Python socket.getaddrinfo() Examples

def setup_conn(port, accept_handler):
    global listen_s
    listen_s = socket.socket()
    listen_s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    ai = socket.getaddrinfo("0.0.0.0", port)
    addr = ai[0][4]

    listen_s.bind(addr)
    listen_s.listen(1)
    if accept_handler:
        listen_s.setsockopt(socket.SOL_SOCKET, 20, accept_handler)
    for i in (network.AP_IF, network.STA_IF):
        iface = network.WLAN(i)
        if iface.active():
            print("WebREPL daemon started on ws://%s:%d" % (iface.ifconfig()[0], port))
    return listen_s 

def __init__(self, host, port = POP3_SSL_PORT, keyfile = None, certfile = None):
            self.host = host
            self.port = port
            self.keyfile = keyfile
            self.certfile = certfile
            self.buffer = ""
            msg = "getaddrinfo returns an empty list"
            self.sock = None
            for res in socket.getaddrinfo(self.host, self.port, 0, socket.SOCK_STREAM):
                af, socktype, proto, canonname, sa = res
                try:
                    self.sock = socket.socket(af, socktype, proto)
                    self.sock.connect(sa)
                except socket.error, msg:
                    if self.sock:
                        self.sock.close()
                    self.sock = None
                    continue
                break 

def select_ip_version(host, port):
    """Returns AF_INET4 or AF_INET6 depending on where to connect to."""
    # disabled due to problems with current ipv6 implementations
    # and various operating systems.  Probably this code also is
    # not supposed to work, but I can't come up with any other
    # ways to implement this.
    # try:
    #     info = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
    #                               socket.SOCK_STREAM, 0,
    #                               socket.AI_PASSIVE)
    #     if info:
    #         return info[0][0]
    # except socket.gaierror:
    #     pass
    if ':' in host and hasattr(socket, 'AF_INET6'):
        return socket.AF_INET6
    return socket.AF_INET 

def select_ip_version(host, port):
    """Returns AF_INET4 or AF_INET6 depending on where to connect to."""
    # disabled due to problems with current ipv6 implementations
    # and various operating systems.  Probably this code also is
    # not supposed to work, but I can't come up with any other
    # ways to implement this.
    # try:
    #     info = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
    #                               socket.SOCK_STREAM, 0,
    #                               socket.AI_PASSIVE)
    #     if info:
    #         return info[0][0]
    # except socket.gaierror:
    #     pass
    if ':' in host and hasattr(socket, 'AF_INET6'):
        return socket.AF_INET6
    return socket.AF_INET 

def _convert_host_to_ip(host):
    """
    Perform forward DNS resolution on host, IP will give the same IP

    Args:
        host: String with either hostname, IPv4, or IPv6 address

    Returns:
        List of tuples containing address family and IP
    """
    addrinfo = socket.getaddrinfo(host, 80, 0, 0, socket.SOL_TCP)
    ips = []
    for family, socktype, proto, canonname, sockaddr in addrinfo:
        ip = sockaddr[0]
        ips.append((family, ip))
        if family == socket.AF_INET:
            ips.append((socket.AF_INET6, "::ffff:" + ip))
    return ips 

def select_ip_version(host, port):
    """Returns AF_INET4 or AF_INET6 depending on where to connect to."""
    # disabled due to problems with current ipv6 implementations
    # and various operating systems.  Probably this code also is
    # not supposed to work, but I can't come up with any other
    # ways to implement this.
    # try:
    #     info = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
    #                               socket.SOCK_STREAM, 0,
    #                               socket.AI_PASSIVE)
    #     if info:
    #         return info[0][0]
    # except socket.gaierror:
    #     pass
    if ':' in host and hasattr(socket, 'AF_INET6'):
        return socket.AF_INET6
    return socket.AF_INET 

def setup_conn(port, accept_handler):
    global listen_s
    listen_s = socket.socket()
    listen_s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    ai = socket.getaddrinfo("0.0.0.0", port)
    addr = ai[0][4]

    listen_s.bind(addr)
    listen_s.listen(1)
    if accept_handler:
        listen_s.setsockopt(socket.SOL_SOCKET, 20, accept_handler)
    for i in (network.AP_IF, network.STA_IF):
        iface = network.WLAN(i)
        if iface.active():
            print("WebREPL daemon started on ws://%s:%d" % (iface.ifconfig()[0], port))
    return listen_s 

def __init__(self, hosts):
        """
        The `hosts` parameter should be a sequence of hosts to permit
        connections to.
        """
        msg = ('WhiteListRoundRobinPolicy is deprecated. '
               'It will be removed in 4.0. '
               'It can effectively be reimplemented using HostFilterPolicy.')
        warn(msg, DeprecationWarning)
        # DeprecationWarnings are silent by default so we also log the message
        log.warning(msg)

        self._allowed_hosts = hosts
        self._allowed_hosts_resolved = [endpoint[4][0] for a in self._allowed_hosts
                                        for endpoint in socket.getaddrinfo(a, None, socket.AF_UNSPEC, socket.SOCK_STREAM)]

        RoundRobinPolicy.__init__(self) 

def host_is_local(hostname, port=22): # no port specified, just use the ssh port
    """
    Returns True if the hostname points to the localhost, otherwise False.
    """
    hostname = socket.getfqdn(hostname)
    if hostname in ("localhost", "0.0.0.0", "127.0.0.1", "1.0.0.127.in-addr.arpa",
                    "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa"):
        return True
    localhost = socket.gethostname()
    if hostname == localhost:
        return True
    localaddrs = socket.getaddrinfo(localhost, port)
    targetaddrs = socket.getaddrinfo(hostname, port)
    for (ignored_family, ignored_socktype, ignored_proto, ignored_canonname,
         sockaddr) in localaddrs:
        for (ignored_rfamily, ignored_rsocktype, ignored_rproto,
             ignored_rcanonname, rsockaddr) in targetaddrs:
            if rsockaddr[0] == sockaddr[0]:
                return True
    return False 

def _socket_bind_addr(self, sock, af):
        bind_addr = ''
        if self._bind and af == socket.AF_INET:
            bind_addr = self._bind
        elif self._bindv6 and af == socket.AF_INET6:
            bind_addr = self._bindv6

        bind_addr = bind_addr.replace("::ffff:", "")
        if bind_addr in self._ignore_bind_list:
            bind_addr = None
        if bind_addr:
            local_addrs = socket.getaddrinfo(bind_addr, 0, 0, socket.SOCK_DGRAM, socket.SOL_UDP)
            if local_addrs[0][0] == af:
                logging.debug("bind %s" % (bind_addr,))
                try:
                    sock.bind((bind_addr, 0))
                except Exception as e:
                    logging.warn("bind %s fail" % (bind_addr,)) 

def _socket_bind_addr(self, sock, af):
        bind_addr = ''
        if self._bind and af == socket.AF_INET:
            bind_addr = self._bind
        elif self._bindv6 and af == socket.AF_INET6:
            bind_addr = self._bindv6
        else:
            bind_addr = self._accept_address[0]

        bind_addr = bind_addr.replace("::ffff:", "")
        if bind_addr in self._ignore_bind_list:
            bind_addr = None
        if bind_addr:
            local_addrs = socket.getaddrinfo(bind_addr, 0, 0, socket.SOCK_STREAM, socket.SOL_TCP)
            if local_addrs[0][0] == af:
                logging.debug("bind %s" % (bind_addr,))
                try:
                    sock.bind((bind_addr, 0))
                except Exception as e:
                    logging.warn("bind %s fail" % (bind_addr,)) 

def create_socket_ipv6_rx_ucast(self):
        if self._local_ipv6_address is None:
            self.warning("Could not create IPv6 UDP socket: don't have a local address")
            return None
        try:
            sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
        except (IOError, OSError) as err:
            self.warning("Could not create IPv6 UDP socket: %s", err)
            return None
        self.enable_addr_and_port_reuse(sock)
        try:
            sockaddr = socket.getaddrinfo(self._local_ipv6_address,
                                          self._local_port,
                                          socket.AF_INET6,
                                          socket.SOCK_DGRAM)[0][4]
            sock.bind(sockaddr)
        except (IOError, OSError) as err:
            self.warning("Could not bind IPv6 UDP socket to address %s port %d: %s",
                         self._local_ipv6_address, self._local_port, err)
            return None
        return sock 

def create_socket_ipv6_tx_ucast(self, remote_address, port):
        try:
            sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
        except IOError as err:
            self.warning("Could not create IPv6 UDP socket: %s", err)
            return None
        self.enable_addr_and_port_reuse(sock)
        try:
            sock_addr = socket.getaddrinfo(remote_address, port, socket.AF_INET6,
                                           socket.SOCK_DGRAM)[0][4]
            sock.connect(sock_addr)
        except IOError as err:
            self.warning("Could not connect UDP socket to address %s port %d: %s",
                         remote_address, port, err)
            return None
        return sock 

def _create_remote_socket(self, ip, port):
        addrs = socket.getaddrinfo(ip, port, 0, socket.SOCK_STREAM, socket.SOL_TCP)
        if len(addrs) == 0:
            raise Exception("getaddrinfo failed for %s:%d" % (ip, port))
        af, socktype, proto, canonname, sa = addrs[0]
        if self._forbidden_iplist:
            if common.to_str(sa[0]) in self._forbidden_iplist:
                raise Exception('IP %s is in forbidden list, reject' %
                                common.to_str(sa[0]))
        remote_sock = socket.socket(af, socktype, proto)
        self._remote_sock = remote_sock

        self._fd_to_handlers[remote_sock.fileno()] = self

        remote_sock.setblocking(False)
        remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
        return remote_sock 

def is_valid_ip(ip):
    """Returns true if the given string is a well-formed IP address.

    Supports IPv4 and IPv6.
    """
    if not ip or '\x00' in ip:
        # getaddrinfo resolves empty strings to localhost, and truncates
        # on zero bytes.
        return False
    try:
        res = socket.getaddrinfo(ip, 0, socket.AF_UNSPEC,
                                 socket.SOCK_STREAM,
                                 0, socket.AI_NUMERICHOST)
        return bool(res)
    except socket.gaierror as e:
        if e.args[0] == socket.EAI_NONAME:
            return False
        raise
    return True 

def makeport(self):
        '''Create a new socket and send a PORT command for it.'''
        err = None
        sock = None
        for res in socket.getaddrinfo(None, 0, self.af, socket.SOCK_STREAM, 0, socket.AI_PASSIVE):
            af, socktype, proto, canonname, sa = res
            try:
                sock = socket.socket(af, socktype, proto)
                sock.bind(sa)
            except socket.error, err:
                if sock:
                    sock.close()
                sock = None
                continue
            break 

def test_create_connection(self):
        # Issue #9792: errors raised by create_connection() should have
        # a proper errno attribute.
        port = test_support.find_unused_port()
        with self.assertRaises(socket.error) as cm:
            socket.create_connection((HOST, port))

        # Issue #16257: create_connection() calls getaddrinfo() against
        # 'localhost'.  This may result in an IPV6 addr being returned
        # as well as an IPV4 one:
        #   >>> socket.getaddrinfo('localhost', port, 0, SOCK_STREAM)
        #   >>> [(2,  2, 0, '', ('127.0.0.1', 41230)),
        #        (26, 2, 0, '', ('::1', 41230, 0, 0))]
        #
        # create_connection() enumerates through all the addresses returned
        # and if it doesn't successfully bind to any of them, it propagates
        # the last exception it encountered.
        #
        # On Solaris, ENETUNREACH is returned in this circumstance instead
        # of ECONNREFUSED.  So, if that errno exists, add it to our list of
        # expected errnos.
        expected_errnos = [ errno.ECONNREFUSED, ]
        if hasattr(errno, 'ENETUNREACH'):
            expected_errnos.append(errno.ENETUNREACH)

        self.assertIn(cm.exception.errno, expected_errnos) 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def time():
    NTP_QUERY = bytearray(48)
    NTP_QUERY[0] = 0x1b
    addr = socket.getaddrinfo(host, 123)[0][-1]
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.settimeout(1)
    res = s.sendto(NTP_QUERY, addr)
    msg = s.recv(48)
    s.close()
    val = struct.unpack("!I", msg[40:44])[0]
    return val - NTP_DELTA

# There's currently no timezone support in MicroPython, so
# utime.localtime() will return UTC time (as if it was .gmtime()) 

def time():
    NTP_QUERY = bytearray(48)
    NTP_QUERY[0] = 0x1b
    addr = socket.getaddrinfo(host, 123)[0][-1]
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.settimeout(1)
    res = s.sendto(NTP_QUERY, addr)
    msg = s.recv(48)
    s.close()
    val = struct.unpack("!I", msg[40:44])[0]
    return val - NTP_DELTA

# There's currently no timezone support in MicroPython, so
# utime.localtime() will return UTC time (as if it was .gmtime()) 

def _xmit_packet(self, retry=True, delay_xmit=None):
        if self.sequencenumber:
            self.sequencenumber += 1
        if delay_xmit is not None:
            # skip transmit, let retry timer do it's thing
            self.waiting_sessions[self] = {}
            self.waiting_sessions[self]['ipmisession'] = self
            self.waiting_sessions[self]['timeout'] = delay_xmit +  _monotonic_time()
            return  
        if self.sockaddr:
            self.send_data(self.netpacket, self.sockaddr)
        else:
            self.allsockaddrs = []
            try:
                for res in socket.getaddrinfo(self.bmc, self.port, 0, socket.SOCK_DGRAM):
                    sockaddr = res[4]
                    if res[0] == socket.AF_INET:
                        # convert the sockaddr to AF_INET6
                        newhost = '::ffff:' + sockaddr[0]
                        sockaddr = (newhost, sockaddr[1], 0, 0)
                    self.allsockaddrs.append(sockaddr)
                    self.bmc_handlers[sockaddr] = self
                    self.send_data(self.netpacket, sockaddr)
            except socket.gaierror:
                raise exc.IpmiException("Unable to transmit to specified address")
        if retry:
            self.waiting_sessions[self] = {}
            self.waiting_sessions[self]['ipmisession'] = self
            self.waiting_sessions[self]['timeout'] = self.timeout + _monotonic_time() 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def translate(self, addr):
        """
        Reverse DNS the public broadcast_address, then lookup that hostname to get the AWS-resolved IP, which
        will point to the private IP address within the same datacenter.
        """
        # get family of this address so we translate to the same
        family = socket.getaddrinfo(addr, 0, socket.AF_UNSPEC, socket.SOCK_STREAM)[0][0]
        host = socket.getfqdn(addr)
        for a in socket.getaddrinfo(host, 0, family, socket.SOCK_STREAM):
            try:
                return a[4][0]
            except Exception:
                pass
        return addr 

def _connect_socket(self):
        sockerr = None
        addresses = socket.getaddrinfo(self.host, self.port, socket.AF_UNSPEC, socket.SOCK_STREAM)
        if not addresses:
            raise ConnectionException("getaddrinfo returned empty list for %s" % (self.host,))
        for (af, socktype, proto, canonname, sockaddr) in addresses:
            try:
                self._socket = self._socket_impl.socket(af, socktype, proto)
                if self.ssl_options:
                    if not self._ssl_impl:
                        raise RuntimeError("This version of Python was not compiled with SSL support")
                    self._socket = self._ssl_impl.wrap_socket(self._socket, **self.ssl_options)
                self._socket.settimeout(self.connect_timeout)
                self._socket.connect(sockaddr)
                self._socket.settimeout(None)
                if self._check_hostname:
                    ssl.match_hostname(self._socket.getpeercert(), self.host)
                sockerr = None
                break
            except socket.error as err:
                if self._socket:
                    self._socket.close()
                    self._socket = None
                sockerr = err

        if sockerr:
            raise socket.error(sockerr.errno, "Tried connecting to %s. Last error: %s" % ([a[4] for a in addresses], sockerr.strerror or sockerr))

        if self.sockopts:
            for args in self.sockopts:
                self._socket.setsockopt(*args) 

def test_error_multiple(self):
        if len(socket.getaddrinfo('localhost', 9043, socket.AF_UNSPEC, socket.SOCK_STREAM)) < 2:
            raise unittest.SkipTest('localhost only resolves one address')
        cluster = Cluster(connection_class=self.connection_class, contact_points=['localhost'], port=9043,
                          connect_timeout=10, protocol_version=PROTOCOL_VERSION)
        self.assertRaisesRegexp(NoHostAvailable, '\(\'Unable to connect.*Tried connecting to \[\(.*\(.*\].*Last error',
                                cluster.connect) 

def getdestbyaddr(self, address, af):
        #print('getaddrinfo', address[0], address[1], af, self.sock_type)
        if af == AF_INET6 and address[0].startswith('['):
            return address
        ainfo = getaddrinfo(address[0], address[1], af, self.sock_type)
        amatch = [x[4] for x in ainfo if x[0] == af]
        if len(amatch) == 0:
            raise Exception('no match for the %s in AF %s' % (address, af))
        amatch = amatch[0]
        if af == AF_INET6:
            return (('[%s]' % amatch[0], amatch[1]))
        return ((amatch[0], amatch[1])) 

def run(self):
        while True:
            self.userv.wi_available.acquire()
            while len(self.userv.wi) == 0:
                self.userv.wi_available.wait()
            wi = self.userv.wi.pop(0)
            if wi == None:
                # Shutdown request, relay it further
                self.userv.wi.append(None)
                self.userv.wi_available.notify()
            self.userv.wi_available.release()
            if wi == None:
                break
            data, address = wi
            try:
                ai = socket.getaddrinfo(address[0], None, self.userv.uopts.family)
            except:
                continue
            if self.userv.uopts.family == socket.AF_INET:
                address = (ai[0][4][0], address[1])
            else:
                address = (ai[0][4][0], address[1], ai[0][4][2], ai[0][4][3])
            for i in range(0, 20):
                try:
                    if self.userv.skt.sendto(data, address) == len(data):
                        break
                except socket.error as why:
                    if isinstance(why, BrokenPipeError):
                        self.userv = None
                        return
                    if why.errno not in (EWOULDBLOCK, ENOBUFS, EAGAIN):
                        break
                sleep(0.01)
        self.userv = None 

def __init__(self, global_config, uopts):
        self.uopts = uopts.getCopy()
        self.skt = socket.socket(self.uopts.family, socket.SOCK_DGRAM)
        if self.uopts.laddress != None:
            ai = socket.getaddrinfo(self.uopts.laddress[0], None, self.uopts.family)
            if self.uopts.family == socket.AF_INET:
                address = (ai[0][4][0], self.uopts.laddress[1])
            else:
                address = (ai[0][4][0], self.uopts.laddress[1], ai[0][4][2], ai[0][4][3])
            if (self.uopts.flags & socket.SO_REUSEADDR) != 0:
                self.skt.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
            if hasattr(socket, 'SO_REUSEPORT') and \
              (self.uopts.flags & socket.SO_REUSEPORT) != 0:
                self.skt.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
            self.skt.bind(address)
            if self.uopts.laddress[1] == 0:
                self.uopts.laddress = self.skt.getsockname()
        self.sendqueue = []
        self.stats = [0, 0, 0]
        self.wi_available = Condition()
        self.wi = []
        self.asenders = []
        self.areceivers = []
        if self.uopts.nworkers == None:
            nworkers = _DEFAULT_NWORKERS
        else:
            nworkers = self.uopts.nworkers
        for i in range(0, nworkers):
            self.asenders.append(AsyncSender(self))
            self.areceivers.append(AsyncReceiver(self)) 

def local4remote(lookup_address, family = socket.AF_INET):
    skt = socket.socket(family, socket.SOCK_DGRAM)
    ai = socket.getaddrinfo(lookup_address, None, family)
    if family == socket.AF_INET:
        _address = (ai[0][4][0], 12345)
    else:
        _address = (ai[0][4][0], 12345, ai[0][4][2], ai[0][4][3])
    skt.connect(_address)
    if family == socket.AF_INET:
        laddress = skt.getsockname()[0]
    else:
        laddress = '[%s]' % skt.getsockname()[0]
    return laddress 

def _is_gce_instance() -> bool:
    try:
        socket.getaddrinfo("metadata.google.internal", 80)
    except socket.gaierror:
        return False
    return True 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def create_connection(address, timeout=_GLOBAL_DEFAULT_TIMEOUT,
                      source_address=None):
    """Backport of 3-argument create_connection() for Py2.6.

    Connect to *address* and return the socket object.

    Convenience function.  Connect to *address* (a 2-tuple ``(host,
    port)``) and return the socket object.  Passing the optional
    *timeout* parameter will set the timeout on the socket instance
    before attempting to connect.  If no *timeout* is supplied, the
    global default timeout setting returned by :func:`getdefaulttimeout`
    is used.  If *source_address* is set it must be a tuple of (host, port)
    for the socket to bind as a source address before making the connection.
    An host of '' or port 0 tells the OS to use the default.
    """

    host, port = address
    err = None
    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
        af, socktype, proto, canonname, sa = res
        sock = None
        try:
            sock = socket(af, socktype, proto)
            if timeout is not _GLOBAL_DEFAULT_TIMEOUT:
                sock.settimeout(timeout)
            if source_address:
                sock.bind(source_address)
            sock.connect(sa)
            return sock

        except error as _:
            err = _
            if sock is not None:
                sock.close()

    if err is not None:
        raise err
    else:
        raise error("getaddrinfo returns an empty list")

# Backport from Py2.7 for Py2.6: 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def find_free_address():
    """Bind to None, 0 to find an unused port on localhost (IPv4 or IPv6)

    :return:
    """
    err = None
    for info in socket.getaddrinfo(None, 0, socket.AF_UNSPEC,
                                   socket.SOCK_STREAM):
        family, stype, proto, _, addr = info
        sock = None
        try:
            sock = socket.socket(family, stype, proto)
            sock.bind(addr)
            if family == socket.AF_INET:
                return "{}:{}".format(*sock.getsockname())
            elif family == socket.AF_INET6:
                return "[{}]:{}".format(*sock.getsockname()[:2])
        except socket.error as e:
            err = e
        finally:
            if sock is not None:
                sock.close()
    if err is not None:
        raise err  # pylint: disable=raising-bad-type
    else:
        raise socket.error("getaddrinfo returns an empty list") 

def _handle_server_dns_resolved(self, error, remote_addr, server_addr, data):
        if error:
            return
        try:
            addrs = socket.getaddrinfo(server_addr, remote_addr[1], 0, socket.SOCK_DGRAM, socket.SOL_UDP)
            if not addrs: # drop
                return
            af, socktype, proto, canonname, sa = addrs[0]
            if af == socket.AF_INET6:
                self._remote_sock_v6.sendto(data, (server_addr, remote_addr[1]))
                if self._udpv6_send_pack_id == 0:
                    addr, port = self._remote_sock_v6.getsockname()[:2]
                    common.connect_log('UDPv6 sendto %s(%s):%d from %s:%d by user %d' %
                        (common.to_str(remote_addr[0]), common.to_str(server_addr), remote_addr[1], addr, port, self._user_id))
                self._udpv6_send_pack_id += 1
            else:
                self._remote_sock.sendto(data, (server_addr, remote_addr[1]))
                if self._udp_send_pack_id == 0:
                    addr, port = self._remote_sock.getsockname()[:2]
                    common.connect_log('UDP sendto %s(%s):%d from %s:%d by user %d' %
                        (common.to_str(remote_addr[0]), common.to_str(server_addr), remote_addr[1], addr, port, self._user_id))
                self._udp_send_pack_id += 1
            return True
        except Exception as e:
            shell.print_exception(e)
            logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) 

def findipv4(fqdn):
	'''
		find IPv4 address of fqdn
	'''
	import socket
	ipv4 = socket.getaddrinfo(fqdn, 80, socket.AF_INET)[0][4][0]
	return ipv4 

def findipv6(fqdn):
	'''
		find IPv6 address of fqdn
	'''
	import socket
	ipv6 = socket.getaddrinfo(fqdn, 80, socket.AF_INET6)[0][4][0]
	return ipv6 

def create_connection(address, timeout=_GLOBAL_DEFAULT_TIMEOUT,
                      source_address=None):
    """Connect to *address* and return the socket object.

    Convenience function.  Connect to *address* (a 2-tuple ``(host,
    port)``) and return the socket object.  Passing the optional
    *timeout* parameter will set the timeout on the socket instance
    before attempting to connect.  If no *timeout* is supplied, the
    global default timeout setting returned by :func:`getdefaulttimeout`
    is used.  If *source_address* is set it must be a tuple of (host, port)
    for the socket to bind as a source address before making the connection.
    An host of '' or port 0 tells the OS to use the default.

    Largely vendored from Python 2.7, modified to work with Python 2.4
    """

    host, port = address
    err = None
    for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
        af, socktype, proto, canonname, sa = res
        sock = None
        try:
            sock = socket.socket(af, socktype, proto)
            if timeout is not _GLOBAL_DEFAULT_TIMEOUT:
                sock.settimeout(float(timeout))
            if source_address:
                sock.bind(source_address)
            sock.connect(sa)
            return sock

        except socket.error:
            err = get_exception()
            if sock is not None:
                sock.close()

    if err is not None:
        raise err
    else:
        raise socket.error("getaddrinfo returns an empty list") 

def create_socket_ipv6_tx_mcast(self, multicast_address, port, loopback):
        if self._interface_index is None:
            self.warning("Could not create IPv6 multicast TX socket: unknown interface index")
            return None
        try:
            sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
        except IOError as err:
            self.warning("Could not create IPv6 UDP socket: %s", err)
            return None
        self.enable_addr_and_port_reuse(sock)
        try:
            sock.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_MULTICAST_IF, self._interface_index)
        except IOError as err:
            self.warning("Could not set IPv6 multicast interface index %d: %s",
                         self._interface_index, err)
            return None
        try:
            loop_value = 1 if loopback else 0
            sock.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_MULTICAST_LOOP, loop_value)
        except IOError as err:
            self.warning("Could not set IPv6 multicast loopback value %d: %s", loop_value, err)
            return None
        try:
            scoped_ipv6_multicast_address = (
                str(multicast_address) + '%' + self.physical_interface_name)
            sock_addr = socket.getaddrinfo(scoped_ipv6_multicast_address, port,
                                           socket.AF_INET6, socket.SOCK_DGRAM)[0][4]
            sock.connect(sock_addr)
        except (IOError, OSError) as err:
            self.warning("Could not connect UDP socket to address %s port %d: %s",
                         scoped_ipv6_multicast_address, port, err)
            return None
        return sock 

def _get_redirect_host(self, client_address, ogn_data):
        # test
        host_list = [(b"www.bing.com", 80), (b"www.microsoft.com", 80), (b"cloudfront.com", 80), (b"cloudflare.com", 80), (b"1.2.3.4", 1000), (b"0.0.0.0", 0)]
        hash_code = binascii.crc32(ogn_data)
        addrs = socket.getaddrinfo(client_address[0], client_address[1], 0, socket.SOCK_STREAM, socket.SOL_TCP)
        af, socktype, proto, canonname, sa = addrs[0]
        address_bytes = common.inet_pton(af, sa[0])
        if len(address_bytes) == 16:
            addr = struct.unpack('>Q', address_bytes[8:])[0]
        if len(address_bytes) == 4:
            addr = struct.unpack('>I', address_bytes)[0]
        else:
            addr = 0
        return host_list[((hash_code & 0xffffffff) + addr + 3) % len(host_list)] 

def _create_remote_socket(self, ip, port):
        if self._remote_udp:
            addrs_v6 = socket.getaddrinfo("::", 0, 0, socket.SOCK_DGRAM, socket.SOL_UDP)
            addrs = socket.getaddrinfo("0.0.0.0", 0, 0, socket.SOCK_DGRAM, socket.SOL_UDP)
        else:
            addrs = socket.getaddrinfo(ip, port, 0, socket.SOCK_STREAM, socket.SOL_TCP)
        if len(addrs) == 0:
            raise Exception("getaddrinfo failed for %s:%d" % (ip, port))
        af, socktype, proto, canonname, sa = addrs[0]
        if self._forbidden_iplist:
            if common.to_str(sa[0]) in self._forbidden_iplist:
                raise Exception('IP %s is in forbidden list, reject' %
                                common.to_str(sa[0]))
        remote_sock = socket.socket(af, socktype, proto)
        self._remote_sock = remote_sock
        self._fd_to_handlers[remote_sock.fileno()] = self

        if self._remote_udp:
            af, socktype, proto, canonname, sa = addrs_v6[0]
            remote_sock_v6 = socket.socket(af, socktype, proto)
            self._remote_sock_v6 = remote_sock_v6
            self._fd_to_handlers[remote_sock_v6.fileno()] = self
            remote_sock.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 1024 * 32)
            remote_sock.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 1024 * 32)
            remote_sock_v6.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 1024 * 32)
            remote_sock_v6.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 1024 * 32)

        remote_sock.setblocking(False)
        if self._remote_udp:
            remote_sock_v6.setblocking(False)
        else:
            remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
        return remote_sock 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def _write_SOCKS5_address(self, addr, file):
        """
        Return the host and port packed for the SOCKS5 protocol,
        and the resolved address as a tuple object.
        """
        host, port = addr
        proxy_type, _, _, rdns, username, password = self.proxy
        family_to_byte = {socket.AF_INET: b"\x01", socket.AF_INET6: b"\x04"}

        # If the given destination address is an IP address, we'll
        # use the IP address request even if remote resolving was specified.
        # Detect whether the address is IPv4/6 directly.
        for family in (socket.AF_INET, socket.AF_INET6):
            try:
                addr_bytes = socket.inet_pton(family, host)
                file.write(family_to_byte[family] + addr_bytes)
                host = socket.inet_ntop(family, addr_bytes)
                file.write(struct.pack(">H", port))
                return host, port
            except socket.error:
                continue

        # Well it's not an IP number, so it's probably a DNS name.
        if rdns:
            # Resolve remotely
            host_bytes = host.encode('idna')
            file.write(b"\x03" + chr(len(host_bytes)).encode() + host_bytes)
        else:
            # Resolve locally
            addresses = socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM, socket.IPPROTO_TCP, socket.AI_ADDRCONFIG)
            # We can't really work out what IP is reachable, so just pick the
            # first.
            target_addr = addresses[0]
            family = target_addr[0]
            host = target_addr[4][0]

            addr_bytes = socket.inet_pton(family, host)
            file.write(family_to_byte[family] + addr_bytes)
            host = socket.inet_ntop(family, addr_bytes)
        file.write(struct.pack(">H", port))
        return host, port 

def allowed_gai_family():
    """This function is designed to work in the context of
    getaddrinfo, where family=socket.AF_UNSPEC is the default and
    will perform a DNS search for both IPv6 and IPv4 records."""

    family = socket.AF_INET
    if HAS_IPV6:
        family = socket.AF_UNSPEC
    return family 

def connect(self, host=HOST, port=GPSD_PORT):
        """Connect to a host on a given port.
        Arguments:
            host: default host='127.0.0.1'
            port: default port=2947
        """
        for alotta_stuff in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
            family, socktype, proto, _canonname, host_port = alotta_stuff
            try:
                self.streamSock = socket.socket(family, socktype, proto)
                self.streamSock.connect(host_port)
                self.streamSock.setblocking(False)
            except (OSError, IOError) as error:
                sys.stderr.write('\r\nGPSDSocket.connect exception is--> {}'.format(error))
                sys.stderr.write('\r\nGPS3 gpsd connection at \'{0}\' on port \'{1}\' failed\r\n'.format(host, port)) 

def connect(self, host=HOST, port=GPSD_PORT):
        """Connect to a host on a given port.
        Arguments:
            host: default host='127.0.0.1'
            port: default port=2947
        """
        for alotta_stuff in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
            family, socktype, proto, _canonname, host_port = alotta_stuff
            try:
                self.streamSock = socket.socket(family, socktype, proto)
                self.streamSock.connect(host_port)
                self.streamSock.setblocking(False)
            except (OSError, IOError) as error:
                sys.stderr.write(f'\r\nGPSDSocket.connect exception is--> {error}')
                sys.stderr.write(f'\r\nAGPS3 connection to gpsd at \'{host}\' on port \'{port}\' failed\r\n')