# Author: Tamilmani Manoharan <tamanoha@microsoft.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
from cloudinit.tests.helpers import CiTestCase, mock
import socket
import struct
import codecs
from cloudinit.sources.helpers.netlink import (
NetlinkCreateSocketError, create_bound_netlink_socket, read_netlink_socket,
read_rta_oper_state, unpack_rta_attr, wait_for_media_disconnect_connect,
OPER_DOWN, OPER_UP, OPER_DORMANT, OPER_LOWERLAYERDOWN, OPER_NOTPRESENT,
OPER_TESTING, OPER_UNKNOWN, RTATTR_START_OFFSET, RTM_NEWLINK, RTM_SETLINK,
RTM_GETLINK, MAX_SIZE)
def int_to_bytes(i):
'''convert integer to binary: eg: 1 to \x01'''
hex_value = '{0:x}'.format(i)
hex_value = '0' * (len(hex_value) % 2) + hex_value
return codecs.decode(hex_value, 'hex_codec')
class TestCreateBoundNetlinkSocket(CiTestCase):
@mock.patch('cloudinit.sources.helpers.netlink.socket.socket')
def test_socket_error_on_create(self, m_socket):
'''create_bound_netlink_socket catches socket creation exception'''
"""NetlinkCreateSocketError is raised when socket creation errors."""
m_socket.side_effect = socket.error("Fake socket failure")
with self.assertRaises(NetlinkCreateSocketError) as ctx_mgr:
create_bound_netlink_socket()
self.assertEqual(
'Exception during netlink socket create: Fake socket failure',
str(ctx_mgr.exception))
class TestReadNetlinkSocket(CiTestCase):
@mock.patch('cloudinit.sources.helpers.netlink.socket.socket')
@mock.patch('cloudinit.sources.helpers.netlink.select.select')
def test_read_netlink_socket(self, m_select, m_socket):
'''read_netlink_socket able to receive data'''
data = 'netlinktest'
m_select.return_value = [m_socket], None, None
m_socket.recv.return_value = data
recv_data = read_netlink_socket(m_socket, 2)
m_select.assert_called_with([m_socket], [], [], 2)
m_socket.recv.assert_called_with(MAX_SIZE)
self.assertIsNotNone(recv_data)
self.assertEqual(recv_data, data)
@mock.patch('cloudinit.sources.helpers.netlink.socket.socket')
@mock.patch('cloudinit.sources.helpers.netlink.select.select')
def test_netlink_read_timeout(self, m_select, m_socket):
'''read_netlink_socket should timeout if nothing to read'''
m_select.return_value = [], None, None
data = read_netlink_socket(m_socket, 1)
m_select.assert_called_with([m_socket], [], [], 1)
self.assertEqual(m_socket.recv.call_count, 0)
self.assertIsNone(data)
def test_read_invalid_socket(self):
'''read_netlink_socket raises assert error if socket is invalid'''
socket = None
with self.assertRaises(AssertionError) as context:
read_netlink_socket(socket, 1)
self.assertTrue('netlink socket is none' in str(context.exception))
class TestParseNetlinkMessage(CiTestCase):
def test_read_rta_oper_state(self):
'''read_rta_oper_state could parse netlink message and extract data'''
ifname = "eth0"
bytes = ifname.encode("utf-8")
buf = bytearray(48)
struct.pack_into("HH4sHHc", buf, RTATTR_START_OFFSET, 8, 3, bytes, 5,
16, int_to_bytes(OPER_DOWN))
interface_state = read_rta_oper_state(buf)
self.assertEqual(interface_state.ifname, ifname)
self.assertEqual(interface_state.operstate, OPER_DOWN)
def test_read_none_data(self):
'''read_rta_oper_state raises assert error if data is none'''
data = None
with self.assertRaises(AssertionError) as context:
read_rta_oper_state(data)
self.assertEqual('data is none', str(context.exception))
def test_read_invalid_rta_operstate_none(self):
'''read_rta_oper_state returns none if operstate is none'''
ifname = "eth0"
buf = bytearray(40)
bytes = ifname.encode("utf-8")
struct.pack_into("HH4s", buf, RTATTR_START_OFFSET, 8, 3, bytes)
interface_state = read_rta_oper_state(buf)
self.assertIsNone(interface_state)
def test_read_invalid_rta_ifname_none(self):
'''read_rta_oper_state returns none if ifname is none'''
buf = bytearray(40)
struct.pack_into("HHc", buf, RTATTR_START_OFFSET, 5, 16,
int_to_bytes(OPER_DOWN))
interface_state = read_rta_oper_state(buf)
self.assertIsNone(interface_state)
def test_read_invalid_data_len(self):
'''raise assert error if data size is smaller than required size'''
buf = bytearray(32)
with self.assertRaises(AssertionError) as context:
read_rta_oper_state(buf)
self.assertTrue('length of data is smaller than RTATTR_START_OFFSET' in
str(context.exception))
def test_unpack_rta_attr_none_data(self):
'''unpack_rta_attr raises assert error if data is none'''
data = None
with self.assertRaises(AssertionError) as context:
unpack_rta_attr(data, RTATTR_START_OFFSET)
self.assertTrue('data is none' in str(context.exception))
def test_unpack_rta_attr_invalid_offset(self):
'''unpack_rta_attr raises assert error if offset is invalid'''
data = bytearray(48)
with self.assertRaises(AssertionError) as context:
unpack_rta_attr(data, "offset")
self.assertTrue('offset is not integer' in str(context.exception))
with self.assertRaises(AssertionError) as context:
unpack_rta_attr(data, 31)
self.assertTrue('rta offset is less than expected length' in
str(context.exception))
@mock.patch('cloudinit.sources.helpers.netlink.socket.socket')
@mock.patch('cloudinit.sources.helpers.netlink.read_netlink_socket')
class TestWaitForMediaDisconnectConnect(CiTestCase):
with_logs = True
def _media_switch_data(self, ifname, msg_type, operstate):
'''construct netlink data with specified fields'''
if ifname and operstate is not None:
data = bytearray(48)
bytes = ifname.encode("utf-8")
struct.pack_into("HH4sHHc", data, RTATTR_START_OFFSET, 8, 3,
bytes, 5, 16, int_to_bytes(operstate))
elif ifname:
data = bytearray(40)
bytes = ifname.encode("utf-8")
struct.pack_into("HH4s", data, RTATTR_START_OFFSET, 8, 3, bytes)
elif operstate:
data = bytearray(40)
struct.pack_into("HHc", data, RTATTR_START_OFFSET, 5, 16,
int_to_bytes(operstate))
struct.pack_into("=LHHLL", data, 0, len(data), msg_type, 0, 0, 0)
return data
def test_media_down_up_scenario(self, m_read_netlink_socket,
m_socket):
'''Test for media down up sequence for required interface name'''
ifname = "eth0"
# construct data for Oper State down
data_op_down = self._media_switch_data(ifname, RTM_NEWLINK, OPER_DOWN)
# construct data for Oper State up
data_op_up = self._media_switch_data(ifname, RTM_NEWLINK, OPER_UP)
m_read_netlink_socket.side_effect = [data_op_down, data_op_up]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 2)
def test_wait_for_media_switch_diff_interface(self, m_read_netlink_socket,
m_socket):
'''wait_for_media_disconnect_connect ignores unexpected interfaces.
The first two messages are for other interfaces and last two are for
expected interface. So the function exit only after receiving last
2 messages and therefore the call count for m_read_netlink_socket
has to be 4
'''
other_ifname = "eth1"
expected_ifname = "eth0"
data_op_down_eth1 = self._media_switch_data(
other_ifname, RTM_NEWLINK, OPER_DOWN
)
data_op_up_eth1 = self._media_switch_data(
other_ifname, RTM_NEWLINK, OPER_UP
)
data_op_down_eth0 = self._media_switch_data(
expected_ifname, RTM_NEWLINK, OPER_DOWN
)
data_op_up_eth0 = self._media_switch_data(
expected_ifname, RTM_NEWLINK, OPER_UP)
m_read_netlink_socket.side_effect = [
data_op_down_eth1,
data_op_up_eth1,
data_op_down_eth0,
data_op_up_eth0
]
wait_for_media_disconnect_connect(m_socket, expected_ifname)
self.assertIn('Ignored netlink event on interface %s' % other_ifname,
self.logs.getvalue())
self.assertEqual(m_read_netlink_socket.call_count, 4)
def test_invalid_msgtype_getlink(self, m_read_netlink_socket, m_socket):
'''wait_for_media_disconnect_connect ignores GETLINK events.
The first two messages are for oper down and up for RTM_GETLINK type
which netlink module will ignore. The last 2 messages are RTM_NEWLINK
with oper state down and up messages. Therefore the call count for
m_read_netlink_socket has to be 4 ignoring first 2 messages
of RTM_GETLINK
'''
ifname = "eth0"
data_getlink_down = self._media_switch_data(
ifname, RTM_GETLINK, OPER_DOWN
)
data_getlink_up = self._media_switch_data(
ifname, RTM_GETLINK, OPER_UP
)
data_newlink_down = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_DOWN
)
data_newlink_up = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_UP
)
m_read_netlink_socket.side_effect = [
data_getlink_down,
data_getlink_up,
data_newlink_down,
data_newlink_up
]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 4)
def test_invalid_msgtype_setlink(self, m_read_netlink_socket, m_socket):
'''wait_for_media_disconnect_connect ignores SETLINK events.
The first two messages are for oper down and up for RTM_GETLINK type
which it will ignore. 3rd and 4th messages are RTM_NEWLINK with down
and up messages. This function should exit after 4th messages since it
sees down->up scenario. So the call count for m_read_netlink_socket
has to be 4 ignoring first 2 messages of RTM_GETLINK and
last 2 messages of RTM_NEWLINK
'''
ifname = "eth0"
data_setlink_down = self._media_switch_data(
ifname, RTM_SETLINK, OPER_DOWN
)
data_setlink_up = self._media_switch_data(
ifname, RTM_SETLINK, OPER_UP
)
data_newlink_down = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_DOWN
)
data_newlink_up = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_UP
)
m_read_netlink_socket.side_effect = [
data_setlink_down,
data_setlink_up,
data_newlink_down,
data_newlink_up,
data_newlink_down,
data_newlink_up
]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 4)
def test_netlink_invalid_switch_scenario(self, m_read_netlink_socket,
m_socket):
'''returns only if it receives UP event after a DOWN event'''
ifname = "eth0"
data_op_down = self._media_switch_data(ifname, RTM_NEWLINK, OPER_DOWN)
data_op_up = self._media_switch_data(ifname, RTM_NEWLINK, OPER_UP)
data_op_dormant = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_DORMANT
)
data_op_notpresent = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_NOTPRESENT
)
data_op_lowerdown = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_LOWERLAYERDOWN
)
data_op_testing = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_TESTING
)
data_op_unknown = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_UNKNOWN
)
m_read_netlink_socket.side_effect = [
data_op_up, data_op_up,
data_op_dormant, data_op_up,
data_op_notpresent, data_op_up,
data_op_lowerdown, data_op_up,
data_op_testing, data_op_up,
data_op_unknown, data_op_up,
data_op_down, data_op_up
]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 14)
def test_netlink_valid_inbetween_transitions(self, m_read_netlink_socket,
m_socket):
'''wait_for_media_disconnect_connect handles in between transitions'''
ifname = "eth0"
data_op_down = self._media_switch_data(ifname, RTM_NEWLINK, OPER_DOWN)
data_op_up = self._media_switch_data(ifname, RTM_NEWLINK, OPER_UP)
data_op_dormant = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_DORMANT)
data_op_unknown = self._media_switch_data(
ifname, RTM_NEWLINK, OPER_UNKNOWN)
m_read_netlink_socket.side_effect = [
data_op_down, data_op_dormant,
data_op_unknown, data_op_up
]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 4)
def test_netlink_invalid_operstate(self, m_read_netlink_socket, m_socket):
'''wait_for_media_disconnect_connect should handle invalid operstates.
The function should not fail and return even if it receives invalid
operstates. It always should wait for down up sequence.
'''
ifname = "eth0"
data_op_down = self._media_switch_data(ifname, RTM_NEWLINK, OPER_DOWN)
data_op_up = self._media_switch_data(ifname, RTM_NEWLINK, OPER_UP)
data_op_invalid = self._media_switch_data(ifname, RTM_NEWLINK, 7)
m_read_netlink_socket.side_effect = [
data_op_invalid, data_op_up,
data_op_down, data_op_invalid,
data_op_up
]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 5)
def test_wait_invalid_socket(self, m_read_netlink_socket, m_socket):
'''wait_for_media_disconnect_connect handle none netlink socket.'''
socket = None
ifname = "eth0"
with self.assertRaises(AssertionError) as context:
wait_for_media_disconnect_connect(socket, ifname)
self.assertTrue('netlink socket is none' in str(context.exception))
def test_wait_invalid_ifname(self, m_read_netlink_socket, m_socket):
'''wait_for_media_disconnect_connect handle none interface name'''
ifname = None
with self.assertRaises(AssertionError) as context:
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertTrue('interface name is none' in str(context.exception))
ifname = ""
with self.assertRaises(AssertionError) as context:
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertTrue('interface name cannot be empty' in
str(context.exception))
def test_wait_invalid_rta_attr(self, m_read_netlink_socket, m_socket):
''' wait_for_media_disconnect_connect handles invalid rta data'''
ifname = "eth0"
data_invalid1 = self._media_switch_data(None, RTM_NEWLINK, OPER_DOWN)
data_invalid2 = self._media_switch_data(ifname, RTM_NEWLINK, None)
data_op_down = self._media_switch_data(ifname, RTM_NEWLINK, OPER_DOWN)
data_op_up = self._media_switch_data(ifname, RTM_NEWLINK, OPER_UP)
m_read_netlink_socket.side_effect = [
data_invalid1, data_invalid2, data_op_down, data_op_up
]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 4)
def test_read_multiple_netlink_msgs(self, m_read_netlink_socket, m_socket):
'''Read multiple messages in single receive call'''
ifname = "eth0"
bytes = ifname.encode("utf-8")
data = bytearray(96)
struct.pack_into("=LHHLL", data, 0, 48, RTM_NEWLINK, 0, 0, 0)
struct.pack_into(
"HH4sHHc", data, RTATTR_START_OFFSET, 8, 3,
bytes, 5, 16, int_to_bytes(OPER_DOWN)
)
struct.pack_into("=LHHLL", data, 48, 48, RTM_NEWLINK, 0, 0, 0)
struct.pack_into(
"HH4sHHc", data, 48 + RTATTR_START_OFFSET, 8,
3, bytes, 5, 16, int_to_bytes(OPER_UP)
)
m_read_netlink_socket.return_value = data
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 1)
def test_read_partial_netlink_msgs(self, m_read_netlink_socket, m_socket):
'''Read partial messages in receive call'''
ifname = "eth0"
bytes = ifname.encode("utf-8")
data1 = bytearray(112)
data2 = bytearray(32)
struct.pack_into("=LHHLL", data1, 0, 48, RTM_NEWLINK, 0, 0, 0)
struct.pack_into(
"HH4sHHc", data1, RTATTR_START_OFFSET, 8, 3,
bytes, 5, 16, int_to_bytes(OPER_DOWN)
)
struct.pack_into("=LHHLL", data1, 48, 48, RTM_NEWLINK, 0, 0, 0)
struct.pack_into(
"HH4sHHc", data1, 80, 8, 3, bytes, 5, 16, int_to_bytes(OPER_DOWN)
)
struct.pack_into("=LHHLL", data1, 96, 48, RTM_NEWLINK, 0, 0, 0)
struct.pack_into(
"HH4sHHc", data2, 16, 8, 3, bytes, 5, 16, int_to_bytes(OPER_UP)
)
m_read_netlink_socket.side_effect = [data1, data2]
wait_for_media_disconnect_connect(m_socket, ifname)
self.assertEqual(m_read_netlink_socket.call_count, 2)