bgp: use sendall with lock

With the current design, multiple greenlets calls sendall() on a
single tcp socket. This leads to a corrupted bgp message.

This patch introduces mutex to work around the problem. However, I
hope that we _fix_ the design where only one greenlet call sendall()
on a signel tcp socket in the future.

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

1 files changed, 11 insertions, 2 deletions

diff --git a/ryu/services/protocols/bgp/speaker.py b/ryu/services/protocols/bgp/speaker.py
index d5a543ad..e4a9bc92 100644
--- a/ryu/services/protocols/bgp/speaker.py
+++ b/ryu/services/protocols/bgp/speaker.py
@@ -21,6 +21,7 @@ import socket
 import struct
 import traceback
 from socket import IPPROTO_TCP, TCP_NODELAY
+from eventlet import semaphore
 
 from ryu.lib.packet import bgp
 from ryu.lib.packet.bgp import RouteFamily
@@ -104,6 +105,7 @@ class BgpProtocol(Protocol, Activity):
         self._recv_buff = ''
         self._socket = socket
         self._socket.setsockopt(IPPROTO_TCP, TCP_NODELAY, 1)
+        self._sendlock = semaphore.Semaphore()
         self._signal_bus = signal_bus
         self._holdtime = None
         self._keepalive = None
@@ -362,7 +364,7 @@ class BgpProtocol(Protocol, Activity):
         """
         notification = BGPNotification(code, subcode)
         reason = notification.reason
-        self._socket.sendall(notification.serialize())
+        self._send_with_lock(notification)
         self._signal_bus.bgp_error(self._peer, code, subcode, reason)
         LOG.error(
             'Sent notification to %r >> %s' %
@@ -370,6 +372,13 @@ class BgpProtocol(Protocol, Activity):
         )
         self._socket.close()
 
+    def _send_with_lock(self, msg):
+        self._sendlock.acquire()
+        try:
+            self._socket.sendall(msg.serialize())
+        finally:
+            self._sendlock.release()
+
     def send(self, msg):
         if not self.started:
             raise BgpProtocolException('Tried to send message to peer when '
@@ -378,7 +387,7 @@ class BgpProtocol(Protocol, Activity):
         # get peername before senging msg because sending msg can occur
         # conncetion lost
         peername = self.get_peername()
-        self._socket.sendall(msg.serialize())
+        self._send_with_lock(msg)
 
         if msg.type == BGP_MSG_NOTIFICATION:
             LOG.error('Sent notification to %s >> %s' %