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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 runtime.

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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.Runtime 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 Lesser 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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# 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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# Lesser General Public License for more details.

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

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

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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

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import socket

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import threading

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import zeroconf

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service_type = '_Beremiz._tcp.local.'

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class ServicePublisher(object):

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    def __init__(self, protocol):

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        # type: fully qualified service type name

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        self.serviceproperties = {

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            'description': 'Beremiz remote PLC',

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            'protocol': protocol

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        }

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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:

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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 = '%s.%s' % (name, service_type)

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        self.name = name

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        self.port = port

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        if ip == "0.0.0.0":

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            print("MDNS brodcasted on all interfaces")

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            interfaces = zeroconf.InterfaceChoice.All

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            ip = self.gethostaddr()

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        else:

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            interfaces = [ip]

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        self.server = zeroconf.Zeroconf(interfaces=interfaces)

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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.register_service(

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            zeroconf.ServiceInfo(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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        if self.server is not None:

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            self.server.unregister_service(

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                zeroconf.ServiceInfo(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:

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            pass

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        return socket.gethostbyname(socket.gethostname())