From 3679d7facc57ebfc59f78fd34e163c3a6189aba9 Mon Sep 17 00:00:00 2001
From: Isaku Yamahata <yamahata@valinux.co.jp>
Date: Mon, 1 Jul 2013 14:53:32 +0900
Subject: [PATCH] lib/packet: make packet_base.parser abstract method

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
 ryu/lib/packet/packet_base.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ryu/lib/packet/packet_base.py b/ryu/lib/packet/packet_base.py
index 847e5ce7..c3f76e31 100644
--- a/ryu/lib/packet/packet_base.py
+++ b/ryu/lib/packet/packet_base.py
@@ -13,9 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import abc
+
 
 class PacketBase(object):
     """A base class for a protocol (ethernet, ipv4, ...) header."""
+    __metaclass__ = abc.ABCMeta
     _TYPES = {}
 
     @classmethod
@@ -43,6 +46,7 @@ class PacketBase(object):
         return self.__class__.__name__
 
     @classmethod
+    @abc.abstractmethod
     def parser(cls, buf):
         """Decode a protocol header.