iw4x-client/src/Components/Modules/PlayerName.cpp

#include <STDInclude.hpp>
#include "ClanTags.hpp"
#include "PlayerName.hpp"
#include "TextRenderer.hpp"

namespace Components
{
	Dvar::Var PlayerName::sv_allowColoredNames;

	void PlayerName::UserInfoCopy(char* buffer, const char* name, const int size)
	{
		if (!sv_allowColoredNames.get<bool>())
		{
			char nameBuffer[64]{};
			TextRenderer::StripColors(name, nameBuffer, sizeof(nameBuffer));
			TextRenderer::StripAllTextIcons(nameBuffer, buffer, size);
		}
		else
		{
			TextRenderer::StripAllTextIcons(name, buffer, size);
		}

		std::string readablePlayerName(buffer);
		Utils::String::Trim(readablePlayerName);

		if (readablePlayerName.size() < 3)
		{
			strncpy(buffer, "Unknown Soldier", size);
		}
	}

	__declspec(naked) void PlayerName::ClientCleanName()
	{
		__asm
		{
			pushad

			push [esp + 0x20 + 0x4] // length
			push ecx // name
			push edx // buffer

			call UserInfoCopy
			add esp, 0xC

			popad

			ret
		}
	}

	int PlayerName::GetClientName(int localClientNum, int index, char* buf, int size)
	{
		const auto result = Game::CL_GetClientName(localClientNum, index, buf, size);

		// Prepend clanName to username & remove the colors
		strncpy_s(buf, size, TextRenderer::StripColors(ClanTags::GetClanTagWithName(index, buf)).data(), size);

		return result;
	}

	char* PlayerName::CleanStrStub(char* string)
	{
		TextRenderer::StripColors(string, string, std::strlen(string) + 1);
		return string;
	}

	bool PlayerName::IsBadChar(int c)
	{
		if (c == '%')
		{
			return true;
		}

		if (c == '~')
		{
			return true;
		}

		if (c < 32 || c > 126)
		{
			return true;
		}

		return false;
	}

	bool PlayerName::CopyClientNameCheck(char* dest, const char* source, int size)
	{
		Utils::Hook::Call<void(char*, const char*, int)>(0x4D6F80)(dest, source, size); // I_strncpyz

		auto i = 0;
		while (i < size - 1 && dest[i] != '\0')
		{
			// Check for various illegal characters
			const auto c = static_cast<unsigned char>(dest[i]);
			if (IsBadChar(c))
			{
				return false;
			}

			++i;
		}

		return true;
	}

	void PlayerName::DropClient(Game::client_s* drop)
	{
		const auto* reason = "Invalid name detected";
		Network::SendCommand(drop->header.netchan.remoteAddress, "error", reason);
		Game::SV_DropClient(drop, reason, false);
	}

	__declspec(naked) void PlayerName::SV_UserinfoChangedStub()
	{
		__asm
		{
			call CopyClientNameCheck
			test al, al

			jnz returnSafe

			pushad

			push edi // drop
			call DropClient
			add esp, 0x4

			popad

		returnSafe:
			push 0x401988
			retn
		}
	}

	PlayerName::PlayerName()
	{
		sv_allowColoredNames = Dvar::Register<bool>("sv_allowColoredNames", true, Game::DVAR_NONE, "Allow colored names on the server");

		// Disable SV_UpdateUserinfo_f to block changing the name ingame
		Utils::Hook::Set<BYTE>(0x6258D0, 0xC3);

		// Allow colored names ingame. Hook placed in ClientUserinfoChanged
		Utils::Hook(0x445301, ClientCleanName, HOOK_CALL).install()->quick();
		Utils::Hook(0x44533A, ClientCleanName, HOOK_CALL).install()->quick();

		// Though, don't apply that to overhead names.
		Utils::Hook(0x581932, GetClientName, HOOK_CALL).install()->quick();

		// Patch I_CleanStr
		Utils::Hook(0x4AD470, CleanStrStub, HOOK_JUMP).install()->quick();

		// Detect invalid characters including '%' to prevent format string vulnerabilities.
		// Kicks the player as soon as possible
		Utils::Hook(0x401983, SV_UserinfoChangedStub, HOOK_JUMP).install()->quick();
	}
}