Aaru/DiscImageChef.Filesystems/XFS.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : XFS.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : XFS filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies the XFS filesystem and shows information.
//
// --[ 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;
using System.Runtime.InteropServices;
using System.Text;
using DiscImageChef.CommonTypes;
using DiscImageChef.CommonTypes.Enums;
using DiscImageChef.CommonTypes.Interfaces;
using DiscImageChef.Console;
using Schemas;

namespace DiscImageChef.Filesystems
{
    public class XFS : IFilesystem
    {
        const uint XFS_MAGIC = 0x58465342;

        public FileSystemType XmlFsType { get; private set; }
        public Encoding       Encoding  { get; private set; }
        public string         Name      => "XFS Filesystem Plugin";
        public Guid           Id        => new Guid("1D8CD8B8-27E6-410F-9973-D16409225FBA");
        public string         Author    => "Natalia Portillo";

        public bool Identify(IMediaImage imagePlugin, Partition partition)
        {
            if(imagePlugin.Info.SectorSize < 512) return false;

            // Misaligned
            if(imagePlugin.Info.XmlMediaType == XmlMediaType.OpticalDisc)
            {
                XFS_Superblock xfsSb = new XFS_Superblock();

                uint sbSize = (uint)((Marshal.SizeOf(xfsSb) + 0x400) / imagePlugin.Info.SectorSize);
                if((Marshal.SizeOf(xfsSb) + 0x400) % imagePlugin.Info.SectorSize != 0) sbSize++;

                byte[] sector = imagePlugin.ReadSectors(partition.Start, sbSize);
                if(sector.Length < Marshal.SizeOf(xfsSb)) return false;

                byte[] sbpiece = new byte[Marshal.SizeOf(xfsSb)];

                foreach(int location in new[] {0, 0x200, 0x400})
                {
                    Array.Copy(sector, location, sbpiece, 0, Marshal.SizeOf(xfsSb));

                    xfsSb = BigEndianMarshal.ByteArrayToStructureBigEndian<XFS_Superblock>(sbpiece);

                    DicConsole.DebugWriteLine("XFS plugin", "magic at 0x{0:X3} = 0x{1:X8} (expected 0x{2:X8})",
                                              location, xfsSb.magicnum, XFS_MAGIC);

                    if(xfsSb.magicnum == XFS_MAGIC) return true;
                }
            }
            else
                foreach(int i in new[] {0, 1, 2})
                {
                    ulong          location = (ulong)i;
                    XFS_Superblock xfsSb    = new XFS_Superblock();

                    uint sbSize = (uint)(Marshal.SizeOf(xfsSb) / imagePlugin.Info.SectorSize);
                    if(Marshal.SizeOf(xfsSb) % imagePlugin.Info.SectorSize != 0) sbSize++;

                    byte[] sector = imagePlugin.ReadSectors(partition.Start + location, sbSize);
                    if(sector.Length < Marshal.SizeOf(xfsSb)) return false;

                    xfsSb = BigEndianMarshal.ByteArrayToStructureBigEndian<XFS_Superblock>(sector);

                    DicConsole.DebugWriteLine("XFS plugin", "magic at {0} = 0x{1:X8} (expected 0x{2:X8})", location,
                                              xfsSb.magicnum, XFS_MAGIC);

                    if(xfsSb.magicnum == XFS_MAGIC) return true;
                }

            return false;
        }

        public void GetInformation(IMediaImage imagePlugin, Partition partition, out string information,
                                   Encoding    encoding)
        {
            Encoding    = encoding ?? Encoding.GetEncoding("iso-8859-15");
            information = "";
            if(imagePlugin.Info.SectorSize < 512) return;

            XFS_Superblock xfsSb = new XFS_Superblock();

            // Misaligned
            if(imagePlugin.Info.XmlMediaType == XmlMediaType.OpticalDisc)
            {
                uint sbSize = (uint)((Marshal.SizeOf(xfsSb) + 0x400) / imagePlugin.Info.SectorSize);
                if((Marshal.SizeOf(xfsSb) + 0x400) % imagePlugin.Info.SectorSize != 0) sbSize++;

                byte[] sector = imagePlugin.ReadSectors(partition.Start, sbSize);
                if(sector.Length < Marshal.SizeOf(xfsSb)) return;

                byte[] sbpiece = new byte[Marshal.SizeOf(xfsSb)];

                foreach(int location in new[] {0, 0x200, 0x400})
                {
                    Array.Copy(sector, location, sbpiece, 0, Marshal.SizeOf(xfsSb));

                    xfsSb = BigEndianMarshal.ByteArrayToStructureBigEndian<XFS_Superblock>(sbpiece);

                    DicConsole.DebugWriteLine("XFS plugin", "magic at 0x{0:X3} = 0x{1:X8} (expected 0x{2:X8})",
                                              location, xfsSb.magicnum, XFS_MAGIC);

                    if(xfsSb.magicnum == XFS_MAGIC) break;
                }
            }
            else
                foreach(int i in new[] {0, 1, 2})
                {
                    ulong location = (ulong)i;
                    uint  sbSize   = (uint)(Marshal.SizeOf(xfsSb) / imagePlugin.Info.SectorSize);
                    if(Marshal.SizeOf(xfsSb) % imagePlugin.Info.SectorSize != 0) sbSize++;

                    byte[] sector = imagePlugin.ReadSectors(partition.Start + location, sbSize);
                    if(sector.Length < Marshal.SizeOf(xfsSb)) return;

                    xfsSb = BigEndianMarshal.ByteArrayToStructureBigEndian<XFS_Superblock>(sector);

                    DicConsole.DebugWriteLine("XFS plugin", "magic at {0} = 0x{1:X8} (expected 0x{2:X8})", location,
                                              xfsSb.magicnum, XFS_MAGIC);

                    if(xfsSb.magicnum == XFS_MAGIC) break;
                }

            if(xfsSb.magicnum != XFS_MAGIC) return;

            StringBuilder sb = new StringBuilder();

            sb.AppendLine("XFS filesystem");
            sb.AppendFormat("Filesystem version {0}", xfsSb.version & 0xF).AppendLine();
            sb.AppendFormat("{0} bytes per sector", xfsSb.sectsize).AppendLine();
            sb.AppendFormat("{0} bytes per block", xfsSb.blocksize).AppendLine();
            sb.AppendFormat("{0} bytes per inode", xfsSb.inodesize).AppendLine();
            sb.AppendFormat("{0} data blocks in volume, {1} free", xfsSb.dblocks, xfsSb.fdblocks).AppendLine();
            sb.AppendFormat("{0} blocks per allocation group", xfsSb.agblocks).AppendLine();
            sb.AppendFormat("{0} allocation groups in volume", xfsSb.agcount).AppendLine();
            sb.AppendFormat("{0} inodes in volume, {1} free", xfsSb.icount, xfsSb.ifree).AppendLine();
            if(xfsSb.inprogress > 0) sb.AppendLine("fsck in progress");
            sb.AppendFormat("Volume name: {0}", StringHandlers.CToString(xfsSb.fname, Encoding)).AppendLine();
            sb.AppendFormat("Volume UUID: {0}", xfsSb.uuid).AppendLine();

            information = sb.ToString();

            XmlFsType = new FileSystemType
            {
                Type                  = "XFS filesystem",
                ClusterSize           = (int)xfsSb.blocksize,
                Clusters              = (long)xfsSb.dblocks,
                FreeClusters          = (long)xfsSb.fdblocks,
                FreeClustersSpecified = true,
                Files                 = (long)(xfsSb.icount - xfsSb.ifree),
                FilesSpecified        = true,
                Dirty                 = xfsSb.inprogress > 0,
                VolumeName            = StringHandlers.CToString(xfsSb.fname, Encoding),
                VolumeSerial          = xfsSb.uuid.ToString()
            };
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        struct XFS_Superblock
        {
            public uint   magicnum;
            public uint   blocksize;
            public ulong  dblocks;
            public ulong  rblocks;
            public ulong  rextents;
            public Guid   uuid;
            public ulong  logstat;
            public ulong  rootino;
            public ulong  rbmino;
            public ulong  rsumino;
            public uint   rextsize;
            public uint   agblocks;
            public uint   agcount;
            public uint   rbmblocks;
            public uint   logblocks;
            public ushort version;
            public ushort sectsize;
            public ushort inodesize;
            public ushort inopblock;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
            public byte[] fname;
            public byte   blocklog;
            public byte   sectlog;
            public byte   inodelog;
            public byte   inopblog;
            public byte   agblklog;
            public byte   rextslog;
            public byte   inprogress;
            public byte   imax_pct;
            public ulong  icount;
            public ulong  ifree;
            public ulong  fdblocks;
            public ulong  frextents;
            public ulong  uquotino;
            public ulong  gquotino;
            public ushort qflags;
            public byte   flags;
            public byte   shared_vn;
            public ulong  inoalignmt;
            public ulong  unit;
            public ulong  width;
            public byte   dirblklog;
            public byte   logsectlog;
            public ushort logsectsize;
            public uint   logsunit;
            public uint   features2;
            public uint   bad_features2;
            public uint   features_compat;
            public uint   features_ro_compat;
            public uint   features_incompat;
            public uint   features_log_incompat;
            // This field is little-endian while rest of superblock is big-endian
            public uint  crc;
            public uint  spino_align;
            public ulong pquotino;
            public ulong lsn;
            public Guid  meta_uuid;
        }
    }
}