very basic implementation of a TCP (socket) protocl server

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# "@(#) $Id$"

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# Makefile of ........

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# who       when      what

# --------  --------  ----------------------------------------------

# andrea  13/10/16  created

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# Python stuff (public and local)

# ----------------------------

PY_SCRIPTS         = tcpProt-sim

PY_PACKAGES        = TCPGenericProtocolSimImpl

#

# list of all possible C-sources (used to create automatic dependencies)

# ------------------------------

CSOURCENAMES = \

	$(foreach exe, $(EXECUTABLES) $(EXECUTABLES_L), $($(exe)_OBJECTS)) \

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	$(foreach lib, $(LIBRARIES) $(LIBRARIES_L), $($(lib)_OBJECTS))

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# INCLUDE STANDARDS

# -----------------

MAKEDIRTMP := $(shell searchFile include/acsMakefile)

ifneq ($(MAKEDIRTMP),\#error\#)

   MAKEDIR := $(MAKEDIRTMP)/include

   include $(MAKEDIR)/acsMakefile

endif

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# TARGETS

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	@echo " . . . 'all' done" 

clean : clean_all 

	@echo " . . . clean done"

clean_dist : clean_all clean_dist_all 

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man   : do_man 

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install : install_all

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#___oOo___

#!/usr/bin/env python

# Author: Andrea Orlati <a.orlati@ira.inaf.it>

# **************************************************************************************************** 

# DISCOS Project                                                                                       

#                                                                                                      

# This code is under GNU General Public License (GPL).             

# Who                                when            What                          

# Andrea Orlati(aorlati@ira.inaf.it) 13/10/2016     Creation                                       

"""

This module provides a dummy server  a dummy server. 

How To Use This Module

======================

(See the individual classes, methods, and attributes for details)

1. Import it: ``import TCPServer``

2. Create a BoardServer object::

       rs = TCPServer(cmd, answ, defAnsw)

3. Run the server::

       rs.run()

An alternative way is to execute directly this module from a shell::

       ./TCPserver.py

To stop the server::

       rs.stop()

"""

import socket, traceback, os, sys

import binhex

from multiprocessing import Value

stop_server = Value('i', False)

class TCPServer:

	def __init__(self, cmd, answ, defAnsw):

		"""

		Initialize

   	Parameters:

		- `cmd`: a strings or commands that the server recognizes

		- 'answ': server answers to the defined commands

		- 'defAnsw': a string sent as answer to the clinet in case the command is not recognized

		- `port`: the port the server is listening for connections.

		"""

		self.host = socket.gethostbyname(socket.gethostname())

		self.port = 15001

		self.command=cmd

		self.answer=answ

		self.defaultAnswer=defAnsw

		self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

		self.s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

	def run(self):

		self.s.bind((self.host, self.port))

		self.s.listen(1)

		print "*"*40

		print "TCPServer - Waiting for connections from %s port %d..." % (self.host,self.port)

		print "Valid commands are: %s" % (self.command)

		print "*"*40

		error=False

		try:

			connection, clientaddr = self.s.accept()

			print "Got connection from %s port %d" % (connection.getpeername())

		except KeyboardInterrupt:

			raise			

		except:

			error=True

		finally:

			self.s.close()

		if error:

			sys.exit(0)

		try:

			while True:

				if stop_server.value:

					break

				data = connection.recv(1024)

				if '#stop' in data:

					stop_server.value = True

					connection.close()

					break

				if(data):

					answer=self.defaultAnswer

					if len(data)> 1:

						strcmp=data.strip()

						print "Received: %s" % (strcmp)

						if strcmp in self.command:

							index=self.command.index(strcmp)

							answer=self.answer[index]

					print "Sending message: %s" % (answer)

					connection.send(answer)			

		except KeyboardInterrupt:

			raise

		except:

			pass

		finally:

			connection.close()

		print "Exiting...."

		sys.exit(0)

	@staticmethod

	def stop():

		print "shutdown by external command..."

		stop_server.value = True

if __name__ == "__main__":

	bs = TCPServer()

	bs.run()

#!/usr/bin/env python

import argparse

import signal

import sys

import os

from TCPGenericProtocolSimImpl.TCPServer import TCPServer

parser = argparse.ArgumentParser(description="Start/Stop the TCP server")

parser.add_argument('action', choices=['start', 'stop'])

parser.add_argument('--cmd', action='append',dest='commands',default=[],help='Add repeated commands')

parser.add_argument('--ans', action='append',dest='answers',default=[],help='Add repeated answers')

parser.add_argument('--def', dest='defVal',default='',help='default answer')

args = parser.parse_args()

def handle_signal(num, trace):

	TCPServer.stop()

if __name__ == "__main__":

	if args.action == 'start':

		signal.signal(signal.SIGINT,handle_signal)     

		signal.signal(signal.SIGUSR1,handle_signal) 

		server = TCPServer(args.commands,args.answers,args.defVal)

		server.run()

	elif args.action == 'stop':

		for line in os.popen("ps ax | grep " + sys.argv[0] + " | grep -v grep"):

			fields = line.split()

			pid = fields[0]

			if int(pid) != os.getpid():

				os.kill(int(pid), signal.SIGINT)