Add classes for finding RTTI on Windows

danielkrupinski · Dec 15, 2023 · a88ca48 · a88ca48
1 parent 7c35978
commit a88ca48
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Showing 8 changed files with 151 additions and 0 deletions.
diff --git a/Source/Osiris.vcxproj b/Source/Osiris.vcxproj
@@ -193,6 +193,11 @@
     <ClInclude Include="Platform\Windows\DLLs\Shell32Dll.h" />
     <ClInclude Include="Platform\Windows\PebLdr.h" />
     <ClInclude Include="Platform\Windows\PortableExecutable.h" />
+    <ClInclude Include="Platform\Windows\RTTI\RttiCompleteObjectLocator.h" />
+    <ClInclude Include="Platform\Windows\RTTI\RttiCompleteObjectLocatorFinder.h" />
+    <ClInclude Include="Platform\Windows\RTTI\RttiTypeDescriptor.h" />
+    <ClInclude Include="Platform\Windows\RTTI\RttiTypeDescriptorFinder.h" />
+    <ClInclude Include="Platform\Windows\RTTI\ToRvaConverter.h" />
     <ClInclude Include="Platform\Windows\UserDocumentsFolderPath.h" />
     <ClInclude Include="Platform\Windows\Win.h" />
     <ClInclude Include="Platform\Windows\WindowsDynamicLibrary.h" />

diff --git a/Source/Osiris.vcxproj.filters b/Source/Osiris.vcxproj.filters
@@ -97,6 +97,9 @@
     <Filter Include="FeatureHelpers\Hud">
       <UniqueIdentifier>{7a55ce58-0ac3-4a7f-817d-46121c678167}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Platform\Windows\RTTI">
+      <UniqueIdentifier>{3908a784-03e1-437a-97b7-7479673278cc}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="CS2\Classes\C_CSGameRules.h">
@@ -741,6 +744,21 @@
     <ClInclude Include="MemorySearch\BinaryBytePattern.h">
       <Filter>MemorySearch</Filter>
     </ClInclude>
+    <ClInclude Include="Platform\Windows\RTTI\RttiCompleteObjectLocatorFinder.h">
+      <Filter>Platform\Windows\RTTI</Filter>
+    </ClInclude>
+    <ClInclude Include="Platform\Windows\RTTI\RttiTypeDescriptor.h">
+      <Filter>Platform\Windows\RTTI</Filter>
+    </ClInclude>
+    <ClInclude Include="Platform\Windows\RTTI\RttiTypeDescriptorFinder.h">
+      <Filter>Platform\Windows\RTTI</Filter>
+    </ClInclude>
+    <ClInclude Include="Platform\Windows\RTTI\ToRvaConverter.h">
+      <Filter>Platform\Windows\RTTI</Filter>
+    </ClInclude>
+    <ClInclude Include="Platform\Windows\RTTI\RttiCompleteObjectLocator.h">
+      <Filter>Platform\Windows\RTTI</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="UI\Panorama\CreateGUI.js">

diff --git a/Source/Platform/Windows/RTTI/RttiCompleteObjectLocator.h b/Source/Platform/Windows/RTTI/RttiCompleteObjectLocator.h
@@ -0,0 +1,6 @@
+#pragma once
+
+struct RttiCompleteObjectLocator {
+    static constexpr auto kOffsetOfOffsetInCompleteClass{4};
+    static constexpr auto kOffsetOfTypeDescriptorRva{12};
+};
diff --git a/Source/Platform/Windows/RTTI/RttiCompleteObjectLocatorFinder.h b/Source/Platform/Windows/RTTI/RttiCompleteObjectLocatorFinder.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include <cstdint>
+#include <cstring>
+
+#include "RttiCompleteObjectLocator.h"
+#include "ToRvaConverter.h"
+#include <Utils/MemorySection.h>
+
+struct RttiTypeDescriptor;
+
+class RttiCompleteObjectLocatorFinder {
+public:
+    RttiCompleteObjectLocatorFinder(MemorySection rdataSection, ToRvaConverter toRvaConverter) noexcept
+        : rdataSection{rdataSection}
+        , toRvaConverter{toRvaConverter}
+    {
+    }
+
+    [[nodiscard]] const RttiCompleteObjectLocator* findCompleteObjectLocator(const RttiTypeDescriptor* typeDescriptor) const noexcept
+    {
+        const BinaryBytePattern typeDescriptorRvaPattern{toRvaConverter.toRva(reinterpret_cast<std::uintptr_t>(typeDescriptor))};
+        HybridPatternFinder typeDescriptorCrossReferenceFinder{rdataSection.raw(), typeDescriptorRvaPattern};
+
+        auto typeDescriptorReference{typeDescriptorCrossReferenceFinder.findNextOccurrence()};
+        while (typeDescriptorReference && (!isCompleteObjectLocator(reinterpret_cast<std::uintptr_t>(typeDescriptorReference)) || !isCompleteObjectLocatorOfCompleteClass(typeDescriptorReference)))
+            typeDescriptorReference = typeDescriptorCrossReferenceFinder.findNextOccurrence();
+
+        if (typeDescriptorReference)
+            return reinterpret_cast<const RttiCompleteObjectLocator*>(typeDescriptorReference - RttiCompleteObjectLocator::kOffsetOfTypeDescriptorRva);
+
+        return nullptr;
+    }
+
+private:
+    [[nodiscard]] bool isCompleteObjectLocatorOfCompleteClass(const std::byte* typeDescriptorReference) const noexcept
+    {
+        std::uint32_t offsetInCompleteClass;
+        std::memcpy(&offsetInCompleteClass, typeDescriptorReference - RttiCompleteObjectLocator::kOffsetOfTypeDescriptorRva + RttiCompleteObjectLocator::kOffsetOfOffsetInCompleteClass, sizeof(std::uint32_t));
+        return offsetInCompleteClass == 0;
+    }
+
+    [[nodiscard]] bool isCompleteObjectLocator(std::uintptr_t typeDescriptorReference) const noexcept
+    {
+        return hasNoCrossReferences(BinaryBytePattern{toRvaConverter.toRva(typeDescriptorReference)}) && rdataSection.offsetOf(typeDescriptorReference) >= RttiCompleteObjectLocator::kOffsetOfTypeDescriptorRva;
+    }
+
+    [[nodiscard]] bool hasNoCrossReferences(BytePattern pattern) const noexcept
+    {
+        return HybridPatternFinder{rdataSection.raw(), pattern}.findNextOccurrence() == nullptr;
+    }
+
+    MemorySection rdataSection;
+    ToRvaConverter toRvaConverter;
+};
diff --git a/Source/Platform/Windows/RTTI/RttiTypeDescriptor.h b/Source/Platform/Windows/RTTI/RttiTypeDescriptor.h
@@ -0,0 +1,5 @@
+#pragma once
+
+struct RttiTypeDescriptor {
+    static constexpr auto kOffsetOfName{16};
+};
diff --git a/Source/Platform/Windows/RTTI/RttiTypeDescriptorFinder.h b/Source/Platform/Windows/RTTI/RttiTypeDescriptorFinder.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string_view>
+
+#include <MemorySearch/HybridPatternFinder.h>
+#include "RttiTypeDescriptor.h"
+#include <Utils/MemorySection.h>
+
+class RttiTypeDescriptorFinder {
+public:
+    RttiTypeDescriptorFinder(MemorySection dataSection) noexcept
+        : dataSection{dataSection}
+    {
+    }
+
+    [[nodiscard]] const RttiTypeDescriptor* findTypeDescriptor(std::string_view mangledTypeName) const noexcept
+    {
+        if (const auto typeDescriptorName{findTypeDescriptorName(mangledTypeName)}; canBePartOfTypeDescriptor(typeDescriptorName))
+            return toTypeDescriptorPointer(typeDescriptorName);
+        return nullptr;
+    }
+
+private:
+    [[nodiscard]] const std::byte* findTypeDescriptorName(std::string_view typeDescriptorName) const noexcept
+    {
+        return HybridPatternFinder{dataSection.raw(), BytePattern{typeDescriptorName}}.findNextOccurrence();
+    }
+
+    [[nodiscard]] bool canBePartOfTypeDescriptor(const std::byte* typeDescriptorName) const noexcept
+    {
+        return typeDescriptorName && dataSection.offsetOf(reinterpret_cast<std::uintptr_t>(typeDescriptorName)) >= RttiTypeDescriptor::kOffsetOfName;
+    }
+
+    [[nodiscard]] static const RttiTypeDescriptor* toTypeDescriptorPointer(const std::byte* typeDescriptorName) noexcept
+    {
+        return reinterpret_cast<const RttiTypeDescriptor*>(typeDescriptorName - RttiTypeDescriptor::kOffsetOfName);
+    }
+
+    MemorySection dataSection;
+};
diff --git a/Source/Platform/Windows/RTTI/ToRvaConverter.h b/Source/Platform/Windows/RTTI/ToRvaConverter.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <cassert>
+#include <cstdint>
+
+struct ToRvaConverter {
+    [[nodiscard]] std::uint32_t toRva(std::uintptr_t address) const noexcept
+    {
+        assert(address >= baseAddress);
+        return static_cast<std::uint32_t>(address - baseAddress);
+    }
+
+    std::uintptr_t baseAddress;
+};
diff --git a/Source/Utils/MemorySection.h b/Source/Utils/MemorySection.h
@@ -28,6 +28,12 @@ struct MemorySection {
         return address >= base && address - base < size;
     }
 
+    [[nodiscard]] std::size_t offsetOf(std::uintptr_t address) const noexcept
+    {
+        assert(contains(address));
+        return address - base;
+    }
+
 private:
     std::uintptr_t base{0};
     std::size_t size{0};