asrc-dev/asrc-server.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#  
#  
#  asrc-server.py
#  
#  Copyright 2012 - 2013 Fanir-Thuban <projects@mail.fanir.de>
#  
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#  
#  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, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#  
#  
#  aSRC (Aliased Server Remote Control)
#  - SERVER -
#  
#  program version: 0.0.0.20130423
#  protocol version: 0.2.20130423
#  
#



import sys, os, socket, socketserver, threading, time


def motd():
	return MOTD


def content(client_address, data):
	ret = ""
	
	ret = ret +
		"{BEGIN}\n"\
		"asrcp" + ProtocolVersion + "\n"
	
	# Look if the received message is an
	# valid alias or a predefined command
	
	# if it's 'version', return the server and protocol version
	if data == "version":
		
		if DEBUGLEVEL >= 2: print("Got valid service command from"
			+ str(client_address) + ": ", data)
		
		ret = ret + 
			"202 Valid Service Command\n"\
			"002 Version\n"\
			"ServerVersion:" + ServerVersion + "\n"\
			"ProtocolVersion:" + ProtocolVersion + "\n"
	
	# if it's 'help', give a little help
	elif data == 'help':
		
		if DEBUGLEVEL >= 2: print("Got valid command from"
			+ str(client_address) + ": ", data)
		
		# send status code
		ret = ret + "202 Valid Service Command\n\n"
		
		# send the list of aliases
		ret = ret + "Aviable aliases:\n"
		for i in aliases.keys():
			ret = ret + str(i) + "\n"
	
	# if it's a valid userdefined command
	elif data in aliases:
		
		# send status code
		ret = ret + "201 Valid Command\n\n"
		
		# ohmagawd! a debug message!!1!
		if DEBUGLEVEL >= 2: print("Got valid command from"
			+ str(client_address) + ": ", data)
		
		# execute the aliased command
		g_dict, l_dict = {}, {}
		exec(str(aliases[data]), g_dict, l_dict)
		
		# send may contain data to send to the client
		if l_dict["send"]:
				content = str(l_dict["send"]).replace('{', '\{')
				content = content.replace('}', '\}')
				
				ret = ret + content + "\n"
	
	# ALL IS LOST!!1! this has to be invalid!
	else:
		
		# send status code
		ret = ret + "203 Invalid Command\n"
		
		if DEBUGLEVEL >= 2: print("Got invalid command from",
			str(client_address), ": ", data)
	
	ret = ret + "{END}\n"
	
	return ret


class ThreadedRequestHandler(socketserver.StreamRequestHandler):
	
	def handle(self):
		
		# Set time for timeout in seconds
		self.timeout = TIMEOUT
		
		# Print a line with the adress of the connected client
		if DEBUGLEVEL >=3:
			print("Client connected: " + str(self.client_address))
		
		# send header line 1
		self.request.sendall(bytes
			("asrpc " + ProtocolVersion + "\n", ENCODING))
		
		# send motd
		self.request.sendall(bytes(motd() + "\n", ENCODING))
		
		# Receive data
		self.data = str(self.rfile.readline().strip(), ENCODING)
		
		# content handler
		self.request.sendall(bytes(
			content(str(self.client_address), self.data), ENCODING))


class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
	pass


def main():
	print("aSRC Server\n"\
	"Server version: " + ServerVersion + "\n"\
	"Protocol version: " + ProtocolVersion + "\n\n"\
	"To stop the server, press Ctrl-C\n")
	
	try:
		if DEBUGLEVEL >= 1: print("Initializing server...")
		# Create server
		server = ThreadedTCPServer((HOST, PORT), ThreadedRequestHandler)
		
		if DEBUGLEVEL >= 1: print("Starting server on",
			server.server_address[0], "port", server.server_address[1], "...")
		# Start a thread with the server -- that thread will then start one
		# more thread for each request
		ServerThread = threading.Thread(target = server.serve_forever)
		
		# Exit the server thread when the main thread terminates
		ServerThread.daemon = True
		ServerThread.start()
		while True:
			time.sleep(10)
		
	except KeyboardInterrupt:
		print("\nGot Ctrl-C, shutting down server...")
		
		try: server.shutdown()
		except: print("Failed to shutdown server correctly, "\
				"socket may be still in use or wasn't even started:",
				sys.exc_info())
	except:
		print("\nAn error occured:\n", sys.exc_info(), "\n")
	
			
	if DEBUGLEVEL >= 3: input("Press Enter to continue\n")
	return 0


if __name__ == '__main__':
	
	ServerVersion = "0.0.0"
	ProtocolVersion = "0.2"
	
	
	##############
	#  SETTINGS  #
	##############
	
	# IP or hostname (use 0.0.0.0 for all interfaces) and port, on which
	# the server should listen
	HOST = '127.0.0.1'
	PORT = 24642
	
	# Timeout of a connection in seconds - obviously still doesn't work...
	TIMEOUT = 4
	
	# Encoding to be used when communicating with a client
	ENCODING = 'utf-8'
	
	# Dictionary of aliases. Use python syntax. You can use
	# the variable send for text to send to the client.
	#
	# Shell commands can be executed with:
	#     import subprocess
	#     send = subprocess.check_output(["command", "arg", "somemorearg"])
	#
	# You don't have to include sys, os, socket, socketserver,
	# threading and time, through they are included already.
	aliases = dict(
		who = '''
import subprocess
send = subprocess.check_output(["whoami"])
''',
		where = '''
import subprocess
send = subprocess.check_output(["pwd"])
''',
		uname = '''
import os
send = os.uname()
''',
		date = '''
import subprocess
send = subprocess.check_output(["date"])
''',
		ping_fanir = '''
import subprocess
send = subprocess.check_output(["ping", "-c 2", "fanir.de"])
''')
	
	# This is sent to the client after the connection is established
	MOTD = "Welcome! This is only a test server, for developing purposes.\n"\
	"Here (may) be more text..."
	
	# Verbosity of logging.
	# Can be from 0 (only default output) to 3 (debug messages)
	DEBUGLEVEL = 3
	##############
	
	
	main()