config.go: Add a new bool for reader limits

config.go

@@ -24,6 +24,10 @@ type Config struct {
 			// to the proxy and start communicating.
 			Secret string `json:"secret"`
 		} `json:"communication"`
+		// ReaderLimits determines if things like slices will have a maximum length as they are read from socket clients.
+		// It is recommended that this is always set to true in order to prevent possible attack vectors, however if any
+		// non-malicious clients are reaching these limits, you may want to disable it.
+		ReaderLimits bool `json:"reader_limits"`
 	} `json:"network"`
 	// Logger holds settings related to the logging aspects of the proxy.
 	Logger struct {
@@ -62,6 +66,7 @@ type Config struct {
 func DefaultConfig() (c Config) {
 	c.Network.Address = ":19132"
 	c.Network.Communication.Address = ":19131"
+	c.Network.ReaderLimits = true
 	c.Logger.File = "proxy.log"
 	c.Logger.Level = "debug"
 	c.PlayerLatency.Report = true

examples/main.go

@@ -65,7 +65,7 @@ func main() {
 		logger.Fatalf("failed to listen on %s: %v", conf.Network.Address, err)
 	}
 
-	socketServer := socket.NewDefaultServer(conf.Network.Communication.Address, conf.Network.Communication.Secret, p.SessionStore(), p.ServerRegistry(), logger)
+	socketServer := socket.NewDefaultServer(conf.Network.Communication.Address, conf.Network.Communication.Secret, p.SessionStore(), p.ServerRegistry(), logger, conf.Network.ReaderLimits)
 	if err := socketServer.Listen(); err != nil {
 		p.Logger().Fatalf("socket server failed to listen: %v", err)
 	}

socket/client.go

@@ -17,6 +17,8 @@ type Client struct {
 	log  internal.Logger
 	conn net.Conn
 
+	readerLimits bool
+
 	pool packet.Pool
 
 	sendMu sync.Mutex
@@ -29,11 +31,13 @@ type Client struct {
 
 // NewClient creates a new socket Client with default allocations and required data. It pre-allocates 4096
 // bytes to prevent allocations during runtime as much as possible.
-func NewClient(conn net.Conn, log internal.Logger) *Client {
+func NewClient(conn net.Conn, log internal.Logger, readerLimits bool) *Client {
 	return &Client{
 		log:  log,
 		conn: conn,
 
+		readerLimits: readerLimits,
+
 		pool: packet.NewPool(),
 		buf:  bytes.NewBuffer(make([]byte, 0, 4096)),
 		hdr:  &packet.Header{},
@@ -95,7 +99,7 @@ func (c *Client) ReadPacket() (pk packet.Packet, err error) {
 			err = fmt.Errorf("%T: %w", pk, recoveredErr.(error))
 		}
 	}()
-	pk.Unmarshal(protocol.NewReader(buf, 0))
+	pk.Unmarshal(protocol.NewReader(buf, 0, c.readerLimits))
 	if buf.Len() > 0 {
 		return nil, fmt.Errorf("still have %v bytes unread", buf.Len())
 	}

socket/server.go

@@ -39,8 +39,9 @@ type Server interface {
 type DefaultServer struct {
 	log internal.Logger
 
-	addr   string
-	secret string
+	addr         string
+	secret       string
+	readerLimits bool
 
 	listener           net.Listener
 	clientsMu          sync.RWMutex
@@ -52,12 +53,13 @@ type DefaultServer struct {
 }
 
 // NewDefaultServer creates a new default server to be used for accepting socket connections.
-func NewDefaultServer(addr, secret string, sessionStore *session.Store, serverRegistry *server.Registry, log internal.Logger) *DefaultServer {
+func NewDefaultServer(addr, secret string, sessionStore *session.Store, serverRegistry *server.Registry, log internal.Logger, readerLimits bool) *DefaultServer {
 	return &DefaultServer{
 		log: log,
 
-		addr:   addr,
-		secret: secret,
+		addr:         addr,
+		secret:       secret,
+		readerLimits: readerLimits,
 
 		clients:            make(map[string]*Client),
 		unconnectedClients: make(map[net.Addr]*Client),
@@ -85,7 +87,7 @@ func (s *DefaultServer) Listen() error {
 			}
 			s.log.Debugf("socket server accepted a new connection")
 
-			go s.handleClient(NewClient(conn, s.log))
+			go s.handleClient(NewClient(conn, s.log, s.readerLimits))
 		}
 	}()
 	return nil