"""Unit tests for socket timeout feature.""" 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 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 = '127.0.0.1' 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 = ('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 = ('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 = ('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 IOError 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()