ofproto: Encode data field on OFPErrorMsg

Currently, when Ryu failed to negotiate the OpenFlow version with a
switch, Ryu will send the OFPT_ERROR message with an error reason on its
data field.
But on Python 3, error reason string is a str type value and required to
be encoded into a bytes type value, otherwise causes an exception when
sending the message.

This patch fixes to encode the given str value into a bytes type value
in OFPErrorMsg.__init__() and solves this problem.

Signed-off-by: William Fisher <william.w.fisher@gmail.com>
Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

ryu/controller/ofp_handler.py

@@ -60,11 +60,12 @@ class OFPHandler(ryu.base.app_manager.RyuApp):
         return hub.spawn(self.controller)
 
     def _hello_failed(self, datapath, error_desc):
-        self.logger.error(error_desc)
-        error_msg = datapath.ofproto_parser.OFPErrorMsg(datapath)
-        error_msg.type = datapath.ofproto.OFPET_HELLO_FAILED
-        error_msg.code = datapath.ofproto.OFPHFC_INCOMPATIBLE
-        error_msg.data = error_desc
+        self.logger.error('%s on datapath %s', error_desc, datapath.address)
+        error_msg = datapath.ofproto_parser.OFPErrorMsg(
+            datapath=datapath,
+            type_=datapath.ofproto.OFPET_HELLO_FAILED,
+            code=datapath.ofproto.OFPHFC_INCOMPATIBLE,
+            data=error_desc)
         datapath.send_msg(error_msg, close_socket=True)
 
     @set_ev_handler(ofp_event.EventOFPHello, HANDSHAKE_DISPATCHER)

ryu/ofproto/ofproto_v1_0_parser.py

@@ -1258,6 +1258,8 @@ class OFPErrorMsg(MsgBase):
         super(OFPErrorMsg, self).__init__(datapath)
         self.type = type_
         self.code = code
+        if isinstance(data, six.string_types):
+            data = data.encode('ascii')
         self.data = data
 
     @classmethod

ryu/ofproto/ofproto_v1_2_parser.py

@@ -141,6 +141,8 @@ class OFPErrorMsg(MsgBase):
         super(OFPErrorMsg, self).__init__(datapath)
         self.type = type_
         self.code = code
+        if isinstance(data, six.string_types):
+            data = data.encode('ascii')
         self.data = data
         if self.type == ofproto.OFPET_EXPERIMENTER:
             self.exp_type = kwargs.get('exp_type', None)

ryu/ofproto/ofproto_v1_3_parser.py

@@ -251,6 +251,8 @@ class OFPErrorMsg(MsgBase):
         super(OFPErrorMsg, self).__init__(datapath)
         self.type = type_
         self.code = code
+        if isinstance(data, six.string_types):
+            data = data.encode('ascii')
         self.data = data
         if self.type == ofproto.OFPET_EXPERIMENTER:
             self.exp_type = kwargs.get('exp_type', None)

ryu/ofproto/ofproto_v1_4_parser.py

@@ -262,6 +262,8 @@ class OFPErrorMsg(MsgBase):
         super(OFPErrorMsg, self).__init__(datapath)
         self.type = type_
         self.code = code
+        if isinstance(data, six.string_types):
+            data = data.encode('ascii')
         self.data = data
         if self.type == ofproto.OFPET_EXPERIMENTER:
             self.exp_type = kwargs.get('exp_type', None)

ryu/ofproto/ofproto_v1_5_parser.py

@@ -262,6 +262,8 @@ class OFPErrorMsg(MsgBase):
         super(OFPErrorMsg, self).__init__(datapath)
         self.type = type_
         self.code = code
+        if isinstance(data, six.string_types):
+            data = data.encode('ascii')
         self.data = data
         if self.type == ofproto.OFPET_EXPERIMENTER:
             self.exp_type = kwargs.get('exp_type', None)