Add a lightweight MSCab parser.

OpenRA.Mods.Common/FileFormats/MSCabCompression.cs

@@ -0,0 +1,131 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2016 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using ICSharpCode.SharpZipLib.Zip.Compression;
+using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
+
+namespace OpenRA.Mods.Common.FileFormats
+{
+	public sealed class MSCabCompression
+	{
+		class CabFolder
+		{
+			public readonly uint BlockOffset;
+			public readonly ushort BlockCount;
+			public readonly ushort CompressionType;
+
+			public CabFolder(Stream stream)
+			{
+				BlockOffset = stream.ReadUInt32();
+				BlockCount = stream.ReadUInt16();
+				CompressionType = stream.ReadUInt16();
+			}
+		}
+
+		class CabFile
+		{
+			public readonly string FileName;
+			public readonly uint DecompressedLength;
+			public readonly uint DecompressedOffset;
+			public readonly ushort FolderIndex;
+
+			public CabFile(Stream stream)
+			{
+				DecompressedLength = stream.ReadUInt32();
+				DecompressedOffset = stream.ReadUInt32();
+				FolderIndex = stream.ReadUInt16();
+				stream.Position += 6;
+				FileName = stream.ReadASCIIZ();
+			}
+		}
+
+		readonly CabFolder[] folders;
+		readonly CabFile[] files;
+		readonly Stream stream;
+
+		public MSCabCompression(Stream stream)
+		{
+			this.stream = stream;
+
+			var signature = stream.ReadASCII(4);
+			if (signature != "MSCF")
+				throw new InvalidDataException("Not a Microsoft CAB package!");
+
+			stream.Position += 12;
+			var filesOffset = stream.ReadUInt32();
+			stream.Position += 6;
+			var folderCount = stream.ReadUInt16();
+			var fileCount = stream.ReadUInt16();
+			if (stream.ReadUInt16() != 0)
+				throw new InvalidDataException("Only plain packages (without reserved header space or prev/next archives) are supported!");
+
+			stream.Position += 4;
+
+			folders = new CabFolder[folderCount];
+			for (var i = 0; i < folderCount; i++)
+			{
+				folders[i] = new CabFolder(stream);
+				if (folders[i].CompressionType != 1)
+					throw new InvalidDataException("Compression type is not supported");
+			}
+
+			files = new CabFile[fileCount];
+			stream.Seek(filesOffset, SeekOrigin.Begin);
+			for (var i = 0; i < fileCount; i++)
+				files[i] = new CabFile(stream);
+		}
+
+		public byte[] ExtractFile(string filename, Action<int> onProgress = null)
+		{
+			var file = files.FirstOrDefault(f => f.FileName == filename);
+			if (file == null)
+				return null;
+
+			var folder = folders[file.FolderIndex];
+			stream.Seek(folder.BlockOffset, SeekOrigin.Begin);
+
+			using (var outputStream = new MemoryStream())
+			{
+				var inflater = new Inflater(true);
+				var buffer = new byte[4096];
+				for (var i = 0; i < folder.BlockCount; i++)
+				{
+					if (onProgress != null)
+						onProgress((int)(100 * outputStream.Position / file.DecompressedLength));
+
+					// Ignore checksums
+					stream.Position += 4;
+					var blockLength = stream.ReadUInt16();
+					stream.Position += 4;
+
+					using (var batch = new MemoryStream(stream.ReadBytes(blockLength - 2)))
+					using (var inflaterStream = new InflaterInputStream(batch, inflater))
+					{
+						int n;
+						while ((n = inflaterStream.Read(buffer, 0, buffer.Length)) > 0)
+							outputStream.Write(buffer, 0, n);
+					}
+
+					inflater.Reset();
+				}
+
+				outputStream.Seek(file.DecompressedOffset, SeekOrigin.Begin);
+				return outputStream.ReadBytes((int)file.DecompressedLength);
+			}
+		}
+
+		public IEnumerable<string> Contents { get { return files.Select(f => f.FileName); } }
+	}
+}

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -753,6 +753,8 @@
     <Compile Include="AI\DummyAI.cs" />
     <Compile Include="UtilityCommands\ListInstallShieldContentsCommand.cs" />
     <Compile Include="UtilityCommands\ListMixContentsCommand.cs" />
+    <Compile Include="UtilityCommands\ListMSCabContentsCommand.cs" />
+    <Compile Include="FileFormats\MSCabCompression.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>

OpenRA.Mods.Common/UtilityCommands/ListMSCabContentsCommand.cs

@@ -0,0 +1,35 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2016 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.IO;
+using OpenRA.Mods.Common.FileFormats;
+
+namespace OpenRA.Mods.Common.UtilityCommands
+{
+	class ListMSCabContentsCommand : IUtilityCommand
+	{
+		public string Name { get { return "--list-mscab"; } }
+
+		public bool ValidateArguments(string[] args)
+		{
+			return args.Length == 2;
+		}
+
+		[Desc("ARCHIVE.CAB", "Lists the filenames contained within a MSCAB file")]
+		public void Run(ModData modData, string[] args)
+		{
+			var package = new MSCabCompression(File.OpenRead(args[1]));
+			foreach (var file in package.Contents)
+				Console.WriteLine("{0}", file);
+		}
+	}
+}