bgp: fix bug of accessing dead socket

BGP session can be closed by sending inappropriate messages.
So touching socket by get_peername() after sending messages may cause an
exception. Though we can handle this by try..exception, I fixed to simply
call get_peername() before sending messages because session disconnection by
sending messages is an ordinary procedure and not an exception(the peer will
send notification before disconnection).

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 6 insertions, 3 deletions

diff --git a/ryu/services/protocols/bgp/speaker.py b/ryu/services/protocols/bgp/speaker.py
index a0e2ae57..dc828d18 100644
--- a/ryu/services/protocols/bgp/speaker.py
+++ b/ryu/services/protocols/bgp/speaker.py
@@ -371,15 +371,18 @@ class BgpProtocol(Protocol, Activity):
             raise BgpProtocolException('Tried to send message to peer when '
                                        'this protocol instance is not started'
                                        ' or is no longer is started state.')
+        # get peername before senging msg because sending msg can occur
+        # conncetion lost
+        peername = self.get_peername()
         self._socket.sendall(msg.serialize())
+
         if msg.type == BGP_MSG_NOTIFICATION:
             LOG.error('Sent notification to %s >> %s' %
-                      (self.get_peername(), msg))
+                      (peername, msg))
 
             self._signal_bus.bgp_notification_sent(self._peer, msg)
-
         else:
-            LOG.debug('Sent msg to %s >> %s' % (self.get_peername(), msg))
+            LOG.debug('Sent msg to %s >> %s' % (peername, msg))
 
     def stop(self):
         Activity.stop(self)