"""Unit tests for socket timeout feature."""
import functools
import unittest
from test import support
# This requires the 'network' resource as given on the regrtest command line.
skip_expected = not support.is_resource_enabled('network')
import time
import errno
import socket
@functools.lru_cache()
def resolve_address(host, port):
"""Resolve an (host, port) to an address.
We must perform name resolution before timeout tests, otherwise it will be
performed by connect().
"""
with support.transient_internet(host):
return socket.getaddrinfo(host, port, socket.AF_INET,
socket.SOCK_STREAM)[0][4]
class CreationTestCase(unittest.TestCase):
"""Test case for socket.gettimeout() and socket.settimeout()"""
def setUp(self):
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
def tearDown(self):
self.sock.close()
def testObjectCreation(self):
# Test Socket creation
self.assertEqual(self.sock.gettimeout(), None,
"timeout not disabled by default")
def testFloatReturnValue(self):
# Test return value of gettimeout()
self.sock.settimeout(7.345)
self.assertEqual(self.sock.gettimeout(), 7.345)
self.sock.settimeout(3)
self.assertEqual(self.sock.gettimeout(), 3)
self.sock.settimeout(None)
self.assertEqual(self.sock.gettimeout(), None)
def testReturnType(self):
# Test return type of gettimeout()
self.sock.settimeout(1)
self.assertEqual(type(self.sock.gettimeout()), type(1.0))
self.sock.settimeout(3.9)
self.assertEqual(type(self.sock.gettimeout()), type(1.0))
def testTypeCheck(self):
# Test type checking by settimeout()
self.sock.settimeout(0)
self.sock.settimeout(0)
self.sock.settimeout(0.0)
self.sock.settimeout(None)
self.assertRaises(TypeError, self.sock.settimeout, "")
self.assertRaises(TypeError, self.sock.settimeout, "")
self.assertRaises(TypeError, self.sock.settimeout, ())
self.assertRaises(TypeError, self.sock.settimeout, [])
self.assertRaises(TypeError, self.sock.settimeout, {})
self.assertRaises(TypeError, self.sock.settimeout, 0j)
def testRangeCheck(self):
# Test range checking by settimeout()
self.assertRaises(ValueError, self.sock.settimeout, -1)
self.assertRaises(ValueError, self.sock.settimeout, -1)
self.assertRaises(ValueError, self.sock.settimeout, -1.0)
def testTimeoutThenBlocking(self):
# Test settimeout() followed by setblocking()
self.sock.settimeout(10)
self.sock.setblocking(1)
self.assertEqual(self.sock.gettimeout(), None)
self.sock.setblocking(0)
self.assertEqual(self.sock.gettimeout(), 0.0)
self.sock.settimeout(10)
self.sock.setblocking(0)
self.assertEqual(self.sock.gettimeout(), 0.0)
self.sock.setblocking(1)
self.assertEqual(self.sock.gettimeout(), None)
def testBlockingThenTimeout(self):
# Test setblocking() followed by settimeout()
self.sock.setblocking(0)
self.sock.settimeout(1)
self.assertEqual(self.sock.gettimeout(), 1)
self.sock.setblocking(1)
self.sock.settimeout(1)
self.assertEqual(self.sock.gettimeout(), 1)
class TimeoutTestCase(unittest.TestCase):
# There are a number of tests here trying to make sure that an operation
# doesn't take too much longer than expected. But competing machine
# activity makes it inevitable that such tests will fail at times.
# When fuzz was at 1.0, I (tim) routinely saw bogus failures on Win2K
# and Win98SE. Boosting it to 2.0 helped a lot, but isn't a real
# solution.
fuzz = 2.0
localhost = support.HOST
def setUp(self):
raise NotImplementedError()
tearDown = setUp
def _sock_operation(self, count, timeout, method, *args):
"""
Test the specified socket method.
The method is run at most `count` times and must raise a socket.timeout
within `timeout` + self.fuzz seconds.
"""
self.sock.settimeout(timeout)
method = getattr(self.sock, method)
for i in range(count):
t1 = time.time()
try:
method(*args)
except socket.timeout as e:
delta = time.time() - t1
break
else:
self.fail('socket.timeout was not raised')
# These checks should account for timing unprecision
self.assertLess(delta, timeout + self.fuzz)
self.assertGreater(delta, timeout - 1.0)
class TCPTimeoutTestCase(TimeoutTestCase):
"""TCP test case for socket.socket() timeout functions"""
def setUp(self):
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.addr_remote = resolve_address('www.python.org.', 80)
def tearDown(self):
self.sock.close()
def testConnectTimeout(self):
# Testing connect timeout is tricky: we need to have IP connectivity
# to a host that silently drops our packets. We can't simulate this
# from Python because it's a function of the underlying TCP/IP stack.
# So, the following Snakebite host has been defined:
blackhole = resolve_address('blackhole.snakebite.net', 56666)
# Blackhole has been configured to silently drop any incoming packets.
# No RSTs (for TCP) or ICMP UNREACH (for UDP/ICMP) will be sent back
# to hosts that attempt to connect to this address: which is exactly
# what we need to confidently test connect timeout.
# However, we want to prevent false positives. It's not unreasonable
# to expect certain hosts may not be able to reach the blackhole, due
# to firewalling or general network configuration. In order to improve
# our confidence in testing the blackhole, a corresponding 'whitehole'
# has also been set up using one port higher:
whitehole = resolve_address('whitehole.snakebite.net', 56667)
# This address has been configured to immediately drop any incoming
# packets as well, but it does it respectfully with regards to the
# incoming protocol. RSTs are sent for TCP packets, and ICMP UNREACH
# is sent for UDP/ICMP packets. This means our attempts to connect to
# it should be met immediately with ECONNREFUSED. The test case has
# been structured around this premise: if we get an ECONNREFUSED from
# the whitehole, we proceed with testing connect timeout against the
# blackhole. If we don't, we skip the test (with a message about not
# getting the required RST from the whitehole within the required
# timeframe).
# For the records, the whitehole/blackhole configuration has been set
# up using the 'pf' firewall (available on BSDs), using the following:
#
# ext_if="bge0"
#
# blackhole_ip="35.8.247.6"
# whitehole_ip="35.8.247.6"
# blackhole_port="56666"
# whitehole_port="56667"
#
# block return in log quick on $ext_if proto { tcp udp } \
# from any to $whitehole_ip port $whitehole_port
# block drop in log quick on $ext_if proto { tcp udp } \
# from any to $blackhole_ip port $blackhole_port
#
skip = True
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Use a timeout of 3 seconds. Why 3? Because it's more than 1, and
# less than 5. i.e. no particular reason. Feel free to tweak it if
# you feel a different value would be more appropriate.
timeout = 3
sock.settimeout(timeout)
try:
sock.connect((whitehole))
except socket.timeout:
pass
except OSError as err:
if err.errno == errno.ECONNREFUSED:
skip = False
finally:
sock.close()
del sock
if skip:
self.skipTest(
"We didn't receive a connection reset (RST) packet from "
"{}:{} within {} seconds, so we're unable to test connect "
"timeout against the corresponding {}:{} (which is "
"configured to silently drop packets)."
.format(
whitehole[0],
whitehole[1],
timeout,
blackhole[0],
blackhole[1],
)
)
# All that hard work just to test if connect times out in 0.001s ;-)
self.addr_remote = blackhole
with support.transient_internet(self.addr_remote[0]):
self._sock_operation(1, 0.001, 'connect', self.addr_remote)
def testRecvTimeout(self):
# Test recv() timeout
with support.transient_internet(self.addr_remote[0]):
self.sock.connect(self.addr_remote)
self._sock_operation(1, 1.5, 'recv', 1024)
def testAcceptTimeout(self):
# Test accept() timeout
support.bind_port(self.sock, self.localhost)
self.sock.listen(5)
self._sock_operation(1, 1.5, 'accept')
def testSend(self):
# Test send() timeout
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
support.bind_port(serv, self.localhost)
serv.listen(5)
self.sock.connect(serv.getsockname())
# Send a lot of data in order to bypass buffering in the TCP stack.
self._sock_operation(100, 1.5, 'send', b"X" * 200000)
def testSendto(self):
# Test sendto() timeout
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
support.bind_port(serv, self.localhost)
serv.listen(5)
self.sock.connect(serv.getsockname())
# The address argument is ignored since we already connected.
self._sock_operation(100, 1.5, 'sendto', b"X" * 200000,
serv.getsockname())
def testSendall(self):
# Test sendall() timeout
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
support.bind_port(serv, self.localhost)
serv.listen(5)
self.sock.connect(serv.getsockname())
# Send a lot of data in order to bypass buffering in the TCP stack.
self._sock_operation(100, 1.5, 'sendall', b"X" * 200000)
class UDPTimeoutTestCase(TimeoutTestCase):
"""UDP test case for socket.socket() timeout functions"""
def setUp(self):
self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
def tearDown(self):
self.sock.close()
def testRecvfromTimeout(self):
# Test recvfrom() timeout
# Prevent "Address already in use" socket exceptions
support.bind_port(self.sock, self.localhost)
self._sock_operation(1, 1.5, 'recvfrom', 1024)
def test_main():
support.requires('network')
support.run_unittest(
CreationTestCase,
TCPTimeoutTestCase,
UDPTimeoutTestCase,
)
if __name__ == "__main__":
test_main()