Lib/test/test_ftplib.py

"""Test script for ftplib module."""

# Modified by Giampaolo Rodola' to test FTP class, IPv6 and TLS
# environment

import ftplib
import asyncore
import asynchat
import socket
import StringIO
import errno
import os
try:
    import ssl
except ImportError:
    ssl = None

from unittest import TestCase, SkipTest, skipUnless
from test import test_support
from test.test_support import HOST, HOSTv6
threading = test_support.import_module('threading')

TIMEOUT = 3
# the dummy data returned by server over the data channel when
# RETR, LIST and NLST commands are issued
RETR_DATA = 'abcde12345\r\n' * 1000
LIST_DATA = 'foo\r\nbar\r\n'
NLST_DATA = 'foo\r\nbar\r\n'


class DummyDTPHandler(asynchat.async_chat):
    dtp_conn_closed = False

    def __init__(self, conn, baseclass):
        asynchat.async_chat.__init__(self, conn)
        self.baseclass = baseclass
        self.baseclass.last_received_data = ''

    def handle_read(self):
        self.baseclass.last_received_data += self.recv(1024)

    def handle_close(self):
        # XXX: this method can be called many times in a row for a single
        # connection, including in clear-text (non-TLS) mode.
        # (behaviour witnessed with test_data_connection)
        if not self.dtp_conn_closed:
            self.baseclass.push('226 transfer complete')
            self.close()
            self.dtp_conn_closed = True

    def handle_error(self):
        raise


class DummyFTPHandler(asynchat.async_chat):

    dtp_handler = DummyDTPHandler

    def __init__(self, conn):
        asynchat.async_chat.__init__(self, conn)
        self.set_terminator("\r\n")
        self.in_buffer = []
        self.dtp = None
        self.last_received_cmd = None
        self.last_received_data = ''
        self.next_response = ''
        self.rest = None
        self.next_retr_data = RETR_DATA
        self.push('220 welcome')

    def collect_incoming_data(self, data):
        self.in_buffer.append(data)

    def found_terminator(self):
        line = ''.join(self.in_buffer)
        self.in_buffer = []
        if self.next_response:
            self.push(self.next_response)
            self.next_response = ''
        cmd = line.split(' ')[0].lower()
        self.last_received_cmd = cmd
        space = line.find(' ')
        if space != -1:
            arg = line[space + 1:]
        else:
            arg = ""
        if hasattr(self, 'cmd_' + cmd):
            method = getattr(self, 'cmd_' + cmd)
            method(arg)
        else:
            self.push('550 command "%s" not understood.' %cmd)

    def handle_error(self):
        raise

    def push(self, data):
        asynchat.async_chat.push(self, data + '\r\n')

    def cmd_port(self, arg):
        addr = map(int, arg.split(','))
        ip = '%d.%d.%d.%d' %tuple(addr[:4])
        port = (addr[4] * 256) + addr[5]
        s = socket.create_connection((ip, port), timeout=10)
        self.dtp = self.dtp_handler(s, baseclass=self)
        self.push('200 active data connection established')

    def cmd_pasv(self, arg):
        sock = socket.socket()
        sock.bind((self.socket.getsockname()[0], 0))
        sock.listen(5)
        sock.settimeout(10)
        ip, port = sock.getsockname()[:2]
        ip = ip.replace('.', ',')
        p1, p2 = divmod(port, 256)
        self.push('227 entering passive mode (%s,%d,%d)' %(ip, p1, p2))
        conn, addr = sock.accept()
        self.dtp = self.dtp_handler(conn, baseclass=self)

    def cmd_eprt(self, arg):
        af, ip, port = arg.split(arg[0])[1:-1]
        port = int(port)
        s = socket.create_connection((ip, port), timeout=10)
        self.dtp = self.dtp_handler(s, baseclass=self)
        self.push('200 active data connection established')

    def cmd_epsv(self, arg):
        sock = socket.socket(socket.AF_INET6)
        sock.bind((self.socket.getsockname()[0], 0))
        sock.listen(5)
        sock.settimeout(10)
        port = sock.getsockname()[1]
        self.push('229 entering extended passive mode (|||%d|)' %port)
        conn, addr = sock.accept()
        self.dtp = self.dtp_handler(conn, baseclass=self)

    def cmd_echo(self, arg):
        # sends back the received string (used by the test suite)
        self.push(arg)

    def cmd_user(self, arg):
        self.push('331 username ok')

    def cmd_pass(self, arg):
        self.push('230 password ok')

    def cmd_acct(self, arg):
        self.push('230 acct ok')

    def cmd_rnfr(self, arg):
        self.push('350 rnfr ok')

    def cmd_rnto(self, arg):
        self.push('250 rnto ok')

    def cmd_dele(self, arg):
        self.push('250 dele ok')

    def cmd_cwd(self, arg):
        self.push('250 cwd ok')

    def cmd_size(self, arg):
        self.push('250 1000')

    def cmd_mkd(self, arg):
        self.push('257 "%s"' %arg)

    def cmd_rmd(self, arg):
        self.push('250 rmd ok')

    def cmd_pwd(self, arg):
        self.push('257 "pwd ok"')

    def cmd_type(self, arg):
        self.push('200 type ok')

    def cmd_quit(self, arg):
        self.push('221 quit ok')
        self.close()

    def cmd_stor(self, arg):
        self.push('125 stor ok')

    def cmd_rest(self, arg):
        self.rest = arg
        self.push('350 rest ok')

    def cmd_retr(self, arg):
        self.push('125 retr ok')
        if self.rest is not None:
            offset = int(self.rest)
        else:
            offset = 0
        self.dtp.push(self.next_retr_data[offset:])
        self.dtp.close_when_done()
        self.rest = None

    def cmd_list(self, arg):
        self.push('125 list ok')
        self.dtp.push(LIST_DATA)
        self.dtp.close_when_done()

    def cmd_nlst(self, arg):
        self.push('125 nlst ok')
        self.dtp.push(NLST_DATA)
        self.dtp.close_when_done()

    def cmd_setlongretr(self, arg):
        # For testing. Next RETR will return long line.
        self.next_retr_data = 'x' * int(arg)
        self.push('125 setlongretr ok')


class DummyFTPServer(asyncore.dispatcher, threading.Thread):

    handler = DummyFTPHandler

    def __init__(self, address, af=socket.AF_INET):
        threading.Thread.__init__(self)
        asyncore.dispatcher.__init__(self)
        self.create_socket(af, socket.SOCK_STREAM)
        self.bind(address)
        self.listen(5)
        self.active = False
        self.active_lock = threading.Lock()
        self.host, self.port = self.socket.getsockname()[:2]
        self.handler_instance = None

    def start(self):
        assert not self.active
        self.__flag = threading.Event()
        threading.Thread.start(self)
        self.__flag.wait()

    def run(self):
        self.active = True
        self.__flag.set()
        while self.active and asyncore.socket_map:
            self.active_lock.acquire()
            asyncore.loop(timeout=0.1, count=1)
            self.active_lock.release()
        asyncore.close_all(ignore_all=True)

    def stop(self):
        assert self.active
        self.active = False
        self.join()

    def handle_accept(self):
        conn, addr = self.accept()
        self.handler_instance = self.handler(conn)

    def handle_connect(self):
        self.close()
    handle_read = handle_connect

    def writable(self):
        return 0

    def handle_error(self):
        raise


if ssl is not None:

    CERTFILE = os.path.join(os.path.dirname(__file__), "keycert3.pem")
    CAFILE = os.path.join(os.path.dirname(__file__), "pycacert.pem")

    class SSLConnection(object, asyncore.dispatcher):
        """An asyncore.dispatcher subclass supporting TLS/SSL."""

        _ssl_accepting = False
        _ssl_closing = False

        def secure_connection(self):
            socket = ssl.wrap_socket(self.socket, suppress_ragged_eofs=False,
                                     certfile=CERTFILE, server_side=True,
                                     do_handshake_on_connect=False,
                                     ssl_version=ssl.PROTOCOL_SSLv23)
            self.del_channel()
            self.set_socket(socket)
            self._ssl_accepting = True

        def _do_ssl_handshake(self):
            try:
                self.socket.do_handshake()
            except ssl.SSLError as err:
                if err.args[0] in (ssl.SSL_ERROR_WANT_READ,
                                   ssl.SSL_ERROR_WANT_WRITE):
                    return
                elif err.args[0] == ssl.SSL_ERROR_EOF:
                    return self.handle_close()
                raise
            except socket.error as err:
                if err.args[0] == errno.ECONNABORTED:
                    return self.handle_close()
            else:
                self._ssl_accepting = False

        def _do_ssl_shutdown(self):
            self._ssl_closing = True
            try:
                self.socket = self.socket.unwrap()
            except ssl.SSLError as err:
                if err.args[0] in (ssl.SSL_ERROR_WANT_READ,
                                   ssl.SSL_ERROR_WANT_WRITE):
                    return
            except socket.error as err:
                # Any "socket error" corresponds to a SSL_ERROR_SYSCALL return
                # from OpenSSL's SSL_shutdown(), corresponding to a
                # closed socket condition. See also:
                # http://www.mail-archive.com/openssl-users@openssl.org/msg60710.html
                pass
            self._ssl_closing = False
            if getattr(self, '_ccc', False) is False:
                super(SSLConnection, self).close()
            else:
                pass

        def handle_read_event(self):
            if self._ssl_accepting:
                self._do_ssl_handshake()
            elif self._ssl_closing:
                self._do_ssl_shutdown()
            else:
                super(SSLConnection, self).handle_read_event()

        def handle_write_event(self):
            if self._ssl_accepting:
                self._do_ssl_handshake()
            elif self._ssl_closing:
                self._do_ssl_shutdown()
            else:
                super(SSLConnection, self).handle_write_event()

        def send(self, data):
            try:
                return super(SSLConnection, self).send(data)
            except ssl.SSLError as err:
                if err.args[0] in (ssl.SSL_ERROR_EOF, ssl.SSL_ERROR_ZERO_RETURN,
                                   ssl.SSL_ERROR_WANT_READ,
                                   ssl.SSL_ERROR_WANT_WRITE):
                    return 0
                raise

        def recv(self, buffer_size):
            try:
                return super(SSLConnection, self).recv(buffer_size)
            except ssl.SSLError as err:
                if err.args[0] in (ssl.SSL_ERROR_WANT_READ,
                                   ssl.SSL_ERROR_WANT_WRITE):
                    return b''
                if err.args[0] in (ssl.SSL_ERROR_EOF, ssl.SSL_ERROR_ZERO_RETURN):
                    self.handle_close()
                    return b''
                raise

        def handle_error(self):
            raise

        def close(self):
            if (isinstance(self.socket, ssl.SSLSocket) and
                self.socket._sslobj is not None):
                self._do_ssl_shutdown()
            else:
                super(SSLConnection, self).close()


    class DummyTLS_DTPHandler(SSLConnection, DummyDTPHandler):
        """A DummyDTPHandler subclass supporting TLS/SSL."""

        def __init__(self, conn, baseclass):
            DummyDTPHandler.__init__(self, conn, baseclass)
            if self.baseclass.secure_data_channel:
                self.secure_connection()


    class DummyTLS_FTPHandler(SSLConnection, DummyFTPHandler):
        """A DummyFTPHandler subclass supporting TLS/SSL."""

        dtp_handler = DummyTLS_DTPHandler

        def __init__(self, conn):
            DummyFTPHandler.__init__(self, conn)
            self.secure_data_channel = False

        def cmd_auth(self, line):
            """Set up secure control channel."""
            self.push('234 AUTH TLS successful')
            self.secure_connection()

        def cmd_pbsz(self, line):
            """Negotiate size of buffer for secure data transfer.
            For TLS/SSL the only valid value for the parameter is '0'.
            Any other value is accepted but ignored.
            """
            self.push('200 PBSZ=0 successful.')

        def cmd_prot(self, line):
            """Setup un/secure data channel."""
            arg = line.upper()
            if arg == 'C':
                self.push('200 Protection set to Clear')
                self.secure_data_channel = False
            elif arg == 'P':
                self.push('200 Protection set to Private')
                self.secure_data_channel = True
            else:
                self.push("502 Unrecognized PROT type (use C or P).")


    class DummyTLS_FTPServer(DummyFTPServer):
        handler = DummyTLS_FTPHandler


class TestFTPClass(TestCase):

    def setUp(self):
        self.server = DummyFTPServer((HOST, 0))
        self.server.start()
        self.client = ftplib.FTP(timeout=10)
        self.client.connect(self.server.host, self.server.port)

    def tearDown(self):
        self.client.close()
        self.server.stop()

    def test_getwelcome(self):
        self.assertEqual(self.client.getwelcome(), '220 welcome')

    def test_sanitize(self):
        self.assertEqual(self.client.sanitize('foo'), repr('foo'))
        self.assertEqual(self.client.sanitize('pass 12345'), repr('pass *****'))
        self.assertEqual(self.client.sanitize('PASS 12345'), repr('PASS *****'))

    def test_exceptions(self):
        self.assertRaises(ftplib.error_temp, self.client.sendcmd, 'echo 400')
        self.assertRaises(ftplib.error_temp, self.client.sendcmd, 'echo 499')
        self.assertRaises(ftplib.error_perm, self.client.sendcmd, 'echo 500')
        self.assertRaises(ftplib.error_perm, self.client.sendcmd, 'echo 599')
        self.assertRaises(ftplib.error_proto, self.client.sendcmd, 'echo 999')

    def test_all_errors(self):
        exceptions = (ftplib.error_reply, ftplib.error_temp, ftplib.error_perm,
                      ftplib.error_proto, ftplib.Error, IOError, EOFError)
        for x in exceptions:
            try:
                raise x('exception not included in all_errors set')
            except ftplib.all_errors:
                pass

    def test_set_pasv(self):
        # passive mode is supposed to be enabled by default
        self.assertTrue(self.client.passiveserver)
        self.client.set_pasv(True)
        self.assertTrue(self.client.passiveserver)
        self.client.set_pasv(False)
        self.assertFalse(self.client.passiveserver)

    def test_voidcmd(self):
        self.client.voidcmd('echo 200')
        self.client.voidcmd('echo 299')
        self.assertRaises(ftplib.error_reply, self.client.voidcmd, 'echo 199')
        self.assertRaises(ftplib.error_reply, self.client.voidcmd, 'echo 300')

    def test_login(self):
        self.client.login()

    def test_acct(self):
        self.client.acct('passwd')

    def test_rename(self):
        self.client.rename('a', 'b')
        self.server.handler_instance.next_response = '200'
        self.assertRaises(ftplib.error_reply, self.client.rename, 'a', 'b')

    def test_delete(self):
        self.client.delete('foo')
        self.server.handler_instance.next_response = '199'
        self.assertRaises(ftplib.error_reply, self.client.delete, 'foo')

    def test_size(self):
        self.client.size('foo')

    def test_mkd(self):
        dir = self.client.mkd('/foo')
        self.assertEqual(dir, '/foo')

    def test_rmd(self):
        self.client.rmd('foo')

    def test_cwd(self):
        dir = self.client.cwd('/foo')
        self.assertEqual(dir, '250 cwd ok')

    def test_pwd(self):
        dir = self.client.pwd()
        self.assertEqual(dir, 'pwd ok')

    def test_quit(self):
        self.assertEqual(self.client.quit(), '221 quit ok')
        # Ensure the connection gets closed; sock attribute should be None
        self.assertEqual(self.client.sock, None)

    def test_retrbinary(self):
        received = []
        self.client.retrbinary('retr', received.append)
        self.assertEqual(''.join(received), RETR_DATA)

    def test_retrbinary_rest(self):
        for rest in (0, 10, 20):
            received = []
            self.client.retrbinary('retr', received.append, rest=rest)
            self.assertEqual(''.join(received), RETR_DATA[rest:],
                             msg='rest test case %d %d %d' % (rest,
                                                              len(''.join(received)),
                                                              len(RETR_DATA[rest:])))

    def test_retrlines(self):
        received = []
        self.client.retrlines('retr', received.append)
        self.assertEqual(''.join(received), RETR_DATA.replace('\r\n', ''))

    def test_storbinary(self):
        f = StringIO.StringIO(RETR_DATA)
        self.client.storbinary('stor', f)
        self.assertEqual(self.server.handler_instance.last_received_data, RETR_DATA)
        # test new callback arg
        flag = []
        f.seek(0)
        self.client.storbinary('stor', f, callback=lambda x: flag.append(None))
        self.assertTrue(flag)

    def test_storbinary_rest(self):
        f = StringIO.StringIO(RETR_DATA)
        for r in (30, '30'):
            f.seek(0)
            self.client.storbinary('stor', f, rest=r)
            self.assertEqual(self.server.handler_instance.rest, str(r))

    def test_storlines(self):
        f = StringIO.StringIO(RETR_DATA.replace('\r\n', '\n'))
        self.client.storlines('stor', f)
        self.assertEqual(self.server.handler_instance.last_received_data, RETR_DATA)
        # test new callback arg
        flag = []
        f.seek(0)
        self.client.storlines('stor foo', f, callback=lambda x: flag.append(None))
        self.assertTrue(flag)

    def test_nlst(self):
        self.client.nlst()
        self.assertEqual(self.client.nlst(), NLST_DATA.split('\r\n')[:-1])

    def test_dir(self):
        l = []
        self.client.dir(lambda x: l.append(x))
        self.assertEqual(''.join(l), LIST_DATA.replace('\r\n', ''))

    def test_makeport(self):
        self.client.makeport()
        # IPv4 is in use, just make sure send_eprt has not been used
        self.assertEqual(self.server.handler_instance.last_received_cmd, 'port')

    def test_makepasv(self):
        host, port = self.client.makepasv()
        conn = socket.create_connection((host, port), 10)
        conn.close()
        # IPv4 is in use, just make sure send_epsv has not been used
        self.assertEqual(self.server.handler_instance.last_received_cmd, 'pasv')

    def test_line_too_long(self):
        self.assertRaises(ftplib.Error, self.client.sendcmd,
                          'x' * self.client.maxline * 2)

    def test_retrlines_too_long(self):
        self.client.sendcmd('SETLONGRETR %d' % (self.client.maxline * 2))
        received = []
        self.assertRaises(ftplib.Error,
                          self.client.retrlines, 'retr', received.append)

    def test_storlines_too_long(self):
        f = StringIO.StringIO('x' * self.client.maxline * 2)
        self.assertRaises(ftplib.Error, self.client.storlines, 'stor', f)


@skipUnless(socket.has_ipv6, "IPv6 not enabled")
class TestIPv6Environment(TestCase):

    @classmethod
    def setUpClass(cls):
        try:
            DummyFTPServer((HOST, 0), af=socket.AF_INET6)
        except socket.error:
            raise SkipTest("IPv6 not enabled")

    def setUp(self):
        self.server = DummyFTPServer((HOSTv6, 0), af=socket.AF_INET6)
        self.server.start()
        self.client = ftplib.FTP()
        self.client.connect(self.server.host, self.server.port)

    def tearDown(self):
        self.client.close()
        self.server.stop()

    def test_af(self):
        self.assertEqual(self.client.af, socket.AF_INET6)

    def test_makeport(self):
        self.client.makeport()
        self.assertEqual(self.server.handler_instance.last_received_cmd, 'eprt')

    def test_makepasv(self):
        host, port = self.client.makepasv()
        conn = socket.create_connection((host, port), 10)
        conn.close()
        self.assertEqual(self.server.handler_instance.last_received_cmd, 'epsv')

    def test_transfer(self):
        def retr():
            received = []
            self.client.retrbinary('retr', received.append)
            self.assertEqual(''.join(received), RETR_DATA)
        self.client.set_pasv(True)
        retr()
        self.client.set_pasv(False)
        retr()


@skipUnless(ssl, "SSL not available")
class TestTLS_FTPClassMixin(TestFTPClass):
    """Repeat TestFTPClass tests starting the TLS layer for both control
    and data connections first.
    """

    def setUp(self):
        self.server = DummyTLS_FTPServer((HOST, 0))
        self.server.start()
        self.client = ftplib.FTP_TLS(timeout=10)
        self.client.connect(self.server.host, self.server.port)
        # enable TLS
        self.client.auth()
        self.client.prot_p()


@skipUnless(ssl, "SSL not available")
class TestTLS_FTPClass(TestCase):
    """Specific TLS_FTP class tests."""

    def setUp(self):
        self.server = DummyTLS_FTPServer((HOST, 0))
        self.server.start()
        self.client = ftplib.FTP_TLS(timeout=TIMEOUT)
        self.client.connect(self.server.host, self.server.port)

    def tearDown(self):
        self.client.close()
        self.server.stop()

    def test_control_connection(self):
        self.assertNotIsInstance(self.client.sock, ssl.SSLSocket)
        self.client.auth()
        self.assertIsInstance(self.client.sock, ssl.SSLSocket)

    def test_data_connection(self):
        # clear text
        sock = self.client.transfercmd('list')
        self.assertNotIsInstance(sock, ssl.SSLSocket)
        sock.close()
        self.assertEqual(self.client.voidresp(), "226 transfer complete")

        # secured, after PROT P
        self.client.prot_p()
        sock = self.client.transfercmd('list')
        self.assertIsInstance(sock, ssl.SSLSocket)
        sock.close()
        self.assertEqual(self.client.voidresp(), "226 transfer complete")

        # PROT C is issued, the connection must be in cleartext again
        self.client.prot_c()
        sock = self.client.transfercmd('list')
        self.assertNotIsInstance(sock, ssl.SSLSocket)
        sock.close()
        self.assertEqual(self.client.voidresp(), "226 transfer complete")

    def test_login(self):
        # login() is supposed to implicitly secure the control connection
        self.assertNotIsInstance(self.client.sock, ssl.SSLSocket)
        self.client.login()
        self.assertIsInstance(self.client.sock, ssl.SSLSocket)
        # make sure that AUTH TLS doesn't get issued again
        self.client.login()

    def test_auth_issued_twice(self):
        self.client.auth()
        self.assertRaises(ValueError, self.client.auth)

    def test_auth_ssl(self):
        try:
            self.client.ssl_version = ssl.PROTOCOL_SSLv23
            self.client.auth()
            self.assertRaises(ValueError, self.client.auth)
        finally:
            self.client.ssl_version = ssl.PROTOCOL_TLSv1

    def test_context(self):
        self.client.quit()
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        self.assertRaises(ValueError, ftplib.FTP_TLS, keyfile=CERTFILE,
                          context=ctx)
        self.assertRaises(ValueError, ftplib.FTP_TLS, certfile=CERTFILE,
                          context=ctx)
        self.assertRaises(ValueError, ftplib.FTP_TLS, certfile=CERTFILE,
                          keyfile=CERTFILE, context=ctx)

        self.client = ftplib.FTP_TLS(context=ctx, timeout=TIMEOUT)
        self.client.connect(self.server.host, self.server.port)
        self.assertNotIsInstance(self.client.sock, ssl.SSLSocket)
        self.client.auth()
        self.assertIs(self.client.sock.context, ctx)
        self.assertIsInstance(self.client.sock, ssl.SSLSocket)

        self.client.prot_p()
        sock = self.client.transfercmd('list')
        try:
            self.assertIs(sock.context, ctx)
            self.assertIsInstance(sock, ssl.SSLSocket)
        finally:
            sock.close()

    def test_check_hostname(self):
        self.client.quit()
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        ctx.verify_mode = ssl.CERT_REQUIRED
        ctx.check_hostname = True
        ctx.load_verify_locations(CAFILE)
        self.client = ftplib.FTP_TLS(context=ctx, timeout=TIMEOUT)

        # 127.0.0.1 doesn't match SAN
        self.client.connect(self.server.host, self.server.port)
        with self.assertRaises(ssl.CertificateError):
            self.client.auth()
        # exception quits connection

        self.client.connect(self.server.host, self.server.port)
        self.client.prot_p()
        with self.assertRaises(ssl.CertificateError):
            self.client.transfercmd("list").close()
        self.client.quit()

        self.client.connect("localhost", self.server.port)
        self.client.auth()
        self.client.quit()

        self.client.connect("localhost", self.server.port)
        self.client.prot_p()
        self.client.transfercmd("list").close()


class TestTimeouts(TestCase):

    def setUp(self):
        self.evt = threading.Event()
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.settimeout(10)
        self.port = test_support.bind_port(self.sock)
        threading.Thread(target=self.server, args=(self.evt,self.sock)).start()
        # Wait for the server to be ready.
        self.evt.wait()
        self.evt.clear()
        ftplib.FTP.port = self.port

    def tearDown(self):
        self.evt.wait()

    def server(self, evt, serv):
        # This method sets the evt 3 times:
        #  1) when the connection is ready to be accepted.
        #  2) when it is safe for the caller to close the connection
        #  3) when we have closed the socket
        serv.listen(5)
        # (1) Signal the caller that we are ready to accept the connection.
        evt.set()
        try:
            conn, addr = serv.accept()
        except socket.timeout:
            pass
        else:
            conn.send("1 Hola mundo\n")
            # (2) Signal the caller that it is safe to close the socket.
            evt.set()
            conn.close()
        finally:
            serv.close()
            # (3) Signal the caller that we are done.
            evt.set()

    def testTimeoutDefault(self):
        # default -- use global socket timeout
        self.assertIsNone(socket.getdefaulttimeout())
        socket.setdefaulttimeout(30)
        try:
            ftp = ftplib.FTP(HOST)
        finally:
            socket.setdefaulttimeout(None)
        self.assertEqual(ftp.sock.gettimeout(), 30)
        self.evt.wait()
        ftp.close()

    def testTimeoutNone(self):
        # no timeout -- do not use global socket timeout
        self.assertIsNone(socket.getdefaulttimeout())
        socket.setdefaulttimeout(30)
        try:
            ftp = ftplib.FTP(HOST, timeout=None)
        finally:
            socket.setdefaulttimeout(None)
        self.assertIsNone(ftp.sock.gettimeout())
        self.evt.wait()
        ftp.close()

    def testTimeoutValue(self):
        # a value
        ftp = ftplib.FTP(HOST, timeout=30)
        self.assertEqual(ftp.sock.gettimeout(), 30)
        self.evt.wait()
        ftp.close()

    def testTimeoutConnect(self):
        ftp = ftplib.FTP()
        ftp.connect(HOST, timeout=30)
        self.assertEqual(ftp.sock.gettimeout(), 30)
        self.evt.wait()
        ftp.close()

    def testTimeoutDifferentOrder(self):
        ftp = ftplib.FTP(timeout=30)
        ftp.connect(HOST)
        self.assertEqual(ftp.sock.gettimeout(), 30)
        self.evt.wait()
        ftp.close()

    def testTimeoutDirectAccess(self):
        ftp = ftplib.FTP()
        ftp.timeout = 30
        ftp.connect(HOST)
        self.assertEqual(ftp.sock.gettimeout(), 30)
        self.evt.wait()
        ftp.close()


def test_main():
    tests = [TestFTPClass, TestTimeouts,
             TestIPv6Environment,
             TestTLS_FTPClassMixin, TestTLS_FTPClass]

    thread_info = test_support.threading_setup()
    try:
        test_support.run_unittest(*tests)
    finally:
        test_support.threading_cleanup(*thread_info)


if __name__ == '__main__':
    test_main()