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#!/usr/bin/env python

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# -*- coding: utf-8 -*-

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#This file is part of Beremiz, a Integrated Development Environment for

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#programming IEC 61131-3 automates supporting plcopen standard and CanFestival. 

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#

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#Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD

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#

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#See COPYING file for copyrights details.

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#

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#This library is free software; you can redistribute it and/or

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#modify it under the terms of the GNU General Public

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#License as published by the Free Software Foundation; either

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#version 2.1 of the License, or (at your option) any later version.

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#

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#This library is distributed in the hope that it will be useful,

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#but WITHOUT ANY WARRANTY; without even the implied warranty of

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#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

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#General Public License for more details.

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#

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#You should have received a copy of the GNU General Public

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#License along with this library; if not, write to the Free Software

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#Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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import Zeroconf, socket, threading

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class ServicePublisher():

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    def __init__(self):

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        # type: fully qualified service type name

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        self.service_type = '_PYRO._tcp.local.'

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        # properties: dictionary of properties (or a string holding the bytes for the text field)

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        self.serviceproperties = {'description':'Beremiz remote PLC'}

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        self.name = None

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        self.ip_32b = None

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        self.port = None

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        self.server = None

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        self.service_name = None

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        self.retrytimer = None

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    def RegisterService(self, name, ip, port):

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        try:

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            self._RegisterService(name, ip, port)

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        except Exception,e:

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            self.retrytimer = threading.Timer(2,self.RegisterService,[name, ip, port])

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            self.retrytimer.start() 

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    def _RegisterService(self, name, ip, port):

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        # name: fully qualified service name

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        self.service_name = 'Beremiz_%s.%s'%(name,self.service_type)

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        self.name = name

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        self.port = port

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        self.server = Zeroconf.Zeroconf(ip)

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        print "MDNS brodcasting on :"+ip

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        if ip == "0.0.0.0":

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            ip = self.gethostaddr()

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        print "MDNS brodcasted service address :"+ip

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        self.ip_32b = socket.inet_aton(ip)

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        self.server.registerService(

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             Zeroconf.ServiceInfo(self.service_type,

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                                  self.service_name,

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                                  self.ip_32b,

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                                  self.port,

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                                  properties = self.serviceproperties))

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        self.retrytimer=None

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    def UnRegisterService(self):

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        if self.retrytimer is not None:

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            self.retrytimer.cancel()

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        self.server.unregisterService(

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                                      Zeroconf.ServiceInfo(self.service_type, 

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                                                           self.service_name, 

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                                                           self.ip_32b, 

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                                                           self.port, 

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                                                           properties = self.serviceproperties))

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        self.server.close()

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        self.server = None

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    def gethostaddr(self, dst = '224.0.1.41'):

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        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

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        try:

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            s.connect((dst, 7))

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            (host, port) = s.getsockname()

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            s.close()

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            if host != '0.0.0.0':

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                return host

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        except Exception,e:

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            pass

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        return socket.gethostbyname(socket.gethostname())