From 3e16aaef8ec8ffc3f15cb3d280d3f9ff6dca6182 Mon Sep 17 00:00:00 2001
From: AlexKnauth <alexander@knauth.org>
Date: Mon, 16 Oct 2023 17:33:29 -0400
Subject: [PATCH] Offsets for 64-bit MachO V1, V2

---
 src/game_engine/unity/mono.rs | 65 ++++++++++++++++++++++++++++++++---
 1 file changed, 60 insertions(+), 5 deletions(-)

diff --git a/src/game_engine/unity/mono.rs b/src/game_engine/unity/mono.rs
index b23a321..0a0683b 100644
--- a/src/game_engine/unity/mono.rs
+++ b/src/game_engine/unity/mono.rs
@@ -48,7 +48,7 @@ impl Module {
             .find_map(|&name| process.get_module_address(name).ok())?;
 
         let is_64_bit = pe::MachineType::read(process, module)? == pe::MachineType::X86_64;
-        let offsets = Offsets::new(version, is_64_bit);
+        let offsets = Offsets::new(version, is_64_bit, BinaryFormat::PE);
 
         let root_domain_function_address = pe::symbols(process, module)
             .find(|symbol| {
@@ -666,6 +666,13 @@ impl<const CAP: usize> UnityPointer<CAP> {
     }
 }
 
+#[derive(Copy, Clone, PartialEq, Hash, Debug)]
+enum BinaryFormat {
+    PE,
+    #[cfg(feature = "std")]
+    MachO,
+}
+
 struct Offsets {
     monoassembly_aname: u8,
     monoassembly_image: u8,
@@ -688,9 +695,9 @@ struct Offsets {
 }
 
 impl Offsets {
-    const fn new(version: Version, is_64_bit: bool) -> &'static Self {
-        match is_64_bit {
-            true => match version {
+    const fn new(version: Version, is_64_bit: bool, format: BinaryFormat) -> &'static Self {
+        match (is_64_bit, format) {
+            (true, BinaryFormat::PE) => match version {
                 Version::V1 => &Self {
                     monoassembly_aname: 0x10,
                     monoassembly_image: 0x58,
@@ -754,7 +761,7 @@ impl Offsets {
                     monoclassfieldalignment: 0x20,
                 },
             },
-            false => match version {
+            (false, BinaryFormat::PE) => match version {
                 Version::V1 => &Self {
                     monoassembly_aname: 0x8,
                     monoassembly_image: 0x40,
@@ -818,6 +825,54 @@ impl Offsets {
                     monoclassfieldalignment: 0x10,
                 },
             },
+            #[cfg(feature = "std")]
+            (true, BinaryFormat::MachO) => match version {
+                Version::V1 => &Self {
+                    monoassembly_aname: 0x10,
+                    monoassembly_image: 0x58, // matches 64-bit PE V1
+                    monoimage_class_cache: 0x3D0, // matches 64-bit PE V1
+                    monointernalhashtable_table: 0x20,
+                    monointernalhashtable_size: 0x18,
+                    monoclassdef_next_class_cache: 0xF8, // 0x8 less than 64-bit PE V1
+                    monoclassdef_klass: 0x0,
+                    monoclass_name: 0x40, // 0x8 less than 64-bit PE V1
+                    monoclass_fields: 0xA0, // 0x8 less than 64-bit PE V1
+                    monoclassdef_field_count: 0x8C, // 0x8 less than 64-bit PE V1
+                    monoclass_runtime_info: 0xF0, // 0x8 less than 64-bit PE V1
+                    monoclass_vtable_size: 0x18, // MonoVtable.data
+                    monoclass_parent: 0x28, // 0x8 less than 64-bit PE V1
+                    monoclassfield_name: 0x8,
+                    monoclassfield_offset: 0x18,
+                    monoclassruntimeinfo_domain_vtables: 0x8,
+                    monovtable_vtable: 0x0, // UNUSED for V1
+                    monoclassfieldalignment: 0x20,
+                },
+                // 64-bit MachO V2 matches Unity2019_4_2020_3_x64_MachO_Offsets from
+                // https://github.com/hackf5/unityspy/blob/master/src/HackF5.UnitySpy/Offsets/MonoLibraryOffsets.cs#L86
+                Version::V2 => &Self {
+                    monoassembly_aname: 0x10,
+                    monoassembly_image: 0x60, // AssemblyImage = 0x44 + 0x1c
+                    monoimage_class_cache: 0x4C0, // ImageClassCache = 0x354 + 0x16c
+                    monointernalhashtable_table: 0x20, // HashTableTable = 0x14 + 0xc
+                    monointernalhashtable_size: 0x18, // HashTableSize = 0xc + 0xc
+                    monoclassdef_next_class_cache: 0x100, // TypeDefinitionNextClassCache = 0xa8 + 0x34 + 0x10 + 0x18 + 0x4 - 0x8
+                    monoclassdef_klass: 0x0,
+                    monoclass_name: 0x40, // TypeDefinitionName = 0x2c + 0x1c - 0x8
+                    monoclass_fields: 0x90, // TypeDefinitionFields = 0x60 + 0x20 + 0x18 - 0x8
+                    monoclassdef_field_count: 0xF8, // TypeDefinitionFieldCount = 0xa4 + 0x34 + 0x10 + 0x18 - 0x8
+                    monoclass_runtime_info: 0xC8, // TypeDefinitionRuntimeInfo = 0x84 + 0x34 + 0x18 - 0x8
+                    monoclass_vtable_size: 0x54, // TypeDefinitionVTableSize = 0x38 + 0x24 - 0x8
+                    monoclass_parent: 0x28, // TypeDefinitionParent = 0x20 + 0x10 - 0x8
+                    monoclassfield_name: 0x8,
+                    monoclassfield_offset: 0x18,
+                    monoclassruntimeinfo_domain_vtables: 0x8, // TypeDefinitionRuntimeInfoDomainVTables = 0x4 + 0x4
+                    monovtable_vtable: 0x40, // VTable = 0x28 + 0x18
+                    monoclassfieldalignment: 0x20,
+                },
+                Version::V3 => panic!("MachO V3 not supported"),
+            },
+            #[cfg(feature = "std")]
+            (false, BinaryFormat::MachO) => panic!("32-bit MachO format not supported"),
         }
     }
 }