text: #
  # This file is part of pysnmp software.
  #
  # Copyright (c) 2005-2018, Ilya Etingof <etingof@gmail.com>
  # License: http://snmplabs.com/pysnmp/license.html
  #
  import socket
  import sys
  from pysnmp.carrier.asyncore.dgram import udp, udp6
  from pysnmp.hlapi.transport import AbstractTransportTarget
  from pysnmp import error
  
  __all__ = ['Udp6TransportTarget', 'UdpTransportTarget']
  
  
  class UdpTransportTarget(AbstractTransportTarget):
      """Creates UDP/IPv4 configuration entry and initialize socket API if needed.
  
      This object can be used for adding new entries to Local Configuration
      Datastore (LCD) managed by :py:class:`~pysnmp.hlapi.SnmpEngine`
      class instance.
  
      See :RFC:`1906#section-3` for more information on the UDP transport mapping.
  
      Parameters
      ----------
      transportAddr: :py:class:`tuple`
          Indicates remote address in Python :py:mod:`socket` module format
          which is a tuple of FQDN, port where FQDN is a string representing
          either hostname or IPv4 address in quad-dotted form, port is an
          integer.
      timeout: :py:class:`int`
          Response timeout in seconds.
      retries: :py:class:`int`
          Maximum number of request retries, 0 retries means just a single
          request.
      tagList: :py:class:`str`
          Arbitrary string that contains a list of space-separated tag
          strings used to select target addresses and/or SNMP configuration
          (see :RFC:`3413#section-4.1.1`, :RFC:`2576#section-5.3` and
          :py:class:`~pysnmp.hlapi.CommunityData` object).
  
      Examples
      --------
      >>> from pysnmp.hlapi.asyncore import UdpTransportTarget
      >>> UdpTransportTarget(('demo.snmplabs.com', 161))
      UdpTransportTarget(('195.218.195.228', 161), timeout=1, retries=5, tagList='')
      >>>
  
      """
      transportDomain = udp.domainName
      protoTransport = udp.UdpSocketTransport
  
      def _resolveAddr(self, transportAddr):
          try:
              return socket.getaddrinfo(transportAddr[0],
                                        transportAddr[1],
                                        socket.AF_INET,
                                        socket.SOCK_DGRAM,
                                        socket.IPPROTO_UDP)[0][4][:2]
          except socket.gaierror:
              raise error.PySnmpError('Bad IPv4/UDP transport address %s: %s' % (
                  '@'.join([str(x) for x in transportAddr]), sys.exc_info()[1]))
  
  
  class Udp6TransportTarget(AbstractTransportTarget):
      """Creates UDP/IPv6 configuration entry and initialize socket API if needed.
  
      This object can be used for adding new entries to Local Configuration
      Datastore (LCD) managed by :py:class:`~pysnmp.hlapi.SnmpEngine`
      class instance.
  
      See :RFC:`1906#section-3`, :RFC:`2851#section-4` for more information
      on the UDP and IPv6 transport mapping.
  
      Parameters
      ----------
      transportAddr : tuple
          Indicates remote address in Python :py:mod:`socket` module format
          which is a tuple of FQDN, port where FQDN is a string representing
          either hostname or IPv6 address in one of three conventional forms
          (:RFC:`1924#section-3`), port is an integer.
      timeout : int
          Response timeout in seconds.
      retries : int
          Maximum number of request retries, 0 retries means just a single
          request.
      tagList : str
          Arbitrary string that contains a list of tag values which are used
          to select target addresses for a particular operation
          (:RFC:`3413#section-4.1.4`).
  
      Examples
      --------
      >>> from pysnmp.hlapi.asyncore import Udp6TransportTarget
      >>> Udp6TransportTarget(('google.com', 161))
      Udp6TransportTarget(('2a00:1450:4014:80a::100e', 161), timeout=1, retries=5, tagList='')
      >>> Udp6TransportTarget(('FEDC:BA98:7654:3210:FEDC:BA98:7654:3210', 161))
      Udp6TransportTarget(('fedc:ba98:7654:3210:fedc:ba98:7654:3210', 161), timeout=1, retries=5, tagList='')
      >>> Udp6TransportTarget(('1080:0:0:0:8:800:200C:417A', 161))
      Udp6TransportTarget(('1080::8:800:200c:417a', 161), timeout=1, retries=5, tagList='')
      >>> Udp6TransportTarget(('::0', 161))
      Udp6TransportTarget(('::', 161), timeout=1, retries=5, tagList='')
      >>> Udp6TransportTarget(('::', 161))
      Udp6TransportTarget(('::', 161), timeout=1, retries=5, tagList='')
      >>>
  
      """
      transportDomain = udp6.domainName
      protoTransport = udp6.Udp6SocketTransport
  
      def _resolveAddr(self, transportAddr):
          try:
              return socket.getaddrinfo(transportAddr[0],
                                        transportAddr[1],
                                        socket.AF_INET6,
                                        socket.SOCK_DGRAM,
                                        socket.IPPROTO_UDP)[0][4][:2]
          except socket.gaierror:
              raise error.PySnmpError('Bad IPv6/UDP transport address %s: %s' % (
                  '@'.join([str(x) for x in transportAddr]), sys.exc_info()[1]))
  