Cvars: Hook Cvar_DirectSet from engine library

amxmodx/AMBuilder

@@ -96,6 +96,9 @@ binary.sources = [
   'stackstructs.cpp',
   'CTextParsers.cpp',
   'textparse.cpp',
+  'cvars.cpp',
+  '../public/memtools/CDetour/detours.cpp',
+  '../public/memtools/CDetour/asm/asm.c',
 ]
 
 if builder.target_platform == 'windows':

amxmodx/cvars.cpp

@@ -0,0 +1,70 @@
+// vim: set ts=4 sw=4 tw=99 noet:
+//
+// AMX Mod X, based on AMX Mod by Aleksander Naszko ("OLO").
+// Copyright (C) The AMX Mod X Development Team.
+//
+// This software is licensed under the GNU General Public License, version 3 or higher.
+// Additional exceptions apply. For full license details, see LICENSE.txt or visit:
+//     https://alliedmods.net/amxmodx-license
+
+#include "cvars.h"
+#include "amxmodx.h"
+#include <CDetour/detours.h>
+
+CDetour *Cvar_DirectSetDetour;
+
+DETOUR_DECL_STATIC2(Cvar_DirectSet, void, struct cvar_s*, var, const char*, value)
+{
+	printf("Cvar_DirectSet - %s -> %s\n", var->name, value);
+
+	DETOUR_STATIC_CALL(Cvar_DirectSet)(var, value);
+}
+
+void CreateCvarHook(void)
+{
+	// void PF_Cvar_DirectSet(struct cvar_s *var, const char *value) // = pfnCvar_DirectSet
+	// {
+	//   	Cvar_DirectSet(var, value); // <- We want to hook this.
+	// }
+
+	byte *baseAddress = (byte *)g_engfuncs.pfnCvar_DirectSet;
+	uintptr_t *functionAddress = nullptr;
+
+#if defined(WIN32)
+	// 55              push    ebp
+	// 8B EC           mov     ebp, esp
+	// 8B 45 0C        mov     eax, [ebp+arg_4]
+	// 8B 4D 08        mov     ecx, [ebp+arg_0]
+	// 50              push    eax
+	// 51              push    ecx
+	// E8 XX XX XX XX  call    Cvar_DirectSet
+	const byte opcodeJump = 0xE8;
+#else
+	// E9 XX XX XX XX  jmp     Cvar_DirectSet
+	const byte opcodeJump = 0xE9;
+#endif
+
+	const byte opcodeJumpSize     = 5;
+	const byte opcodeJumpByteSize = 1;
+
+	const int maxBytesLimit = 20;
+
+	for (size_t i = 0; i < maxBytesLimit; ++i, ++baseAddress)
+	{
+		if (*baseAddress == opcodeJump)
+		{
+			functionAddress = (uintptr_t *)(&baseAddress[opcodeJumpSize] + *(uintptr_t *)&baseAddress[opcodeJumpByteSize]);
+			break;
+		}
+	}
+
+	if (functionAddress)
+	{
+		CDetour *Cvar_DirectSetDetour = DETOUR_CREATE_STATIC_FIXED(Cvar_DirectSet, (void *)functionAddress);
+
+		if (Cvar_DirectSetDetour)
+		{
+			Cvar_DirectSetDetour->EnableDetour();
+		}
+	}
+}

amxmodx/cvars.h

@@ -0,0 +1,19 @@
+// vim: set ts=4 sw=4 tw=99 noet:
+//
+// AMX Mod X, based on AMX Mod by Aleksander Naszko ("OLO").
+// Copyright (C) The AMX Mod X Development Team.
+//
+// This software is licensed under the GNU General Public License, version 3 or higher.
+// Additional exceptions apply. For full license details, see LICENSE.txt or visit:
+//     https://alliedmods.net/amxmodx-license
+
+#ifndef CVARS_H
+#define CVARS_H
+
+class CDetour;
+
+void CreateCvarHook(void);
+
+extern CDetour *Cvar_DirectSetDetour;
+
+#endif // CVARS_H

amxmodx/meta_api.cpp

@@ -31,6 +31,7 @@
 #include "trie_natives.h"
 #include "CDataPack.h"
 #include "textparse.h"
+#include "cvars.h"
 
 plugin_info_t Plugin_info = 
 {
@@ -1488,6 +1489,8 @@ C_DLLEXPORT	int	Meta_Attach(PLUG_LOADTIME now, META_FUNCTIONS *pFunctionTable, m
 	GET_HOOK_TABLES(PLID, &g_pEngTable, NULL, NULL);
 
 	FlagMan.SetFile("cmdaccess.ini");
+
+	CreateCvarHook();
 	
 	return (TRUE);
 }

amxmodx/msvc12/amxmodx_mm.vcxproj

@@ -96,7 +96,7 @@
     </Midl>
     <ClCompile>
       <Optimization>Disabled</Optimization>
-      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\memtools;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;amxmodx_EXPORTS;PAWN_CELL_SIZE=32;ASM32;JIT;_CRT_SECURE_NO_DEPRECATE;HAVE_STDINT_H;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
@@ -149,7 +149,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <FavorSizeOrSpeed>Speed</FavorSizeOrSpeed>
       <OmitFramePointers>true</OmitFramePointers>
-      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\memtools;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;_USRDLL;amxmodx_EXPORTS;JIT;ASM32;PAWN_CELL_SIZE=32;_CRT_SECURE_NO_DEPRECATE;HAVE_STDINT_H;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <IgnoreStandardIncludePath>false</IgnoreStandardIncludePath>
       <StringPooling>true</StringPooling>
@@ -200,7 +200,7 @@
     </Midl>
     <ClCompile>
       <Optimization>Disabled</Optimization>
-      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\memtools;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;_USRDLL;amxmodx_EXPORTS;PAWN_CELL_SIZE=32;ASM32;JIT;BINLOG_ENABLED;_CRT_SECURE_NO_DEPRECATE;HAVE_STDINT_H;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
@@ -252,7 +252,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <FavorSizeOrSpeed>Speed</FavorSizeOrSpeed>
       <OmitFramePointers>true</OmitFramePointers>
-      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>..\;..\..\public;..\..\public\memtools;..\..\public\sdk;..\..\public\amtl;$(METAMOD)\metamod;$(HLSDK)\common;$(HLSDK)\engine;$(HLSDK)\dlls;$(HLSDK)\pm_shared;$(HLSDK)\public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;HAVE_STDINT_H;_USRDLL;amxmodx_EXPORTS;JIT;ASM32;PAWN_CELL_SIZE=32;BINLOG_ENABLED;_CRT_SECURE_NO_DEPRECATE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <IgnoreStandardIncludePath>false</IgnoreStandardIncludePath>
       <StringPooling>true</StringPooling>
@@ -292,6 +292,8 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="..\..\public\memtools\CDetour\asm\asm.c" />
+    <ClCompile Include="..\..\public\memtools\CDetour\detours.cpp" />
     <ClCompile Include="..\amx.cpp" />
     <ClCompile Include="..\amxcore.cpp" />
     <ClCompile Include="..\amxdbg.cpp" />
@@ -317,6 +319,7 @@
     <ClCompile Include="..\CPlugin.cpp" />
     <ClCompile Include="..\CTask.cpp" />
     <ClCompile Include="..\CTextParsers.cpp" />
+    <ClCompile Include="..\cvars.cpp" />
     <ClCompile Include="..\CVault.cpp" />
     <ClCompile Include="..\datapacks.cpp" />
     <ClCompile Include="..\debugger.cpp" />
@@ -360,6 +363,9 @@
     </ClCompile>
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="..\..\public\memtools\CDetour\asm\asm.h" />
+    <ClInclude Include="..\..\public\memtools\CDetour\detourhelpers.h" />
+    <ClInclude Include="..\..\public\memtools\CDetour\detours.h" />
     <ClInclude Include="..\amx.h" />
     <ClInclude Include="..\amxdbg.h" />
     <ClInclude Include="..\amxmodx.h" />
@@ -383,6 +389,7 @@
     <ClInclude Include="..\CString.h" />
     <ClInclude Include="..\CTask.h" />
     <ClInclude Include="..\CTextParsers.h" />
+    <ClInclude Include="..\cvars.h" />
     <ClInclude Include="..\CVault.h" />
     <ClInclude Include="..\CVector.h" />
     <ClInclude Include="..\datastructs.h" />

amxmodx/msvc12/amxmodx_mm.vcxproj.filters

@@ -25,6 +25,15 @@
     <Filter Include="Pawn Includes">
       <UniqueIdentifier>{4022451d-eb5f-4f14-b8d8-2ce23fec6e59}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Memtools">
+      <UniqueIdentifier>{a1f7babf-acb1-4a06-92e9-e8a411e1f02a}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="Memtools\CDetour">
+      <UniqueIdentifier>{8b35d490-2b01-4997-ba02-5e2cfd9c9017}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="Memtools\CDetour\asm">
+      <UniqueIdentifier>{64a22cd4-3715-45de-8af2-e54017733be6}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\amx.cpp">
@@ -183,6 +192,15 @@
     <ClCompile Include="..\..\public\sdk\amxxmodule.cpp">
       <Filter>SDK</Filter>
     </ClCompile>
+    <ClCompile Include="..\cvars.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\public\memtools\CDetour\detours.cpp">
+      <Filter>Memtools\CDetour</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\public\memtools\CDetour\asm\asm.c">
+      <Filter>Memtools\CDetour\asm</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\amx.h">
@@ -329,6 +347,18 @@
     <ClInclude Include="..\..\public\sdk\moduleconfig.h">
       <Filter>SDK</Filter>
     </ClInclude>
+    <ClInclude Include="..\cvars.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\public\memtools\CDetour\detourhelpers.h">
+      <Filter>Memtools\CDetour</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\public\memtools\CDetour\detours.h">
+      <Filter>Memtools\CDetour</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\public\memtools\CDetour\asm\asm.h">
+      <Filter>Memtools\CDetour\asm</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\version.rc">

public/memtools/CDetour/detours.h

@@ -32,10 +32,12 @@
 #ifndef _INCLUDE_SOURCEMOD_DETOURS_H_
 #define _INCLUDE_SOURCEMOD_DETOURS_H_
 
-#include "amxxmodule.h"
 //#include <jit/jit_helpers.h>
 //#include <jit/x86/x86_macros.h>
 #include "detourhelpers.h"
+#include <stdint.h>
+
+typedef int32_t cell;
 
 /**
  * CDetours class for SourceMod Extensions by pRED*