packet lib: Add packet library of OpenFlow

Signed-off-by: Shinpei Muraoka <shinpei.muraoka@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

ryu/lib/packet/openflow.py

@@ -0,0 +1,113 @@
+# Copyright (C) 2017 Nippon Telegraph and Telephone Corporation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import struct
+
+from ryu.lib import stringify
+from . import packet_base
+
+
+class openflow(packet_base.PacketBase):
+    """OpenFlow message encoder/decoder class.
+
+    An instance has the following attributes at least.
+
+    ============== =========================================================
+    Attribute      Description
+    ============== =========================================================
+    msg            An instance of OpenFlow message (see :ref:`ofproto_ref`)
+                   or an instance of OFPUnparseableMsg if failed to parse
+                   packet as OpenFlow message.
+    ============== =========================================================
+    """
+
+    PACK_STR = '!BBHI'
+    _MIN_LEN = struct.calcsize(PACK_STR)
+
+    def __init__(self, msg):
+        super(openflow, self).__init__()
+        self.msg = msg
+
+    @classmethod
+    def parser(cls, buf):
+        from ryu.ofproto import ofproto_parser
+        from ryu.ofproto import ofproto_protocol
+
+        (version, msg_type, msg_len, xid) = ofproto_parser.header(buf)
+
+        msg_parser = ofproto_parser._MSG_PARSERS.get(version)
+        if msg_parser is None:
+            msg = OFPUnparseableMsg(
+                None, version, msg_type, msg_len, xid,
+                buf[cls._MIN_LEN:msg_len])
+            return cls(msg), cls, buf[msg_len:]
+
+        datapath = ofproto_protocol.ProtocolDesc(version=version)
+
+        try:
+            msg = msg_parser(datapath, version, msg_type, msg_len, xid,
+                             buf[:msg_len])
+        except:
+            msg = OFPUnparseableMsg(
+                datapath, version, msg_type, msg_len, xid,
+                buf[datapath.ofproto.OFP_HEADER_SIZE:msg_len])
+
+        return cls(msg), cls, buf[msg_len:]
+
+    def serialize(self, _payload, _prev):
+        self.msg.serialize()
+        return self.msg.buf
+
+
+class OFPUnparseableMsg(stringify.StringifyMixin):
+    """Unparseable OpenFlow message encoder class.
+
+    An instance has the following attributes at least.
+
+    ============== ======================================================
+    Attribute      Description
+    ============== ======================================================
+    datapath       A ryu.ofproto.ofproto_protocol.ProtocolDesc instance
+                   for this message or None if OpenFlow protocol version
+                   is unsupported version.
+    version        OpenFlow protocol version
+    msg_type       Type of OpenFlow message
+    msg_len        Length of the message
+    xid            Transaction id
+    body           OpenFlow body data
+    ============== ======================================================
+
+    .. Note::
+
+        "datapath" attribute is different from
+        ryu.controller.controller.Datapath.
+        So you can not use "datapath" attribute to send OpenFlow messages.
+        For example, "datapath" attribute does not have send_msg method.
+    """
+
+    def __init__(self, datapath, version, msg_type, msg_len, xid, body):
+        self.datapath = datapath
+        self.version = version
+        self.msg_type = msg_type
+        self.msg_len = msg_len
+        self.xid = xid
+        self.body = body
+        self.buf = None
+
+    def serialize(self):
+        self.buf = struct.pack(
+            openflow.PACK_STR,
+            self.version, self.msg_type, self.msg_len, self.xid)
+        self.buf += self.body

ryu/lib/packet/tcp.py

@@ -20,6 +20,7 @@ import logging
 from . import packet_base
 from . import packet_utils
 from . import bgp
+from . import openflow
 from ryu.lib import stringify
 
 
@@ -111,8 +112,12 @@ class tcp(packet_base.PacketBase):
 
     @staticmethod
     def get_payload_type(src_port, dst_port):
+        from ryu.ofproto.ofproto_common import OFP_TCP_PORT, OFP_SSL_PORT_OLD
         if bgp.TCP_SERVER_PORT in [src_port, dst_port]:
             return bgp.BGPMessage
+        elif(src_port in [OFP_TCP_PORT, OFP_SSL_PORT_OLD] or
+             dst_port in [OFP_TCP_PORT, OFP_SSL_PORT_OLD]):
+            return openflow.openflow
         else:
             return None