return ErrorNumber.NoSuchExtendedAttribute;

                buf = new byte[entry.AmigaComment.Length];
                Array.Copy(entry.AmigaComment, 0, buf, 0, entry.AmigaComment.Length);

                return ErrorNumber.NoError;
            case "org.iso.mode2.subheader":
                buf = ReadSubheaderWithExtents(entry.Extents, false);

                return ErrorNumber.NoError;
            case "org.iso.mode2.subheader.copy":
                buf = ReadSubheaderWithExtents(entry.Extents, true);

                return ErrorNumber.NoError;
            default:
                return ErrorNumber.NoSuchExtendedAttribute;
        }
    }

#endregion
}