1

#!/usr/bin/env python

     2

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

     3

     4

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

     5

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

     6

#

     7

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

     8

#

     9

# See COPYING file for copyrights details.

    10

#

    11

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

    12

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

    13

# as published by the Free Software Foundation; either version 2

    14

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

    15

#

    16

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

    17

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

    18

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    19

# GNU General Public License for more details.

    20

#

    21

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

    22

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

    23

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

    24

    25

    26

from __future__ import absolute_import

    27

from __future__ import print_function

    28

import traceback

    29

from time import sleep

    30

import copy

    31

import socket

    32

import os.path

    33

    34

import Pyro

    35

import Pyro.core

    36

import Pyro.util

    37

from Pyro.errors import PyroError

    38

    40

    41

zeroconf_service_type = '_PYRO._tcp.local.'

    42

# this module attribute contains a list of DNS-SD (Zeroconf) service types

    43

# supported by this connector confnode.

    44

#

    45

# for connectors that do not support DNS-SD, this attribute can be omitted

    46

# or set to an empty list.

    47

    48

    49

def PYRO_connector_factory(uri, confnodesroot):

    50

    """

    51

    This returns the connector to Pyro style PLCobject

    52

    """

    53

    confnodesroot.logger.write(_("PYRO connecting to URI : %s\n") % uri)

    54

    55

    scheme, location = uri.split("://")

    56

    if scheme == "PYROS":

    57

        import connectors.PYRO.PSK_Adapter

    58

        schemename = "PYROLOCPSK"

    59

        url, ID = location.split('#') #TODO fix exception when # not found

    60

        # load PSK from project

    61

        secpath = os.path.join(str(confnodesroot.ProjectPath), 'psk', ID+'.secret')

    62

        if not os.path.exists(secpath):

    63

            confnodesroot.logger.write_error(

    64

                'Error: Pre-Shared-Key Secret in %s is missing!\n' % secpath)

    65

            return None

    66

        secret = open(secpath).read().partition(':')[2].rstrip('\n\r')

    67

        Pyro.config.PYROPSK = (secret, ID)

    68

        # strip ID from URL, so that pyro can understand it.

    69

        location = url

    70

    else:

    71

        schemename = "PYROLOC"

    72

    73

    if location.find(zeroconf_service_type) != -1:

    74

        try:

    75

            from zeroconf import Zeroconf

    76

            r = Zeroconf()

    77

            i = r.get_service_info(zeroconf_service_type, location)

    78

            if i is None:

    79

                raise Exception("'%s' not found" % location)

    80

            ip = str(socket.inet_ntoa(i.address))

    81

            port = str(i.port)

    82

            newlocation = ip + ':' + port

    83

            confnodesroot.logger.write(_("'{a1}' is located at {a2}\n").format(a1=location, a2=newlocation))

    84

            location = newlocation

    85

            r.close()

    86

        except Exception:

    87

            confnodesroot.logger.write_error(_("MDNS resolution failure for '%s'\n") % location)

    88

            confnodesroot.logger.write_error(traceback.format_exc())

    89

            return None

    90

    91

    # Try to get the proxy object

    92

    try:

    93

        RemotePLCObjectProxy = Pyro.core.getAttrProxyForURI(schemename + "://" + location + "/PLCObject")

    94

    except Exception,e:

    95

        confnodesroot.logger.write_error(_("Connection to '%s' failed with exception '%s'\n") % (location, str(e)))

    96

        #confnodesroot.logger.write_error(traceback.format_exc())

    97

        return None

    98

    99

    def PyroCatcher(func, default=None):

   100

        """

   101

        A function that catch a Pyro exceptions, write error to logger

   102

        and return default value when it happen

   103

        """

   104

        def catcher_func(*args, **kwargs):

   105

            try:

   106

                return func(*args, **kwargs)

   107

            except Pyro.errors.ConnectionClosedError, e:

   108

                confnodesroot.logger.write_error(_("Connection lost!\n"))

   109

                confnodesroot._SetConnector(None)

   110

            except Pyro.errors.ProtocolError, e:

   111

                confnodesroot.logger.write_error(_("Pyro exception: %s\n") % e)

   112

            except Exception, e:

   113

                # confnodesroot.logger.write_error(traceback.format_exc())

   114

                errmess = ''.join(Pyro.util.getPyroTraceback(e))

   115

                confnodesroot.logger.write_error(errmess + "\n")

   116

                print(errmess)

   117

                confnodesroot._SetConnector(None)

   118

            return default

   119

        return catcher_func

   120

   121

    # Check connection is effective.

   122

    # lambda is for getattr of GetPLCstatus to happen inside catcher

   123

    IDPSK = PyroCatcher(RemotePLCObjectProxy.GetPLCID)()

   124

    if IDPSK is None:

   125

        confnodesroot.logger.write_error(_("Cannot get PLC ID - connection failed.\n"))

   126

        return None

   127

   130

   131

    _special_return_funcs = {

   132

        "StartPLC": False,

   133

        "GetTraceVariables": ("Broken", None),

   134

        "GetPLCstatus": ("Broken", None),

   135

        "RemoteExec": (-1, "RemoteExec script failed!")

   136

    }

   137

   138

    class PyroProxyProxy(object):

   139

        """

   140

        A proxy proxy class to handle Beremiz Pyro interface specific behavior.

   141

        And to put Pyro exception catcher in between caller and Pyro proxy

   142

        """

   144

        def __getattr__(self, attrName):

   145

            member = self.__dict__.get(attrName, None)

   146

            if member is None:

   147

                def my_local_func(*args, **kwargs):

   148

                    return RemotePLCObjectProxy.__getattr__(attrName)(*args, **kwargs)

   149

                member = PyroCatcher(my_local_func, _special_return_funcs.get(attrName, None))

   150

                self.__dict__[attrName] = member

   151

            return member

   152

   153

    return PyroProxyProxy()

   154