Fix loading from older SDKs & use faster CAB search code

emoose · Feb 1, 2020 · 9bcf35f · 9bcf35f
1 parent b7dc6c2
commit 9bcf35f
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Showing 8 changed files with 75 additions and 52 deletions.
diff --git a/XbRecUnpack/CabFile.cs b/XbRecUnpack/CabFile.cs
@@ -1,11 +1,10 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Runtime.InteropServices;
 using System.IO;
 
+// TODO: this doesn't support cabs that use multiple CFFOLDERS (if any do)
+// Also only supports LZX compression, there's code to support non-compressed data too but it's untested
 namespace XbRecUnpack
 {
     [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]

diff --git a/XbRecUnpack/LzxDecoder.cs b/XbRecUnpack/LzxDecoder.cs
@@ -50,9 +50,6 @@
 #endregion
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.IO;
 
 namespace XbRecUnpack

diff --git a/XbRecUnpack/Program.cs b/XbRecUnpack/Program.cs
@@ -4,8 +4,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.IO;
 using System.IO.Compression;
 using DiscUtils.Iso9660;

diff --git a/XbRecUnpack/RecoveryControlFile.cs b/XbRecUnpack/RecoveryControlFile.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Text;
 using System.IO;
 
 namespace XbRecUnpack

diff --git a/XbRecUnpack/RemoteRecovery.cs b/XbRecUnpack/RemoteRecovery.cs
@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using System.IO;
 
 namespace XbRecUnpack
@@ -60,17 +58,24 @@ public bool Read()
 
             Console.WriteLine("Scanning EXE...");
             cabHeaderPos = new List<long>();
-            while(reader.BaseStream.Position + 8 < reader.BaseStream.Length)
+
+            // Track position/length ourselves instead of needing to call stream accessors
+            long position = reader.BaseStream.Position;
+            long length = reader.BaseStream.Length;
+
+            // Fast pattern search via sliding-window, kinda
+            // From https://codereview.stackexchange.com/questions/202235/finding-specific-small-byte-arrays-in-large-binary-files
+            ulong pattern = ((ulong)0x4643534D).EndianSwap();
+            ulong view = 0;
+            long viewed = 0;
+
+            while (position + 8 < length)
             {
-                var currentPos = reader.BaseStream.Position;
-                if (reader.ReadUInt64() == 0x4643534D)
-                {
-                    cabHeaderPos.Add(currentPos);
-                    var size = reader.ReadUInt32();
-                    reader.BaseStream.Position += (size - 0xC);
-                }
-                else
-                    reader.BaseStream.Position = currentPos + 1;
+                view = (view << 8) | reader.ReadByte() ; // shift-in next byte
+                position++;
+                viewed++;
+                if (view == pattern && viewed >= 8) // make sure we already got at least 4 bytes
+                    cabHeaderPos.Add(position - 8);
             }
 
             if (cabHeaderPos.Count < 2)
@@ -79,36 +84,50 @@ public bool Read()
                 return false;
             }
 
+            string[] csv = null;
             // Read the second cab in the file, contains some meta info about the other ones
-            reader.BaseStream.Position = cabHeaderPos[1];
-            var metaCab = new CabFile(reader.BaseStream);
-            if (!metaCab.Read())
+            while (cabHeaderPos.Count > 1)
             {
-                Console.WriteLine("Error: failed to read meta-cab!");
-                return false;
-            }
+                reader.BaseStream.Position = cabHeaderPos[1];
 
-            // Remove the meta cab from cab header list...
-            cabHeaderPos.RemoveAt(1);
+                // Remove the meta cab from cab header list...
+                cabHeaderPos.RemoveAt(1);
 
-            // Read the manifest file...
-            var manifest = new CFFILE();
-            if (!metaCab.GetEntry("manifest.csv", ref manifest, false))
-            {
-                Console.WriteLine("Error: failed to find manifest.csv inside meta-cab!");
-                return false;
-            }
+                // Try reading metacab
+                var metaCab = new CabFile(reader.BaseStream);
+                if (!metaCab.Read())
+                    continue;
 
-            var manifestStream = metaCab.OpenFile(manifest);
-            if (manifestStream == null)
-                return false;
+                // Read the manifest file...
+                var manifest = new CFFILE();
+                if (!metaCab.GetEntry("manifest.csv", ref manifest, false))
+                    continue;
+
+                Stream manifestStream = null;
+                try
+                {
+                    manifestStream = metaCab.OpenFile(manifest);
+                    if (manifestStream == null)
+                        continue;
+                }
+                catch
+                {
+                    continue;
+                }
+
+                using (var reader2 = new BinaryReader(manifestStream))
+                {
+                    byte[] data = reader2.ReadBytes((int)reader2.BaseStream.Length);
+                    var str = Encoding.ASCII.GetString(data);
+                    csv = str.Replace("\r\n", "\n").Split(new char[] { '\n' });
+                }
+                break;
+            }
 
-            string[] csv;
-            using (var reader2 = new BinaryReader(manifestStream))
+            if(csv == null)
             {
-                byte[] data = reader2.ReadBytes((int)reader2.BaseStream.Length);
-                var str = Encoding.ASCII.GetString(data);
-                csv = str.Replace("\r\n", "\n").Split(new char[]{ '\n' });
+                Console.WriteLine("Error: failed to read manifest.csv from meta-cab section!");
+                return false;
             }
 
             Variants = new List<string>();
@@ -118,10 +137,14 @@ public bool Read()
                 if (string.IsNullOrEmpty(line))
                     continue;
 
-                var parts = line.Split(new char[] { ',' });
-                if (parts.Length < 6)
+                var parts = new List<string>(line.Split(new char[] { ',' }));
+                if (parts.Count < 6)
                     continue;
 
+                // Older SDKs don't have a variant section, so we'll insert one
+                if (parts[1] == "file" || parts[1] == "copy" || parts[1] == "sharedfile" || parts[1] == "backupsharedfile" || parts[1] == "singlefile")
+                    parts.Insert(1, "");
+
                 if (parts[2] != "file" && parts[2] != "copy" && parts[2] != "sharedfile" && parts[2] != "backupsharedfile" && parts[2] != "singlefile")
                     continue;
 
@@ -275,6 +298,12 @@ public bool Extract(string destDirPath, bool listOnly = false)
                 totalIndex++;
             }
 
+            if (mainCab.Entries.Count > cabIndex)
+            {
+                var diff = mainCab.Entries.Count - cabIndex;
+                Console.WriteLine($"Note: CAB contains {diff} more file{(diff == 1 ? "" : "s")} than were inside the manifest!");
+            }
+
             return true;
         }
     }

diff --git a/XbRecUnpack/XbRecUnpack.csproj b/XbRecUnpack/XbRecUnpack.csproj
@@ -5,6 +5,12 @@
     <TargetFrameworks>net472</TargetFrameworks>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Release|net472|AnyCPU'">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>none</DebugType>
+    <DebugSymbols>false</DebugSymbols>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Discutils" Version="0.11.0.2" />
   </ItemGroup>

diff --git a/XbRecUnpack/XboxGDFImage.cs b/XbRecUnpack/XboxGDFImage.cs
@@ -2,10 +2,10 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 using System.IO;
 using System.Runtime.InteropServices;
 
+// NOTE: Only tested with Xbox OG recovery ISOs, games & X360 ISOs likely won't work well with it
 namespace XbRecUnpack
 {
     [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
@@ -237,5 +237,4 @@ public override void Close()
             source.Close();
         }
     }
-
 }
diff --git a/XbRecUnpack/XboxRom.cs b/XbRecUnpack/XboxRom.cs
@@ -1,8 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.IO;
 using System.Runtime.InteropServices;
 namespace XbRecUnpack