diff --git a/tools/misc/tcp_template.py b/tools/misc/tcp_template.py
old mode 100644
new mode 100755
index e7f6163..b3b5f39
--- a/tools/misc/tcp_template.py
+++ b/tools/misc/tcp_template.py
@@ -101,6 +101,17 @@ if __name__ == "__main__":
     start_proxy({repr(listen_address)}, {listen_port}, {repr(remote_host)}, {remote_port})
 """
 
+def port(value):
+    try:
+        value = int(value)
+    except ValueError:
+        raise argparse.ArgumentTypeError(f"{value!r} is not a valid integer")
+
+    if not (1 <= value <= 65535):
+        raise argparse.ArgumentTypeError("port must be between 1 and 65535")
+
+    return value
+
 if __name__ == "__main__":
 
     parser = argparse.ArgumentParser(
@@ -109,9 +120,9 @@ if __name__ == "__main__":
     )
 
     parser.add_argument("la", type=str, help="Listen Address")
-    parser.add_argument("lp", type=int, help="Listen Port", choices=range(1,65535+1))
+    parser.add_argument("lp", type=port, help="Listen Port")
     parser.add_argument("rh", type=str, help="Remote Host")
-    parser.add_argument("rp", type=int, help="Remote Port", choices=range(1,65535+1))
+    parser.add_argument("rp", type=port, help="Remote Port")
 
     args = parser.parse_args()
     template = generate_template(args.la, args.lp, args.rh, args.rp)
diff --git a/utils/packeter.py b/utils/packeter.py
index f150ea8..580cdaa 100644
--- a/utils/packeter.py
+++ b/utils/packeter.py
@@ -73,11 +73,11 @@ class Parser(Buffer):
         value = struct.unpack(self._endian(big_endian) + f, self._read(size))[0]
         return value
 
-    def read_byte(self):
+    def read_byte(self, big_endian=None):
         return self._struct_unpack(big_endian, "c")
 
-    def read_char(self):
-        return chr(self.read_byte())
+    def read_char(self, big_endian=None):
+        return chr(self.read_byte(big_endian))
 
     def read_signed_short(self, big_endian=None):
         return self._struct_unpack(big_endian, "h")
@@ -109,7 +109,7 @@ class Parser(Buffer):
             data += c
         return data
 
-class Packer(StructWrapper):
+class Packer(Buffer):
     def __init__(self, big_endian=False):
         super().__init__(b"")
         self.big_endian = big_endian
@@ -120,12 +120,15 @@ class Packer(StructWrapper):
             big_endian = self.big_endian
 
         size = self._format_size(f)
-        self.write(struct.pack(self._endian(big_endian) + f, value))
+        self._write(struct.pack(self._endian(big_endian) + f, value))
+
+    def write_byte(self, value, big_endian=None):
+        if isinstance(value, int):
+            value = bytes([value])
 
-    def write_byte(self, value):
         self._struct_pack(big_endian, "c", value)
 
-    def write_char(self, value):
+    def write_char(self, value, big_endian=None):
         self._struct_pack(big_endian, "c", value.encode())
 
     def write_signed_short(self, value, big_endian=None):
@@ -135,25 +138,28 @@ class Packer(StructWrapper):
         self._struct_pack(big_endian, "H", value)
 
     def write_signed_int(self, value, big_endian=None):
-        self._struct_unpack(big_endian, "i", value)
+        self._struct_pack(big_endian, "i", value)
 
     def write_unsigned_int(self, value, big_endian=None):
-        self._struct_unpack(big_endian, "I", value)
+        self._struct_pack(big_endian, "I", value)
 
     def write_signed_long(self, value, big_endian=None):
-        self._struct_unpack(big_endian, "q", value)
+        self._struct_pack(big_endian, "q", value)
 
     def rwrite_unsigned_long(self, value, big_endian=None):
-        self._struct_unpack(big_endian, "Q", value)
+        self._struct_pack(big_endian, "Q", value)
 
     def write_bin(self, value):
-        self.write(value)
+        self._write(value)
+
+    def write_bytes(self, value):
+        self._write(value)
 
     def write_string(self, value, encoding="UTF-8"):
-        self.write_bin(value.encode(encoding))
+        self._write_bin(value.encode(encoding))
 
     def fill(self, b: bytes, n: int):
-        self.write_bin(b * n)
+        self._write_bin(b * n)
 
     def crc32(self) -> int:
         return zlib.crc32(self.get()) & 0xFFFFFFFF