Aaru/Aaru.Filesystems/UNICOS.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// 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 © 2011-2023 Natalia Portillo
// ****************************************************************************/

// UNICOS is ILP64 so let's think everything is 64-bit

using System;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using System.Text;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Console;
using Aaru.Helpers;
using Schemas;
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 Marshal = Aaru.Helpers.Marshal;
using time_t = System.Int64;

namespace Aaru.Filesystems;

/// <inheritdoc />
/// <summary>Implements detection for the Cray UNICOS filesystem</summary>
public sealed class UNICOS : IFilesystem
{
    const int NC1_MAXPART = 64;
    const int NC1_MAXIREG = 4;

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

    const string FS_TYPE = "unicos";

    /// <inheritdoc />
    public FileSystemType XmlFsType { get; private set; }
    /// <inheritdoc />
    public Encoding Encoding { get; private set; }
    /// <inheritdoc />
    public string Name => Localization.UNICOS_Name;
    /// <inheritdoc />
    public Guid Id => new("61712F04-066C-44D5-A2A0-1E44C66B33F0");
    /// <inheritdoc />
    public string Author => Authors.NataliaPortillo;

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

        uint sbSize = (uint)(Marshal.SizeOf<Superblock>() / imagePlugin.Info.SectorSize);

        if(Marshal.SizeOf<Superblock>() % imagePlugin.Info.SectorSize != 0)
            sbSize++;

        if(partition.Start + sbSize >= partition.End)
            return false;

        ErrorNumber errno = imagePlugin.ReadSectors(partition.Start, sbSize, out byte[] sector);

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

        if(sector.Length < Marshal.SizeOf<Superblock>())
            return false;

        Superblock unicosSb = Marshal.ByteArrayToStructureBigEndian<Superblock>(sector);

        AaruConsole.DebugWriteLine("UNICOS plugin", Localization.magic_equals_0_expected_1, unicosSb.s_magic,
                                   UNICOS_MAGIC);

        return unicosSb.s_magic == UNICOS_MAGIC;
    }

    /// <inheritdoc />
    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;

        uint sbSize = (uint)(Marshal.SizeOf<Superblock>() / imagePlugin.Info.SectorSize);

        if(Marshal.SizeOf<Superblock>() % imagePlugin.Info.SectorSize != 0)
            sbSize++;

        ErrorNumber errno = imagePlugin.ReadSectors(partition.Start, sbSize, out byte[] sector);

        if(errno != ErrorNumber.NoError)
            return;

        if(sector.Length < Marshal.SizeOf<Superblock>())
            return;

        Superblock unicosSb = Marshal.ByteArrayToStructureBigEndian<Superblock>(sector);

        if(unicosSb.s_magic != UNICOS_MAGIC)
            return;

        var sb = new StringBuilder();

        sb.AppendLine(Localization.UNICOS_filesystem);

        if(unicosSb.s_secure == UNICOS_SECURE)
            sb.AppendLine(Localization.Volume_is_secure);

        sb.AppendFormat(Localization.Volume_contains_0_partitions, unicosSb.s_npart).AppendLine();
        sb.AppendFormat(Localization._0_bytes_per_sector, unicosSb.s_iounit).AppendLine();
        sb.AppendLine(Localization._4096_bytes_per_block);
        sb.AppendFormat(Localization._0_data_blocks_in_volume, unicosSb.s_fsize).AppendLine();
        sb.AppendFormat(Localization.Root_resides_on_inode_0, unicosSb.s_root).AppendLine();
        sb.AppendFormat(Localization._0_inodes_in_volume, unicosSb.s_isize).AppendLine();

        sb.AppendFormat(Localization.Volume_last_updated_on_0, DateHandlers.UnixToDateTime(unicosSb.s_time)).
           AppendLine();

        if(unicosSb.s_error > 0)
            sb.AppendFormat(Localization.Volume_is_dirty_error_code_equals_0, unicosSb.s_error).AppendLine();

        sb.AppendFormat(Localization.Volume_name_0, StringHandlers.CToString(unicosSb.s_fname, Encoding)).AppendLine();

        information = sb.ToString();

        XmlFsType = new FileSystemType
        {
            Type                      = FS_TYPE,
            ClusterSize               = 4096,
            Clusters                  = (ulong)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")]
    readonly struct nc1ireg_sb
    {
        public readonly ushort i_unused; /* reserved */
        public readonly ushort i_nblk;   /* number of blocks */
        public readonly uint   i_sblk;   /* start block number */
    }

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

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

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