registering own commands

[zdohdds]

Hello. I'm trying to write registration and use own commands, but how to do it i don't know.

Example for use from the game:

.help <----- default command

.settodo [x] <------ my command

On the forum I found interesting functions like:

// 3.3.5a 12340
00769100    ConsoleCommandRegister
007689E0    ConsoleCommandUnregister

but my attempts somehow to use them nor to no avail.

C++

//00769100    ConsoleCommandRegister
//int __cdecl sub_769100(char *a1, int a2, int a3, int a4)
int ConsoleCommandRegister(char *a1, int a2, int a3, int a4)
{
	return ((int(__cdecl*)(char*, int, int, int))0x769100)(a1, a2, a3, a4);
}

void Kek()
{
	MessageBox("i'm here");
}

//...
ConsoleCommandRegister("kek", (DWORD)Kek, 4, 0);
//...

PS: sorry for my bad English.

[namreeb]

The function you found is to register Lua functions. The commands you're mentioning are commands processed by the server, not the client.

If you want to process .commands you certainly can. You merely need to intercept the function which sends chat messages to the server, and if it is a command, process it, and prevent the message from being sent to the server. Careful with how you do this though. Be sure that the message isn't encrypted or you will defund your crypto session with the server.

[zdohdds]

You merely need to intercept the function which sends chat messages to the server...

Thank you for the idea.

I started search with lua_SendChatMessage and found this function:

// 3.3.5a 12340
int __usercall lua_SendChatMessage@<eax>(int edi0@<edi>, int a1)
{
	//...
	sub_577D00(*(int *)v37, &v31, 0x100u);
	//...
}

where 0x100u it's length the input text

I tried to hook it like:

//int __cdecl sub_577D00(int a1, _BYTE *a2, unsigned int a3)
typedef int(__cdecl* WoWSendMessageDelegate)(char*, int, int);
WoWSendMessageDelegate WoWSendMessage = (WoWSendMessageDelegate)0x577D00;
BYTE WSM_original_bytes[5] = { 0, 0, 0, 0, 0 };
BYTE WSM_hook_bytes[5] = { 0, 0, 0, 0, 0 };
DWORD WSM_original_protection = 0;

int __cdecl WoWSendMessageHook(char* pText, int unk_1, int textSize)
{
	memcpy(WoWSendMessage, WSM_original_bytes, 5);
	MyMessageBox(pText);
	int ret = 0;
	if (pText[0] == '.') // <----- some command for the test. Example: ".test"
	{
		ret = WoWSendMessage(pText, unk_1, 0);
	}
	else ret = WoWSendMessage(pText, unk_1, textSize);
	memcpy(WoWSendMessage, WSM_hook_bytes, 5);

	return ret;
}

void WoWSendMessageInitHook()
{
	memcpy(WSM_original_bytes, WoWSendMessage, 5);
	WSM_hook_bytes[0] = 0xE9;
	DWORD addr = (DWORD)WoWSendMessageHook - (DWORD)WoWSendMessage - 5;
	memcpy(WSM_hook_bytes + 1, &addr, 5);
	VirtualProtect(WoWSendMessage, 8, PAGE_EXECUTE_READWRITE, &WSM_original_protection);
	memcpy(WoWSendMessage, WSM_hook_bytes, 5);
}

And it's work. If it's my command, not sent to the server.