Forcefully disable item schema update on beta branches

Remove signature for filesystem, fetch it from factory instead

README.md

@@ -1,6 +1,9 @@
 # Custom Items Games plugin
 This client-side plugin bypasses integrity checks for items_games.txt and proto_defs.vpd in Team Fortress 2. The plugin will only work locally, and it is VAC-safe. Signature scanning is used which should make the plugin work consistently after updates.
 
+## Beta branches
+Beta branches `pre_07_25_23_demos` and `pre_smissmas_2022_demos` currently crash on boot due to the newer item schema. This plugin supports these branches and will also fix these crashes, by forcefully disabling item schema updating.
+
 ## Installation
 * Download the latest release and extract the "addons" folder to TF2's main folder (../common/Team Fortress 2/tf).
 * Go into tf/scripts/items, copy the items_game.txt and rename it to items_game_custom.txt. This file will be loaded instead of the original items_games.txt. proto_defs.vpd will still load the same file.

custom_items_games.vcxproj

@@ -21,6 +21,7 @@
   <ItemGroup>
     <ClInclude Include="address.h" />
     <ClInclude Include="detours.h" />
+    <ClInclude Include="filesystem.h" />
     <ClInclude Include="functions.h" />
     <ClInclude Include="helpers.h" />
     <ClInclude Include="module.h" />

filesystem.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdio.h>
+
+#define BASEFILESYSTEM_INTERFACE_VERSION "VBaseFileSystem011"
+
+typedef void* FileHandle_t;
+enum FileSystemSeek_t
+{
+	FILESYSTEM_SEEK_HEAD	= SEEK_SET,
+	FILESYSTEM_SEEK_CURRENT = SEEK_CUR,
+	FILESYSTEM_SEEK_TAIL	= SEEK_END,
+};
+
+class IBaseFileSystem
+{
+public:
+	virtual int				Read(void* pOutput, int size, FileHandle_t file) = 0;
+	virtual int				Write(void const* pInput, int size, FileHandle_t file) = 0;
+	virtual FileHandle_t	Open(const char* pFileName, const char* pOptions, const char* pathID = 0) = 0;
+	virtual void			Close(FileHandle_t file) = 0;
+	virtual void			Seek(FileHandle_t file, int pos, FileSystemSeek_t seekType) = 0;
+	virtual unsigned int	Tell(FileHandle_t file) = 0;
+	virtual unsigned int	Size(FileHandle_t file) = 0;
+	virtual unsigned int	Size(const char* pFileName, const char* pPathID = 0) = 0;
+	virtual void			Flush(FileHandle_t file) = 0;
+	virtual bool			Precache(const char* pFileName, const char* pPathID = 0) = 0;
+	virtual bool			FileExists(const char* pFileName, const char* pPathID = 0) = 0;
+};

functions.h

@@ -1,25 +1,7 @@
-#pragma optimize("", off)
-
 #define CUSTOM_ITEMS_GAME "scripts/items/items_game_custom.txt"
 #define CUSTOM_ITEMS_GAME_SIG CUSTOM_ITEMS_GAME ".sig"
 
-intptr_t server_fileSystem = 0;
-
-void gameStats_loadFromFile_resolve(AddressInfo<intptr_t>& addr, ModuleName mod)
-{
-	server_fileSystem = Deref(addr[mod] + 42);
-	Log(Color(0, 255, 200, 255), "Filesystem found at 0x%X in %s.%s\n", server_fileSystem, modules[mod].name, "dll");
-}
-
-typedef intptr_t gameStats_loadFromFile;
-ADDR_CALLBACK(
-	gameStats_loadFromFile,
-	"CBaseGameStats::LoadFromFile", 
-	MOD_SERVER,
-	\x55\x8B\xEC\x81\xEC\x38\x02\x00\x00\xA1\x2A\x2A\x2A\x2A,
-	xxxxxxxxxx????,
-	gameStats_loadFromFile_resolve
-);
+extern IBaseFileSystem* filesystem;
 
 typedef intptr_t (*econItemSystem)();
 ADDR(
@@ -32,22 +14,15 @@ ADDR(
 
 bool customItemsGameFound = false;
 
-typedef bool (__thiscall** filesystem_fileExists)(intptr_t, const char*, const char*);
-bool function_filesystem_fileExists(const char* filename)
-{
-	intptr_t filesystem = Deref(server_fileSystem) + 4;
-	return (*(filesystem_fileExists)(Deref(filesystem) + 40))(filesystem, filename, nullptr);
-}
-
 bool helper_check_custom_itemsgame()
 {
 	bool foundCustom = true;
-	if (!function_filesystem_fileExists(CUSTOM_ITEMS_GAME))
+	if (!filesystem->FileExists(CUSTOM_ITEMS_GAME))
 	{
 		Log(Color(255, 0, 127, 255), "Server: %s not found, loading default items_game.txt ...\n", CUSTOM_ITEMS_GAME);
 		foundCustom = false;
 	}
-	if (!function_filesystem_fileExists(CUSTOM_ITEMS_GAME_SIG))
+	if (!filesystem->FileExists(CUSTOM_ITEMS_GAME_SIG))
 	{
 		Log(Color(255, 0, 127, 255), "Server: %s not found, loading default items_game.txt ...\n", CUSTOM_ITEMS_GAME_SIG);
 		foundCustom = false;
@@ -96,6 +71,41 @@ void __fastcall hook_client_econItemSystem_parseItemSchemaFile(intptr_t thisptr,
 	address_econItemSystem_parseItemSchemaFile[MOD_CLIENT](thisptr, edx, filename);
 }
 
+bool is_demo_branch()
+{
+	FileHandle_t f = filesystem->Open("steam.inf", "r");
+	if (!f)
+	{
+		Log(Color(255, 0, 0, 255), "Failed to open steam.inf\n");
+		return false;
+	}
+
+	bool demo_branch = false;
+	bool patch_version = false;
+
+	char buffer[256];
+	filesystem->Read(buffer, sizeof(buffer), f);
+
+	char* p = strtok(buffer, "=\r\n");
+	while (p)
+	{
+		if (patch_version)
+		{
+			if (atoi(p) <= 8207200)
+				demo_branch = true;
+			break;
+		}
+
+		if (!strcmp(p, "PatchVersion"))
+			patch_version = true;
+
+		p = strtok(NULL, "=\r\n");
+	}
+
+	filesystem->Close(f);
+	return demo_branch;
+}
+
 typedef bool (__fastcall* gcUpdateItemSchema_runJob)(intptr_t, void*, void*);
 ADDR_GAME(
 	gcUpdateItemSchema_runJob,
@@ -109,6 +119,10 @@ void __fastcall hook_gcUpdateItemSchema_runJob(intptr_t thisptr, void* edx, void
 	{
 		Log(Color(0, 255, 127, 255), "Blocked item schema update from GC\n");
 	}
+	else if (is_demo_branch())
+	{
+		Log(Color(0, 255, 127, 255), "Forcefully blocked item schema update from GC (demo branch detected)\n");
+	}
 	else
 	{
 		address_gcUpdateItemSchema_runJob.Resolve(Deref(thisptr))(thisptr, edx, packet);

plugin.cpp

@@ -7,6 +7,7 @@
 #include "detours.h"
 
 #include "plugin.h"
+#include "filesystem.h"
 
 #include "helpers.h"
 #include "module.h"
@@ -46,6 +47,8 @@ public:
 
 CPlugin g_Plugin;
 
+IBaseFileSystem* filesystem = nullptr;
+
 extern "C" __declspec(dllexport) void* CreateInterface(const char* pName, int* pReturnCode)
 { 
 	if (!strcmp(INTERFACEVERSION_IPLUGIN, pName))
@@ -68,7 +71,17 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
 bool CPlugin::Load(CreateInterfaceFn interfaceFactory, CreateInterfaceFn gameServerFactory)
 {
 	if (!FindLog())
+	{
+		Log(Color(255, 0, 0, 255), "Failed to find logging func\n");
 		return false;
+	}
+
+	filesystem = (IBaseFileSystem*)interfaceFactory(BASEFILESYSTEM_INTERFACE_VERSION, NULL);
+	if (!filesystem)
+	{
+		Log(Color(255, 0, 0, 255), "Failed to find filesystem\n");
+		return false;
+	}
 
 	if (!FindModules())
 		return false;