1

#!/usr/bin/env python

     2

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

     3

     4

# This file is part of Beremiz runtime.

     5

#

     6

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

     7

#

     8

# See COPYING.Runtime file for copyrights details.

     9

#

    10

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

    11

# modify it under the terms of the GNU Lesser General Public

    12

# License as published by the Free Software Foundation; either

    13

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

    14

    15

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

    16

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

    17

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

    18

# Lesser General Public License for more details.

    19

    20

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

    21

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

    22

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

    23

    24

    25

from __future__ import absolute_import

    26

from __future__ import print_function

    27

import socket

    28

import threading

    29

import zeroconf

    30

    31

    32

service_type = '_Beremiz._tcp.local.'

    33

    34

    35

class ServicePublisher(object):

    36

    def __init__(self, protocol):

    37

        # type: fully qualified service type name

    38

        self.serviceproperties = {

    39

            'description': 'Beremiz remote PLC',

    40

            'protocol': protocol

    41

        }

    42

    43

        self.name = None

    44

        self.ip_32b = None

    45

        self.port = None

    46

        self.server = None

    47

        self.service_name = None

    48

        self.retrytimer = None

    49

    50

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

    51

        try:

    52

            self._RegisterService(name, ip, port)

    53

        except Exception:

    54

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

    55

            self.retrytimer.start()

    56

    57

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

    58

        # name: fully qualified service name

    59

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

    60

        self.name = name

    61

        self.port = port

    62

    63

        if ip == "0.0.0.0":

    64

            print("MDNS brodcasted on all interfaces")

    65

            interfaces = zeroconf.InterfaceChoice.All

    66

            ip = self.gethostaddr()

    67

        else:

    68

            interfaces = [ip]

    69

    70

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

    71

    72

        print("MDNS brodcasted service address :" + ip)

    73

        self.ip_32b = socket.inet_aton(ip)

    74

    75

        self.server.register_service(

    76

            zeroconf.ServiceInfo(service_type,

    77

                                 self.service_name,

    78

                                 self.ip_32b,

    79

                                 self.port,

    80

                                 properties=self.serviceproperties))

    81

        self.retrytimer = None

    82

    83

    def UnRegisterService(self):

    84

        if self.retrytimer is not None:

    85

            self.retrytimer.cancel()

    86

    87

        if self.server is not None:

    88

            self.server.unregister_service(

    89

                zeroconf.ServiceInfo(service_type,

    90

                                     self.service_name,

    91

                                     self.ip_32b,

    92

                                     self.port,

    93

                                     properties=self.serviceproperties))

    94

            self.server.close()

    95

            self.server = None

    96

    97

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

    98

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

    99

        try:

   100

            s.connect((dst, 7))

   101

            (host, _port) = s.getsockname()

   102

            s.close()

   103

            if host != '0.0.0.0':

   104

                return host

   105

        except Exception:

   106

            pass

   107

        return socket.gethostbyname(socket.gethostname())