base for proxy objects

Author: 1fbff5f83b23d39d38b1dfcb4cac8d9b

byond-extools/src/core/core.cpp

@@ -1,6 +1,7 @@
 #include "core.h"
 #include "find_functions.h"
 #include "../tffi/tffi.h"
+#include "../proxy/proxy_object.h"
 
 CrashProcPtr CrashProc;
 SuspendPtr Suspend;
@@ -17,10 +18,16 @@ ProcSetupEntry** Core::proc_setup_table;
 std::map<unsigned int, opcode_handler> Core::opcode_handlers;
 std::map<std::string, unsigned int> Core::name_to_opcode;
 unsigned int next_opcode_id = 0x1337;
+bool Core::initialized = false;
 
 bool Core::initialize()
 {
-	return find_functions() && populate_proc_list();
+	if (initialized)
+	{
+		return true;
+	}
+	initialized = find_functions() && populate_proc_list() && hook_custom_opcodes();
+	return initialized;
 }
 
 void Core::Alert(const char* what) {
@@ -49,17 +56,19 @@ extern "C" EXPORT const char* core_initialize(int n_args, const char* args)
 		Core::Alert("Core init failed!");
 		return bad;
 	}
-	if (!Core::hook_em())
-	{
-		Core::Alert("Hooking failed!");
-		return bad;
-	}
 	return good;
 }
 
 extern "C" EXPORT const char* tffi_initialize(int n_args, const char* args)
 {
-	if (!TFFI::initialize())
+	if (!(Core::initialize() && TFFI::initialize()))
+		return bad;
+	return good;
+}
+
+extern "C" EXPORT const char* proxy_initialize(int n_args, const char* args)
+{
+	if (!(Core::initialize() && Proxy::initialize()))
 		return bad;
 	return good;
 }

byond-extools/src/core/core.h

@@ -25,4 +25,5 @@ namespace Core
 	unsigned int register_opcode(std::string name, opcode_handler handler);
 	void Alert(const char* what);
 	bool initialize();
+	extern bool initialized;
 }

byond-extools/src/core/hooking.cpp

@@ -1,8 +1,7 @@
 #include "hooking.h"
 
 #ifdef _WIN32
-PLH::CapstoneDisassembler* disassembler;
-PLH::x86Detour* CrashProcDetour;
+static PLH::CapstoneDisassembler* disassembler;
 #else
 urmem::hook CrashProcDetour;
 #endif
@@ -22,37 +21,47 @@ void hCrashProc(char* error, int argument)
 #endif
 }
 
-bool Core::hook_em()
+
+void* Core::install_hook(void* original, void* hook)
 {
 #ifdef _WIN32
 	disassembler = new PLH::CapstoneDisassembler(PLH::Mode::x86);
 	if (!disassembler)
 	{
-		return false;
+		return nullptr;
 	}
-	std::uint64_t sendMapsTrampoline;
-	CrashProcDetour = new PLH::x86Detour((char*)CrashProc, (char*)&hCrashProc, &sendMapsTrampoline, *disassembler);
-	if (!CrashProcDetour)
+	std::uint64_t trampoline;
+	PLH::x86Detour* detour = new PLH::x86Detour((char*)original, (char*)hook, &trampoline, *disassembler);
+	if (!detour)
 	{
-		return false;
+		Core::Alert("No detour");
+		return nullptr;
 	}
-	if (!CrashProcDetour->hook())
+	if (!detour->hook())
 	{
-		return false;
+		Core::Alert("hook failed");
+		return nullptr;
 	}
-	oCrashProc = PLH::FnCast(sendMapsTrampoline, oCrashProc);
-	if (!oCrashProc)
+	return (void*)trampoline;
+#else
+	detour.install(original, hook);
+	detour.enable();
+	if (!detour.is_enabled())
 	{
-		CrashProcDetour->unHook();
-		return false;
+		detour.disable();
+		return nullptr;
 	}
+	return (void*)detour;
+#endif
+}
+
+bool Core::hook_custom_opcodes()
+{
+#ifdef _WIN32
+	oCrashProc = (CrashProcPtr)install_hook(CrashProc, hCrashProc);
+	return oCrashProc;
 #else
-	CrashProcDetour.install(urmem::get_func_addr(CrashProc), urmem::get_func_addr(hCrashProc));
-	CrashProcDetour.enable();
-	if(!CrashProcDetour.is_enabled()) {
-		CrashProcDetour.disable();
-		return false;
-	}
+	CrashProcDetour = (CrashProcDetour)install_hook(CrashProc, hCrashProc);
+	return CrashProcDetour;
 #endif
-	return true;
 }

byond-extools/src/core/hooking.h

@@ -11,5 +11,6 @@
 
 namespace Core
 {
-	bool hook_em();
+	void* install_hook(void* original, void* hook);
+	bool hook_custom_opcodes();
 }

byond-extools/src/proxy/proxy_object.cpp

@@ -0,0 +1,14 @@
+#include "proxy_object.h"
+
+GetVariablePtr oGetVariable;
+
+Value hGetVariable(Value datum, unsigned int name_id)
+{
+	return oGetVariable(datum, name_id);
+}
+
+bool Proxy::initialize()
+{
+	oGetVariable = (GetVariablePtr)Core::install_hook(GetVariable, hGetVariable);
+	return true;
+}

byond-extools/src/proxy/proxy_object.h

@@ -0,0 +1,6 @@
+#include "../core/core.h"
+
+namespace Proxy
+{
+	bool initialize();
+}

byond-extools/src/tffi/tffi.cpp

@@ -26,10 +26,10 @@ void tffi_suspend(ExecutionContext* ctx)
 
 bool TFFI::initialize()
 {
+	// the CrashProc hook is currently super broken on Linux. It hooks but doesn't stop the crash.
+#ifdef _WIN32
 	int suspension_opcode = Core::register_opcode("TFFI_SUSPEND", tffi_suspend);
 	Core::Proc internal_resolve = Core::get_proc("/datum/promise/proc/__internal_resolve");
-#ifdef _WIN32
-	// the CrashProc hook is currently super broken on Linux. It hooks but doesn't stop the crash.
 	internal_resolve.set_bytecode(new std::vector<int>({ suspension_opcode, 0, 0, 0 }));
 #endif
 	result_string_id = GetStringTableIndex("result", 0, 1);