Aaru/DiscImageChef.Filesystems/UNICOS.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : UNICOS.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : UNICOS filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies the UNICOS 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.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using System.Text;
using DiscImageChef.CommonTypes;
using DiscImageChef.Console;
using DiscImageChef.DiscImages;
using Schemas;
// UNICOS is ILP64 so let's think everything is 64-bit
using blkno_t = System.Int64;
using daddr_t = System.Int64;
using dev_t = System.Int64;
using extent_t = System.Int64;
using ino_t = System.Int64;
using time_t = System.Int64;

namespace DiscImageChef.Filesystems
{
    public class UNICOS : IFilesystem
    {
        const int NC1_MAXPART = 64;
        const int NC1_MAXIREG = 4;

        const ulong UNICOS_MAGIC  = 0x6e6331667331636e;
        const ulong UNICOS_SECURE = 0xcd076d1771d670cd;

        public FileSystemType XmlFsType { get; private set; }
        public Encoding       Encoding  { get; private set; }
        public string         Name      => "UNICOS Filesystem Plugin";
        public Guid           Id        => new Guid("61712F04-066C-44D5-A2A0-1E44C66B33F0");

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

            UNICOS_Superblock unicosSb = new UNICOS_Superblock();

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

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

            unicosSb = BigEndianMarshal.ByteArrayToStructureBigEndian<UNICOS_Superblock>(sector);

            DicConsole.DebugWriteLine("UNICOS plugin", "magic = 0x{0:X16} (expected 0x{1:X16})", unicosSb.s_magic,
                                      UNICOS_MAGIC);

            return unicosSb.s_magic == UNICOS_MAGIC;
        }

        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;

            UNICOS_Superblock unicosSb = new UNICOS_Superblock();

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

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

            unicosSb = BigEndianMarshal.ByteArrayToStructureBigEndian<UNICOS_Superblock>(sector);

            if(unicosSb.s_magic != UNICOS_MAGIC) return;

            StringBuilder sb = new StringBuilder();

            sb.AppendLine("UNICOS filesystem");
            if(unicosSb.s_secure == UNICOS_SECURE) sb.AppendLine("Volume is secure");
            sb.AppendFormat("Volume contains {0} partitions", unicosSb.s_npart).AppendLine();
            sb.AppendFormat("{0} bytes per sector", unicosSb.s_iounit).AppendLine();
            sb.AppendLine("4096 bytes per block");
            sb.AppendFormat("{0} data blocks in volume", unicosSb.s_fsize).AppendLine();
            sb.AppendFormat("Root resides on inode {0}", unicosSb.s_root).AppendLine();
            sb.AppendFormat("{0} inodes in volume", unicosSb.s_isize).AppendLine();
            sb.AppendFormat("Volume last updated on {0}", DateHandlers.UnixToDateTime(unicosSb.s_time)).AppendLine();
            if(unicosSb.s_error > 0)
                sb.AppendFormat("Volume is dirty, error code = 0x{0:X16}", unicosSb.s_error).AppendLine();
            sb.AppendFormat("Volume name: {0}", StringHandlers.CToString(unicosSb.s_fname, Encoding)).AppendLine();

            information = sb.ToString();

            XmlFsType = new FileSystemType
            {
                Type                      = "UNICOS filesystem",
                ClusterSize               = 4096,
                Clusters                  = unicosSb.s_fsize,
                VolumeName                = StringHandlers.CToString(unicosSb.s_fname, Encoding),
                ModificationDate          = DateHandlers.UnixToDateTime(unicosSb.s_time),
                ModificationDateSpecified = true
            };
            XmlFsType.Dirty |= unicosSb.s_error > 0;
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        [SuppressMessage("ReSharper", "InconsistentNaming")]
        struct nc1ireg_sb
        {
            public ushort i_unused; /* reserved */
            public ushort i_nblk;   /* number of blocks */
            public uint   i_sblk;   /* start block number */
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        [SuppressMessage("ReSharper", "InconsistentNaming")]
        struct nc1fdev_sb
        {
            public long fd_name; /* Physical device name */
            public uint fd_sblk; /* Start block number */
            public uint fd_nblk; /* Number of blocks */
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = NC1_MAXIREG)]
            public nc1ireg_sb[] fd_ireg; /* Inode regions */
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        [SuppressMessage("ReSharper", "InconsistentNaming")]
        [SuppressMessage("ReSharper", "BuiltInTypeReferenceStyle")]
        struct UNICOS_Superblock
        {
            public ulong s_magic; /* magic number to indicate file system type */
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public byte[] s_fname; /* file system name */
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public byte[] s_fpack; /* file system pack name */
            public dev_t s_dev;    /* major/minor device, for verification */

            public daddr_t  s_fsize;   /* size in blocks of entire volume */
            public long     s_isize;   /* Number of total inodes */
            public long     s_bigfile; /* number of bytes at which a file is big */
            public long     s_bigunit; /* minimum number of blocks allocated for big files */
            public ulong    s_secure;  /* security: secure FS label */
            public long     s_maxlvl;  /* security: maximum security level */
            public long     s_minlvl;  /* security: minimum security level */
            public long     s_valcmp;  /* security: valid security compartments */
            public time_t   s_time;    /* last super block update */
            public blkno_t  s_dboff;   /* Dynamic block number */
            public ino_t    s_root;    /* root inode */
            public long     s_error;   /* Type of file system error detected */
            public blkno_t  s_mapoff;  /* Start map block number */
            public long     s_mapblks; /* Last map block number */
            public long     s_nscpys;  /* Number of copies of s.b per partition */
            public long     s_npart;   /* Number of partitions */
            public long     s_ifract;  /* Ratio of inodes to blocks */
            public extent_t s_sfs;     /* SFS only blocks */
            public long     s_flag;    /* Flag word */
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = NC1_MAXPART)]
            public nc1fdev_sb[] s_part; /* Partition descriptors */
            public long s_iounit;       /* Physical block size */
            public long s_numiresblks;  /* number of inode reservation blocks */
            /* per region (currently 1) */
            /* 0 = 1*(AU) words, n = (n+1)*(AU) words */
            public long s_priparts; /* bitmap of primary partitions */
            public long s_priblock; /* block size of primary partition(s) */
            /* 0 = 1*512 words, n = (n+1)*512 words */
            public long s_prinblks; /* number of 512 wds blocks in primary */
            public long s_secparts; /* bitmap of secondary partitions */
            public long s_secblock; /* block size of secondary partition(s) */
            /* 0 = 1*512 words, n = (n+1)*512 words */
            public long s_secnblks;  /* number of 512 wds blocks in secondary */
            public long s_sbdbparts; /* bitmap of partitions with file system data */
            /* including super blocks, dynamic block */
            /* and free block bitmaps (only primary */
            /* partitions may contain these) */
            public long s_rootdparts; /* bitmap of partitions with root directory */
            /* (only primary partitions) */
            public long s_nudparts; /* bitmap of no-user-data partitions */
            /* (only primary partitions) */
            public long s_nsema;     /* SFS: # fs semaphores to allocate */
            public long s_priactive; /* bitmap of primary partitions which contain */
            /* active (up to date) dynamic blocks and */
            /* free block bitmaps. All bits set indicate */
            /* that all primary partitions are active, */
            /* and no kernel manipulation of active flag */
            /* is allowed. */
            public long s_sfs_arbiterid; /* SFS Arbiter ID */
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 91)]
            public long[] s_fill; /* reserved */
        }
    }
}