require header match

packet.go

@@ -31,11 +31,44 @@ type Packet struct {
 	StatusCode  uint32
 }
 
+var headerData = make([]byte, 4)
+
+func matchHeader(conn io.Reader) error {
+
+	pos := 0
+	for pos < 4 {
+
+		l, err := conn.Read(headerData)
+		if err != nil {
+			return err
+		}
+		for i := 0; i < l; i++ {
+			if headerData[i] == header[pos] {
+				pos++
+				if pos == 4 {
+					return nil
+				}
+			} else {
+				pos = 0
+			}
+		}
+	}
+	return nil
+}
+
 func ReadPacket(conn io.Reader, packet *Packet) error {
+	err := matchHeader(conn)
+	if err != nil {
+		return err
+	}
 	return binary.Read(conn, binary.LittleEndian, packet)
 }
 
 func ReadCartPacket(conn io.Reader, packet *CartPacket) error {
+	err := matchHeader(conn)
+	if err != nil {
+		return err
+	}
 	return binary.Read(conn, binary.LittleEndian, packet)
 }