SDK: Add FEnumProperty and offset bruteforcer

CMakeLists.txt

@@ -325,6 +325,7 @@ list(APPEND sdk_SOURCES
 	"shared/sdk/EngineModule.cpp"
 	"shared/sdk/FArrayProperty.cpp"
 	"shared/sdk/FBoolProperty.cpp"
+	"shared/sdk/FEnumProperty.cpp"
 	"shared/sdk/FField.cpp"
 	"shared/sdk/FMalloc.cpp"
 	"shared/sdk/FName.cpp"
@@ -366,6 +367,7 @@ list(APPEND sdk_SOURCES
 	"shared/sdk/EngineModule.hpp"
 	"shared/sdk/FArrayProperty.hpp"
 	"shared/sdk/FBoolProperty.hpp"
+	"shared/sdk/FEnumProperty.hpp"
 	"shared/sdk/FField.hpp"
 	"shared/sdk/FFieldClass.hpp"
 	"shared/sdk/FMalloc.hpp"

shared/sdk/FEnumProperty.cpp

@@ -0,0 +1,125 @@
+#include <spdlog/spdlog.h>
+#include <utility/String.hpp>
+
+#include "UObjectArray.hpp"
+#include "UClass.hpp"
+#include "UEnum.hpp"
+
+#include "FEnumProperty.hpp"
+
+namespace sdk {
+void FEnumProperty::update_offsets() {
+    if (s_updated_offsets) {
+        return;
+    }
+
+    s_updated_offsets = true;
+
+    SPDLOG_INFO("[FEnumProperty::update_offsets] Updating offsets");
+
+    const auto repmovement = sdk::find_uobject<sdk::UScriptStruct>(L"ScriptStruct /Script/Engine.RepMovement");
+
+    if (repmovement == nullptr) {
+        SPDLOG_ERROR("[FEnumProperty::update_offsets] Failed to find RepMovement");
+        return;
+    }
+
+    // Find the first EnumProperty
+    FEnumProperty* first_enum_property{nullptr};
+    FEnumProperty* second_enum_property{nullptr};
+
+    for (auto prop = repmovement->get_child_properties(); prop != nullptr; prop = prop->get_next()) {
+        const auto c = prop->get_class();
+
+        if (c == nullptr) {
+            continue;
+        }
+
+        if (c->get_name().to_string() == L"EnumProperty") {
+            if (first_enum_property == nullptr) {
+                first_enum_property = (FEnumProperty*)prop;
+            } else if (second_enum_property == nullptr) {
+                second_enum_property = (FEnumProperty*)prop;
+            } else {
+                break;
+            }
+        }
+    }
+
+    if (first_enum_property == nullptr) {
+        SPDLOG_ERROR("[FEnumProperty::update_offsets] Failed to find first enum property");
+        return;
+    }
+
+    if (second_enum_property == nullptr) {
+        SPDLOG_ERROR("[FEnumProperty::update_offsets] Failed to find second enum property");
+        return;
+    }
+
+    const auto first_enum_c = first_enum_property->get_class();
+    const auto second_enum_c = second_enum_property->get_class();
+
+    if (first_enum_c == nullptr || second_enum_c == nullptr) {
+        SPDLOG_ERROR("[FEnumProperty::update_offsets] Failed to find first or second enum class");
+        return;
+    }
+
+    // Start from FProperty's offset offset, and bruteforce until we find the correct offset
+    const auto initial_start = FProperty::s_offset_offset + 4 + sizeof(void*) + sizeof(void*);
+    // align up to sizeof(void*)
+    const auto start = (initial_start + sizeof(void*) - 1) & ~(sizeof(void*) - 1);
+
+    // underlying prop
+    for (auto i = start; i < start + 0x100; i += sizeof(void*)) try {
+        const auto potential_numeric_property_a = *(sdk::FProperty**)(first_enum_property + i);
+        const auto potential_numeric_property_b = *(sdk::FProperty**)(second_enum_property + i);
+
+        if (potential_numeric_property_a == nullptr || potential_numeric_property_b == nullptr) {
+            continue;
+        }
+
+        const auto potential_numeric_property_a_c = potential_numeric_property_a->get_class();
+        const auto potential_numeric_property_b_c = potential_numeric_property_b->get_class();
+
+        if (potential_numeric_property_a_c != nullptr && potential_numeric_property_b_c != nullptr) {
+            const auto potential_prop_a_c_name = potential_numeric_property_a_c->get_name().to_string();
+            const auto potential_prop_b_c_name = potential_numeric_property_b_c->get_name().to_string();
+
+            if (potential_prop_a_c_name == L"ByteProperty" && potential_prop_b_c_name == L"ByteProperty") {
+                s_underlying_prop_offset = i;
+                SPDLOG_INFO("[FEnumProperty::update_offsets] Found underlying prop offset: 0x{:X}", i);
+                break;
+            }
+        }
+    } catch(...) {
+        continue;
+    }
+
+    // UEnum
+    for (auto i = start; i < start + 0x100; i += sizeof(void*)) try {
+        const auto potential_enum_a = *(sdk::UEnum**)(first_enum_property + i);
+        const auto potential_enum_b = *(sdk::UEnum**)(second_enum_property + i);
+
+        if (potential_enum_a == nullptr || potential_enum_b == nullptr) {
+            continue;
+        }
+
+        const auto poential_enum_a_c = potential_enum_a->get_class();
+        const auto poential_enum_b_c = potential_enum_b->get_class();
+
+
+        if (poential_enum_a_c != nullptr && poential_enum_b_c != nullptr) {
+            const auto potential_enum_a_c_name = poential_enum_a_c->get_fname().to_string();
+            const auto potential_enum_b_c_name = poential_enum_b_c->get_fname().to_string();
+
+            if (potential_enum_a_c_name == L"Enum" && potential_enum_b_c_name == L"Enum") {
+                s_enum_offset = i;
+                SPDLOG_INFO("[FEnumProperty::update_offsets] Found enum offset: 0x{:X}", i);
+                break;
+            }
+        }
+    } catch(...) {
+        continue;
+    }
+}
+}

shared/sdk/FEnumProperty.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <cstdint>
+
+#include "FProperty.hpp"
+
+namespace sdk {
+struct FNumericProperty;
+struct FEnum;
+
+class FEnumProperty : public FProperty {
+public:
+    static void update_offsets();
+
+    FNumericProperty* get_underlying_prop() const {
+        return *(FNumericProperty**)((uintptr_t)this + s_underlying_prop_offset);
+    }
+
+    FEnum* get_enum() const {
+        return *(FEnum**)((uintptr_t)this + s_enum_offset);
+    }
+
+private:
+    static inline bool s_updated_offsets{false};
+    static inline uint32_t s_underlying_prop_offset{0x0}; // idk
+    static inline uint32_t s_enum_offset{0x0}; // idk
+};
+}

shared/sdk/UObjectArray.cpp

@@ -22,6 +22,7 @@
 #include "FBoolProperty.hpp"
 #include "FObjectProperty.hpp"
 #include "FArrayProperty.hpp"
+#include "FEnumProperty.hpp"
 #include "UObjectArray.hpp"
 
 namespace sdk {
@@ -416,6 +417,7 @@ FUObjectArray* FUObjectArray::get() try {
         sdk::FBoolProperty::update_offsets();
         sdk::FObjectProperty::update_offsets();
         sdk::FArrayProperty::update_offsets();
+        sdk::FEnumProperty::update_offsets();
 
 #ifdef TESTING_GUOBJECTARRAY
         try {