+#
+# NEPI, a framework to manage network experiments
+# Copyright (C) 2014 INRIA
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation;
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# Author: Alina Quereilhac <alina.quereilhac@inria.fr>
+
+import base64
+import cPickle
+import errno
+import logging
+import os
+import socket
+import sys
+
+from optparse import OptionParser, SUPPRESS_HELP
+
+from netnswrapper import NetNSWrapper
+
+[docs]class NetNSWrapperMessage:
+
CREATE = "CREATE"
+
INVOKE = "INVOKE"
+
SET = "SET"
+
GET = "GET"
+
FLUSH = "FLUSH"
+
SHUTDOWN = "SHUTDOWN"
+
+[docs]def handle_message(wrapper, msg_type, args, kwargs):
+
if msg_type == NetNSWrapperMessage.SHUTDOWN:
+
wrapper.shutdown()
+
+
return "BYEBYE"
+
+
if msg_type == NetNSWrapperMessage.CREATE:
+
clazzname = args.pop(0)
+
+
return wrapper.create(clazzname, *args)
+
+
if msg_type == NetNSWrapperMessage.INVOKE:
+
uuid = args.pop(0)
+
operation = args.pop(0)
+
+
return wrapper.invoke(uuid, operation, *args, **kwargs)
+
+
if msg_type == NetNSWrapperMessage.GET:
+
uuid = args.pop(0)
+
name = args.pop(0)
+
+
return wrapper.get(uuid, name)
+
+
if msg_type == NetNSWrapperMessage.SET:
+
uuid = args.pop(0)
+
name = args.pop(0)
+
value = args.pop(0)
+
+
return wrapper.set(uuid, name, value)
+
+
if msg_type == NetNSWrapperMessage.FLUSH:
+
# Forces flushing output and error streams.
+
# NS-3 output will stay unflushed until the program exits or
+
# explicit invocation flush is done
+
sys.stdout.flush()
+
sys.stderr.flush()
+
+
wrapper.logger.debug("FLUSHED")
+
+
return "FLUSHED"
+
+[docs]def create_socket(socket_name):
+
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+
sock.bind(socket_name)
+
return sock
+
+[docs]def recv_msg(conn):
+
msg = []
+
chunk = ''
+
+
while '\n' not in chunk:
+
try:
+
chunk = conn.recv(1024)
+
except (OSError, socket.error), e:
+
if e[0] != errno.EINTR:
+
raise
+
# Ignore eintr errors
+
continue
+
+
if chunk:
+
msg.append(chunk)
+
else:
+
# empty chunk = EOF
+
break
+
+
msg = ''.join(msg).strip()
+
+
# The message is formatted as follows:
+
# MESSAGE_TYPE|args|kwargs
+
#
+
# where MESSAGE_TYPE, args and kwargs are pickld and enoded in base64
+
+
def decode(item):
+
item = base64.b64decode(item).rstrip()
+
return cPickle.loads(item)
+
+
decoded = map(decode, msg.split("|"))
+
+
# decoded message
+
dmsg_type = decoded.pop(0)
+
dargs = list(decoded.pop(0)) # transforming touple into list
+
dkwargs = decoded.pop(0)
+
+
return (dmsg_type, dargs, dkwargs)
+
+[docs]def send_reply(conn, reply):
+
encoded = base64.b64encode(cPickle.dumps(reply))
+
conn.send("%s\n" % encoded)
+
+[docs]def get_options():
+
usage = ("usage: %prog -S <socket-name> -D <enable-dump> -v ")
+
+
parser = OptionParser(usage = usage)
+
+
parser.add_option("-S", "--socket-name", dest="socket_name",
+
help = "Name for the unix socket used to interact with this process",
+
default = "tap.sock", type="str")
+
+
parser.add_option("-D", "--enable-dump", dest="enable_dump",
+
help = "Enable dumping the remote executed commands to a script "
+
"in order to later reproduce and debug the experiment",
+
action = "store_true",
+
default = False)
+
+
parser.add_option("-v", "--verbose",
+
help="Print debug output",
+
action="store_true",
+
dest="verbose", default=False)
+
+
(options, args) = parser.parse_args()
+
+
return (options.socket_name, options.verbose, options.enable_dump)
+
+[docs]def run_server(socket_name, level = logging.INFO,
+
enable_dump = False):
+
+
###### wrapper instantiation
+
if level == logging.DEBUG:
+
from syslog import LOG_DEBUG
+
import netns
+
netns.environ.set_log_level(LOG_DEBUG)
+
+
wrapper = NetNSWrapper(loglevel=level, enable_dump = enable_dump)
+
+
wrapper.logger.info("STARTING...")
+
+
# create unix socket to receive instructions
+
sock = create_socket(socket_name)
+
sock.listen(0)
+
+
# wait for messages to arrive and process them
+
stop = False
+
+
while not stop:
+
conn, addr = sock.accept()
+
conn.settimeout(5)
+
+
try:
+
(msg_type, args, kwargs) = recv_msg(conn)
+
except socket.timeout, e:
+
# Ingore time-out
+
continue
+
+
if not msg_type:
+
# Ignore - connection lost
+
break
+
+
if msg_type == NetNSWrapperMessage.SHUTDOWN:
+
stop = True
+
+
try:
+
reply = handle_message(wrapper, msg_type, args, kwargs)
+
except:
+
import traceback
+
err = traceback.format_exc()
+
wrapper.logger.error(err)
+
raise
+
+
try:
+
send_reply(conn, reply)
+
except socket.error:
+
break
+
+
wrapper.logger.info("EXITING...")
+
+if __name__ == '__main__':
+
+ (socket_name, verbose, enable_dump) = get_options()
+
+ ## configure logging
+ FORMAT = "%(asctime)s %(name)s %(levelname)-4s %(message)s"
+ level = logging.DEBUG if verbose else logging.INFO
+
+ logging.basicConfig(format = FORMAT, level = level)
+
+ ## Run the server
+ run_server(socket_name, level, enable_dump)
+