Aaru/DiscImageChef.Filesystems/AppleMFS/File.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : File.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Apple Macintosh File System plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Methods to handle files.
//
// --[ 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.IO;
using DiscImageChef.Console;

namespace DiscImageChef.Filesystems.AppleMFS
{
    // Information from Inside Macintosh Volume II
    public partial class AppleMFS : Filesystem
    {
        public override Errno MapBlock(string path, long fileBlock, ref long deviceBlock)
        {
            deviceBlock = new long();

            if(!mounted)
                return Errno.AccessDenied;

            string[] pathElements = path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            if(pathElements.Length != 1)
                return Errno.NotSupported;

            uint fileID;
            MFS_FileEntry entry;

            if(!filenameToId.TryGetValue(path.ToLowerInvariant(), out fileID))
                return Errno.NoSuchFile;

            if(!idToEntry.TryGetValue(fileID, out entry))
                return Errno.NoSuchFile;

            if(fileBlock > (entry.flPyLen / volMDB.drAlBlkSiz))
                return Errno.InvalidArgument;

            uint nextBlock = entry.flStBlk;
            long relBlock = 0;

            while(true)
            {
                if(relBlock == fileBlock)
                {
                    deviceBlock = ((nextBlock - 2) * sectorsPerBlock) + volMDB.drAlBlSt + (long)partitionStart;
                    return Errno.NoError;
                }

                if(blockMap[nextBlock] == BMAP_FREE || blockMap[nextBlock] == BMAP_LAST)
                    break;

                nextBlock = blockMap[nextBlock];
                relBlock++;
            }

            return Errno.InOutError;
        }

        public override Errno GetAttributes(string path, ref FileAttributes attributes)
        {
            if(!mounted)
                return Errno.AccessDenied;

            string[] pathElements = path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            if(pathElements.Length != 1)
                return Errno.NotSupported;

            uint fileID;
            MFS_FileEntry entry;

            if(!filenameToId.TryGetValue(path.ToLowerInvariant(), out fileID))
                return Errno.NoSuchFile;

            if(!idToEntry.TryGetValue(fileID, out entry))
                return Errno.NoSuchFile;

            attributes = new FileAttributes();
            MFS_FinderFlags fdFlags = (MFS_FinderFlags)BigEndianBitConverter.ToUInt16(entry.flUsrWds, 0x08);

            if(fdFlags.HasFlag(MFS_FinderFlags.kIsAlias))
                attributes |= FileAttributes.Alias;
            if(fdFlags.HasFlag(MFS_FinderFlags.kHasBundle))
                attributes |= FileAttributes.Bundle;
            if(fdFlags.HasFlag(MFS_FinderFlags.kHasBeenInited))
                attributes |= FileAttributes.HasBeenInited;
            if(fdFlags.HasFlag(MFS_FinderFlags.kHasCustomIcon))
                attributes |= FileAttributes.HasCustomIcon;
            if(fdFlags.HasFlag(MFS_FinderFlags.kHasNoINITs))
                attributes |= FileAttributes.HasNoINITs;
            if(fdFlags.HasFlag(MFS_FinderFlags.kIsInvisible))
                attributes |= FileAttributes.Hidden;
            if(entry.flFlags.HasFlag(MFS_FileFlags.Locked))
                attributes |= FileAttributes.Immutable;
            if(fdFlags.HasFlag(MFS_FinderFlags.kIsOnDesk))
                attributes |= FileAttributes.IsOnDesk;
            if(fdFlags.HasFlag(MFS_FinderFlags.kIsShared))
                attributes |= FileAttributes.Shared;
            if(fdFlags.HasFlag(MFS_FinderFlags.kIsStationery))
                attributes |= FileAttributes.Stationery;

            if(!attributes.HasFlag(FileAttributes.Alias) &&
               !attributes.HasFlag(FileAttributes.Bundle) &&
               !attributes.HasFlag(FileAttributes.Stationery))
                attributes |= FileAttributes.File;

            attributes |= FileAttributes.BlockUnits;
            
            return Errno.NoError;
        }

        public override Errno Read(string path, long offset, long size, ref byte[] buf)
        {
            if(!mounted)
                return Errno.AccessDenied;

            byte[] file;
            Errno error = Errno.NoError;

            if(debug && string.Compare(path, "$", StringComparison.InvariantCulture) == 0)
                file = directoryBlocks;
            else if(debug && string.Compare(path, "$Boot", StringComparison.InvariantCulture) == 0 && bootBlocks != null)
                file = bootBlocks;
            else if(debug && string.Compare(path, "$Bitmap", StringComparison.InvariantCulture) == 0)
                file = blockMapBytes;
            else if(debug && string.Compare(path, "$MDB", StringComparison.InvariantCulture) == 0)
                file = mdbBlocks;
            else
                error = ReadFile(path, out file, false, false);
            
            if(error != Errno.NoError)
                return error;

            if(size == 0)
            {
                buf = new byte[0];
                return Errno.NoError;
            }

            if(offset >= file.Length)
                return Errno.InvalidArgument;

            if(size + offset >= file.Length)
                size = file.Length - offset;

            buf = new byte[size];

            Array.Copy(file, offset, buf, 0, size);

            return Errno.NoError;
        }

        public override Errno Stat(string path, ref FileEntryInfo stat)
        {
            if(!mounted)
                return Errno.AccessDenied;

            string[] pathElements = path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            if(pathElements.Length != 1)
                return Errno.NotSupported;

            if(debug)
            {
                if(string.Compare(path, "$", StringComparison.InvariantCulture) == 0 ||
                   string.Compare(path, "$Boot", StringComparison.InvariantCulture) == 0 ||
                   string.Compare(path, "$Bitmap", StringComparison.InvariantCulture) == 0 ||
                   string.Compare(path, "$MDB", StringComparison.InvariantCulture) == 0)
                {
                    stat = new FileEntryInfo();
                    stat.Attributes = new FileAttributes();
                    stat.Attributes = FileAttributes.System;
                    stat.BlockSize = device.GetSectorSize();
                    stat.DeviceNo = 0;
                    stat.GID = 0;
                    stat.Inode = 0;
                    stat.Links = 1;
                    stat.Mode = 0x124;
                    stat.UID = 0;

                    if(string.Compare(path, "$", StringComparison.InvariantCulture) == 0)
                    {
                        stat.Blocks = (directoryBlocks.Length / stat.BlockSize) + (directoryBlocks.Length % stat.BlockSize);
                        stat.Length = directoryBlocks.Length;
                    }
                    else if(string.Compare(path, "$Bitmap", StringComparison.InvariantCulture) == 0)
                    {
                        stat.Blocks = (blockMapBytes.Length / stat.BlockSize) + (blockMapBytes.Length % stat.BlockSize);
                        stat.Length = blockMapBytes.Length;
                    }
                    else if(string.Compare(path, "$Boot", StringComparison.InvariantCulture) == 0 && bootBlocks != null)
                    {
                        stat.Blocks = (bootBlocks.Length / stat.BlockSize) + (bootBlocks.Length % stat.BlockSize);
                        stat.Length = bootBlocks.Length;
                    }
                    else if(string.Compare(path, "$MDB", StringComparison.InvariantCulture) == 0)
                    {
                        stat.Blocks = (mdbBlocks.Length / stat.BlockSize) + (mdbBlocks.Length % stat.BlockSize);
                        stat.Length = mdbBlocks.Length;
                    }
                    else
                        return Errno.InvalidArgument;

                    return Errno.NoError;
                }
            }

            uint fileID;
            MFS_FileEntry entry;

            if(!filenameToId.TryGetValue(path.ToLowerInvariant(), out fileID))
                return Errno.NoSuchFile;

            if(!idToEntry.TryGetValue(fileID, out entry))
                return Errno.NoSuchFile;

            FileAttributes attr = new FileAttributes();
            Errno error = GetAttributes(path, ref attr);
            if(error != Errno.NoError)
                return error;

            stat = new FileEntryInfo();
            stat.Attributes = attr;
            stat.Blocks = entry.flLgLen / volMDB.drAlBlkSiz;
            stat.BlockSize = volMDB.drAlBlkSiz;
            stat.CreationTime = DateHandlers.MacToDateTime(entry.flCrDat);
            stat.DeviceNo = 0;
            stat.GID = 0;
            stat.Inode = entry.flFlNum;
            stat.LastWriteTime = DateHandlers.MacToDateTime(entry.flMdDat);
            stat.Length = entry.flPyLen;
            stat.Links = 1;
            stat.Mode = 0x124;
            stat.UID = 0;

            return Errno.NoError;
        }

        public override Errno ReadLink(string path, ref string dest)
        {
            return Errno.NotImplemented;
        }

        Errno ReadFile(string path, out byte[] buf, bool resourceFork, bool tags)
        {
            buf = null;

            if(!mounted)
                return Errno.AccessDenied;

            string[] pathElements = path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            if(pathElements.Length != 1)
                return Errno.NotSupported;

            uint fileID;
            MFS_FileEntry entry;

            if(!filenameToId.TryGetValue(path.ToLowerInvariant(), out fileID))
                return Errno.NoSuchFile;

            if(!idToEntry.TryGetValue(fileID, out entry))
                return Errno.NoSuchFile;

            uint nextBlock;

            if(resourceFork)
            {
                if(entry.flRPyLen == 0)
                {
                    buf = new byte[0];
                    return Errno.NoError;
                }
                nextBlock = entry.flRStBlk;
            }
            else
            {
                if(entry.flPyLen == 0)
                {
                    buf = new byte[0];
                    return Errno.NoError;
                }

                nextBlock = entry.flStBlk;
            }

            MemoryStream ms = new MemoryStream();
            byte[] sectors;

            do
            {
                if(tags)
                    sectors = device.ReadSectorsTag((ulong)((nextBlock - 2) * sectorsPerBlock) + volMDB.drAlBlSt + partitionStart, (uint)sectorsPerBlock, ImagePlugins.SectorTagType.AppleSectorTag);
                else
                    sectors = device.ReadSectors((ulong)((nextBlock - 2) * sectorsPerBlock) + volMDB.drAlBlSt + partitionStart, (uint)sectorsPerBlock);

                ms.Write(sectors, 0, sectors.Length);

                if(blockMap[nextBlock] == BMAP_FREE)
                {
                    DicConsole.ErrorWriteLine("File truncated at block {0}", nextBlock);
                    break;
                }

                nextBlock = blockMap[nextBlock];
            }
            while(nextBlock > BMAP_LAST);

            if(tags)
                buf = ms.ToArray();
            else
            {
                if(resourceFork)
                {
                    if(ms.Length < entry.flRLgLen)
                        buf = ms.ToArray();
                    else
                    {
                        buf = new byte[entry.flRLgLen];
                        Array.Copy(ms.ToArray(), 0, buf, 0, buf.Length);
                    }
                }
                else
                {
                    if(ms.Length < entry.flLgLen)
                        buf = ms.ToArray();
                    else
                    {
                        buf = new byte[entry.flLgLen];
                        Array.Copy(ms.ToArray(), 0, buf, 0, buf.Length);
                    }
                }
            }

            return Errno.NoError;
        }
    }
}