[IO]: Add functions to read file streams safely (#862)

src/Components/Modules/GSC/IO.cpp

@@ -6,15 +6,86 @@ namespace Components::GSC
 {
 	const char* IO::ForbiddenStrings[] = { R"(..)", R"(../)", R"(..\)" };
 
+	FILE* IO::openScriptIOFileHandle;
+
 	std::filesystem::path IO::Path;
 
+	void IO::GScr_OpenFile()
+	{
+		const auto* filepath = Game::Scr_GetString(0);
+		const auto* mode = Game::Scr_GetString(1);
+
+		if (mode != "read"s)
+		{
+			Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "Valid openfile modes are 'read'\n");
+			Game::Scr_AddInt(-1);
+			return;
+		}
+
+		if (openScriptIOFileHandle)
+		{
+			Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "OpenFile failed. {} files already open\n", 1);
+			Game::Scr_AddInt(-1);
+			return;
+		}
+
+		const auto scriptData = Path / "scriptdata"s / filepath;
+
+		_set_errno(0);
+		const auto result = fopen_s(&openScriptIOFileHandle, scriptData.string().data(), "r");
+		if (result || !openScriptIOFileHandle)
+		{
+			Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "OpenFile failed. '{}'", result);
+			Game::Scr_AddInt(-1);
+			return;
+		}
+
+		Game::Scr_AddInt(1);
+	}
+
+	void IO::GScr_ReadStream()
+	{
+		if (!openScriptIOFileHandle)
+		{
+			Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "ReadStream failed. File stream was not opened\n");
+			return;
+		}
+
+		char line[1024]{};
+		if (std::fgets(line, sizeof(line), openScriptIOFileHandle) != nullptr)
+		{
+			Game::Scr_AddString(line);
+			return;
+		}
+
+		Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "ReadStream failed.\n");
+		
+		if (std::feof(openScriptIOFileHandle))
+		{
+			Logger::Print(Game::CON_CHANNEL_PARSERSCRIPT, "ReadStream: EOF reached\n");
+		}
+	}
+
+	void IO::GScr_CloseFile()
+	{
+		if (!openScriptIOFileHandle)
+		{
+			Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "CloseFile failed. File stream was not opened\n");
+			Game::Scr_AddInt(-1);
+			return;
+		}
+
+		Game::Scr_AddInt(std::fclose(openScriptIOFileHandle));
+		openScriptIOFileHandle = nullptr;
+	}
+
 	void IO::AddScriptFunctions()
 	{
 		Script::AddFunction("FileWrite", [] // gsc: FileWrite(<filepath>, <string>, <mode>)
 		{
 			const auto* filepath = Game::Scr_GetString(0);
-			auto* text = Game::Scr_GetString(1);
+			const auto* text = Game::Scr_GetString(1);
-			auto* mode = Game::Scr_GetString(2);
+			const auto* mode = Game::Scr_GetString(2);
 
 			if (!filepath)
 			{
@@ -32,14 +103,14 @@ namespace Components::GSC
 			{
 				if (std::strstr(filepath, ForbiddenStrings[i]) != nullptr)
 				{
-					Logger::PrintError(Game::CON_CHANNEL_ERROR, "FileWrite: directory traversal is not allowed!\n");
+					Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "FileWrite: directory traversal is not allowed!\n");
 					return;
 				}
 			}
 
 			if (mode != "append"s && mode != "write"s)
 			{
-				Logger::Warning(Game::CON_CHANNEL_SCRIPT, "FileWrite: mode not defined or was wrong, defaulting to 'write'\n");
+				Logger::Warning(Game::CON_CHANNEL_PARSERSCRIPT, "FileWrite: mode not defined or was wrong, defaulting to 'write'\n");
 				mode = "write";
 			}
 
@@ -61,7 +132,7 @@ namespace Components::GSC
 			{
 				if (std::strstr(filepath, ForbiddenStrings[i]) != nullptr)
 				{
-					Logger::PrintError(Game::CON_CHANNEL_ERROR, "FileRead: directory traversal is not allowed!\n");
+					Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "FileRead: directory traversal is not allowed!\n");
 					return;
 				}
 			}
@@ -71,7 +142,7 @@ namespace Components::GSC
 			std::string file;
 			if (!Utils::IO::ReadFile(scriptData.string(), &file))
 			{
-				Logger::PrintError(Game::CON_CHANNEL_ERROR, "FileRead: file '{}' not found!\n", scriptData.string());
+				Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "FileRead: file '{}' not found!\n", scriptData.string());
 				return;
 			}
 
@@ -92,7 +163,7 @@ namespace Components::GSC
 			{
 				if (std::strstr(filepath, ForbiddenStrings[i]) != nullptr)
 				{
-					Logger::PrintError(Game::CON_CHANNEL_ERROR, "FileExists: directory traversal is not allowed!\n");
+					Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "FileExists: directory traversal is not allowed!\n");
 					return;
 				}
 			}
@@ -114,7 +185,7 @@ namespace Components::GSC
 			{
 				if (std::strstr(filepath, ForbiddenStrings[i]) != nullptr)
 				{
-					Logger::Print("FileRemove: directory traversal is not allowed!\n");
+					Logger::PrintError(Game::CON_CHANNEL_PARSERSCRIPT, "FileRemove: directory traversal is not allowed!\n");
 					return;
 				}
 			}
@@ -122,12 +193,21 @@ namespace Components::GSC
 			const auto scriptData = Path / "scriptdata"s / filepath;
 			Game::Scr_AddInt(Utils::IO::RemoveFile(scriptData.string()));
 		});
+
+		Script::AddFunction("ReadStream", GScr_ReadStream);
 	}
 
 	IO::IO()
 	{
+		openScriptIOFileHandle = nullptr;
 		Path = "userraw"s;
 
 		AddScriptFunctions();
+
+		Utils::Hook::Set<Game::BuiltinFunction>(0x79A858, GScr_OpenFile);
+		Utils::Hook::Set<int>(0x79A85C, 0);
+
+		Utils::Hook::Set<Game::BuiltinFunction>(0x79A864, GScr_CloseFile);
+		Utils::Hook::Set<int>(0x79A868, 0);
 	}
 }

src/Components/Modules/GSC/IO.hpp

@@ -10,8 +10,14 @@ namespace Components::GSC
 	private:
 		static const char* ForbiddenStrings[];
 
+		static FILE* openScriptIOFileHandle;
+
 		static std::filesystem::path Path;
 
+		static void GScr_OpenFile();
+		static void GScr_ReadStream();
+		static void GScr_CloseFile();
+
 		static void AddScriptFunctions();
 	};
 }