def test__build(self):
mac = factory.getRandomMACAddress()
discover = DHCPDiscoverPacket(mac)
discover._build()
expected = (b'\x01\x01\x06\x00' + discover.transaction_ID +
b'\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00' +
b'\x00\x00\x00\x00\x00\x00\x00\x00' + discover.packed_mac +
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' +
b'\x00' * 67 + b'\x00' * 125 +
b'\x63\x82\x53\x63\x35\x01\x01\x3d\x06' +
discover.packed_mac + b'\x37\x03\x03\x01\x06\xff')
self.assertEqual(expected, discover.packet)
def test__deferDHCPRequests(self):
clock = Clock()
monitor = DHCPRequestMonitor('lo', clock)
mock_addErrback = mock.MagicMock()
mock_deferredListResult = mock.MagicMock()
mock_deferLater = self.patch(detect_module, 'deferLater')
mock_deferLater.return_value = mock.MagicMock()
mock_deferLater.return_value.addErrback = mock_addErrback
mock_DeferredList = self.patch(detect_module, 'DeferredList')
mock_DeferredList.return_value = mock_deferredListResult
mock_deferredListResult.addErrback = mock_addErrback
expected_calls = [
call(
clock, seconds + 0.1, send_dhcp_request_packet,
DHCPDiscoverPacket(transaction_id=monitor.transaction_id,
seconds=seconds), 'lo')
for seconds in DHCP_REQUEST_TIMING
]
monitor.deferDHCPRequests()
self.assertThat(mock_deferLater, MockCallsMatch(*expected_calls))
self.assertThat(
mock_DeferredList,
MockCallsMatch(
call(monitor.deferredDHCPRequests,
fireOnOneErrback=True,
consumeErrors=True)))
# Expect addErrback to be called both on each individual Deferred, plus
# one more time on the DeferredList.
expected_errback_calls = [
call(monitor.deferredDHCPRequestErrback)
for _ in range(len(DHCP_REQUEST_TIMING) + 1)
]
self.assertThat(mock_addErrback,
MockCallsMatch(*expected_errback_calls))
def test_init_sets_transaction_ID(self):
transaction_id = make_transaction_ID()
self.patch(detect_module,
'make_transaction_ID').return_value = (transaction_id)
discover = DHCPDiscoverPacket(factory.getRandomMACAddress())
self.assertEqual(transaction_id, discover.transaction_ID)
def test__sends_expected_packet(self):
mock_socket = patch_socket(self)
mock_socket.bind = mock.MagicMock()
mock_socket.sendto = mock.MagicMock()
self.patch(detect_module.get_interface_ip).return_value = '127.0.0.1'
self.patch(
detect_module.get_interface_mac).return_value = '00:00:00:00:00:00'
request = DHCPDiscoverPacket()
send_dhcp_request_packet(request, 'lo')
self.assertThat(mock_socket.bind,
MockCallsMatch(call(('127.0.0.1', BOOTP_CLIENT_PORT))))
self.assertThat(
mock_socket.sendto,
MockCallsMatch(
call(request.packet, ('<broadcast>', BOOTP_SERVER_PORT))))
def test__builds_packet(self):
mac = factory.make_mac_address()
seconds = random.randint(0, 1024)
xid = factory.make_bytes(4)
discover = DHCPDiscoverPacket(transaction_id=xid,
mac=mac,
seconds=seconds)
seconds_bytes = seconds.to_bytes(2, "big")
expected = (b"\x01\x01\x06\x00" + xid + seconds_bytes +
b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" +
b"\x00\x00\x00\x00\x00\x00" + discover.mac_bytes +
b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" +
b"\x00" * 67 + b"\x00" * 125 +
b"\x63\x82\x53\x63\x35\x01\x01" +
discover.client_uid_option + b"\x37\x03\x03\x01\x06\xff")
self.assertEqual(expected, discover.packet)
def test__packet_property_after_init_with_mac_and_no_transaction_id(self):
discover = DHCPDiscoverPacket(factory.make_mac_address())
self.assertIsNotNone(discover.packet)
def test_init_sets_mac_bytes(self):
mac = factory.make_mac_address()
discover = DHCPDiscoverPacket(mac)
self.assertEqual(discover.mac_string_to_bytes(mac), discover.mac_bytes)
def test_init_sets_transaction_id(self):
transaction_id = make_dhcp_transaction_id()
self.patch(detect_module,
"make_dhcp_transaction_id").return_value = transaction_id
discover = DHCPDiscoverPacket(factory.make_mac_address())
self.assertEqual(transaction_id, discover.transaction_id)
def test__send_requests_and_await_replies(self):
# This test is a bit large because it covers the entire functionality
# of the `send_requests_and_await_replies()` method. (It could be
# split apart into multiple tests, but the large amount of setup work
# and interdependencies makes that a maintenance burden.)
mock_socket = patch_socket(self)
mock_socket.bind = mock.MagicMock()
mock_socket.recvfrom = mock.MagicMock()
mock_socket.setsockopt = mock.MagicMock()
mock_socket.settimeout = mock.MagicMock()
# Pretend we were successful at deferring the DHCP requests.
self.patch_autospec(detect_module, "blockingCallFromThread")
# This method normally blocks for ~10 seconds, so take control of the
# monotonic clock and make sure the last call to `recvfrom()` happens
# just as we hit the reply timeout.
mock_time_monotonic = self.patch(detect_module.time.monotonic)
mock_time_monotonic.side_effect = (
# Start time (before loop starts).
10,
# First reply (truncated packet).
11,
# Second reply (not a match to our transaction).
12,
# Third reply (Matching reply with server identifier option).
13,
# First socket timeout (need to make sure the loop continues).
14,
# Second socket timeout (hey, we're done!).
10 + detect_module.REPLY_TIMEOUT,
)
mock_xid = factory.make_bytes(4)
valid_dhcp_reply = factory.make_dhcp_packet(
transaction_id=mock_xid,
include_server_identifier=True,
server_ip="127.1.1.1",
)
mock_get_xid = self.patch(detect_module.make_dhcp_transaction_id)
mock_get_xid.return_value = mock_xid
# Valid DHCP packet, but not a match because it doesn't have a
# Server Identifier option.
valid_non_match = DHCPDiscoverPacket(mac="01:02:03:04:05:06",
transaction_id=mock_xid).packet
mock_socket.recvfrom.side_effect = (
# Truncated packet, to test logging.
(b"", ("127.0.0.1", BOOTP_SERVER_PORT)),
(valid_non_match, ("127.0.0.2", BOOTP_SERVER_PORT)),
(valid_dhcp_reply, ("127.0.0.3", BOOTP_SERVER_PORT)),
socket.timeout,
socket.timeout,
)
logger = self.useFixture(TwistedLoggerFixture())
monitor = DHCPRequestMonitor("lo", Clock())
result = monitor.send_requests_and_await_replies()
self.assertThat(
mock_socket.setsockopt,
MockCallsMatch(
call(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1),
call(socket.SOL_SOCKET, socket.SO_BROADCAST, 1),
),
)
self.assertThat(mock_socket.bind, MockCallsMatch(call(("", 68))))
self.assertThat(
mock_socket.settimeout,
MockCallsMatch(call(detect_module.SOCKET_TIMEOUT)),
)
self.assertThat(
mock_socket.recvfrom,
MockCallsMatch(call(2048), call(2048), call(2048), call(2048),
call(2048)),
)
# One of the response packets was truncated.
self.assertThat(
logger.output,
DocTestMatches("Invalid DHCP response...Truncated..."),
)
self.assertThat(result, HasLength(1))
# Ensure we record the fact that the reply packet came from a different
# IP address than the server claimed to be.
self.assertThat(result, Contains(DHCPServer("127.1.1.1", "127.0.0.3")))
def test_init_sets_packet(self):
discover = DHCPDiscoverPacket(factory.getRandomMACAddress())
self.assertIsNotNone(discover.packet)
def test_init_sets_packed_mac(self):
mac = factory.getRandomMACAddress()
discover = DHCPDiscoverPacket(mac)
self.assertEqual(discover.string_mac_to_packed(mac),
discover.packed_mac)