From bf7917159dbb292c9fcdef82b004e0f5ecb32c16 Mon Sep 17 00:00:00 2001 From: Tamilmani Manoharan Date: Thu, 29 Nov 2018 21:53:18 +0000 Subject: azure: detect vnet migration via netlink media change event Replace Azure pre-provision polling on IMDS with a blocking call which watches for netlink link state change messages. The media change event happens when a pre-provisioned VM has been activated and is connected to the users virtual network and cloud-init can then resume operation to complete image instantiation. --- cloudinit/sources/DataSourceAzure.py | 31 +- cloudinit/sources/helpers/netlink.py | 250 ++++++++++++++++ cloudinit/sources/helpers/tests/test_netlink.py | 373 ++++++++++++++++++++++++ 3 files changed, 650 insertions(+), 4 deletions(-) create mode 100644 cloudinit/sources/helpers/netlink.py create mode 100644 cloudinit/sources/helpers/tests/test_netlink.py (limited to 'cloudinit') diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py index be82ec4d..e076d5dc 100644 --- a/cloudinit/sources/DataSourceAzure.py +++ b/cloudinit/sources/DataSourceAzure.py @@ -22,6 +22,7 @@ from cloudinit.event import EventType from cloudinit.net.dhcp import EphemeralDHCPv4 from cloudinit import sources from cloudinit.sources.helpers.azure import get_metadata_from_fabric +from cloudinit.sources.helpers import netlink from cloudinit.url_helper import UrlError, readurl, retry_on_url_exc from cloudinit import util @@ -409,6 +410,10 @@ class DataSourceAzure(sources.DataSource): perform_reprovision = reprovision or self._should_reprovision(ret) if perform_reprovision: + if util.is_FreeBSD(): + msg = "Free BSD is not supported for PPS VMs" + LOG.error(msg) + raise sources.InvalidMetaDataException(msg) ret = self._reprovision() imds_md = get_metadata_from_imds( self.fallback_interface, retries=3) @@ -523,8 +528,8 @@ class DataSourceAzure(sources.DataSource): response. Then return the returned JSON object.""" url = IMDS_URL + "reprovisiondata?api-version=2017-04-02" headers = {"Metadata": "true"} + nl_sock = None report_ready = bool(not os.path.isfile(REPORTED_READY_MARKER_FILE)) - LOG.debug("Start polling IMDS") def exc_cb(msg, exception): if isinstance(exception, UrlError) and exception.code == 404: @@ -533,12 +538,19 @@ class DataSourceAzure(sources.DataSource): # call DHCP and setup the ephemeral network to acquire the new IP. return False + LOG.debug("Wait for vnetswitch to happen") while True: try: # Save our EphemeralDHCPv4 context so we avoid repeated dhcp self._ephemeral_dhcp_ctx = EphemeralDHCPv4() lease = self._ephemeral_dhcp_ctx.obtain_lease() if report_ready: + try: + nl_sock = netlink.create_bound_netlink_socket() + except netlink.NetlinkCreateSocketError as e: + LOG.warning(e) + self._ephemeral_dhcp_ctx.clean_network() + return path = REPORTED_READY_MARKER_FILE LOG.info( "Creating a marker file to report ready: %s", path) @@ -546,13 +558,24 @@ class DataSourceAzure(sources.DataSource): pid=os.getpid(), time=time())) self._report_ready(lease=lease) report_ready = False - return readurl(url, timeout=1, headers=headers, - exception_cb=exc_cb, infinite=True, - log_req_resp=False).contents + try: + netlink.wait_for_media_disconnect_connect( + nl_sock, lease['interface']) + except AssertionError as error: + LOG.error(error) + return + self._ephemeral_dhcp_ctx.clean_network() + else: + return readurl(url, timeout=1, headers=headers, + exception_cb=exc_cb, infinite=True, + log_req_resp=False).contents except UrlError: # Teardown our EphemeralDHCPv4 context on failure as we retry self._ephemeral_dhcp_ctx.clean_network() pass + finally: + if nl_sock: + nl_sock.close() def _report_ready(self, lease): """Tells the fabric provisioning has completed """ diff --git a/cloudinit/sources/helpers/netlink.py b/cloudinit/sources/helpers/netlink.py new file mode 100644 index 00000000..d377ae3d --- /dev/null +++ b/cloudinit/sources/helpers/netlink.py @@ -0,0 +1,250 @@ +# Author: Tamilmani Manoharan +# +# This file is part of cloud-init. See LICENSE file for license information. + +from cloudinit import log as logging +from cloudinit import util +from collections import namedtuple + +import os +import select +import socket +import struct + +LOG = logging.getLogger(__name__) + +# http://man7.org/linux/man-pages/man7/netlink.7.html +RTMGRP_LINK = 1 +NLMSG_NOOP = 1 +NLMSG_ERROR = 2 +NLMSG_DONE = 3 +RTM_NEWLINK = 16 +RTM_DELLINK = 17 +RTM_GETLINK = 18 +RTM_SETLINK = 19 +MAX_SIZE = 65535 +RTA_DATA_OFFSET = 32 +MSG_TYPE_OFFSET = 16 +SELECT_TIMEOUT = 60 + +NLMSGHDR_FMT = "IHHII" +IFINFOMSG_FMT = "BHiII" +NLMSGHDR_SIZE = struct.calcsize(NLMSGHDR_FMT) +IFINFOMSG_SIZE = struct.calcsize(IFINFOMSG_FMT) +RTATTR_START_OFFSET = NLMSGHDR_SIZE + IFINFOMSG_SIZE +RTA_DATA_START_OFFSET = 4 +PAD_ALIGNMENT = 4 + +IFLA_IFNAME = 3 +IFLA_OPERSTATE = 16 + +# https://www.kernel.org/doc/Documentation/networking/operstates.txt +OPER_UNKNOWN = 0 +OPER_NOTPRESENT = 1 +OPER_DOWN = 2 +OPER_LOWERLAYERDOWN = 3 +OPER_TESTING = 4 +OPER_DORMANT = 5 +OPER_UP = 6 + +RTAAttr = namedtuple('RTAAttr', ['length', 'rta_type', 'data']) +InterfaceOperstate = namedtuple('InterfaceOperstate', ['ifname', 'operstate']) +NetlinkHeader = namedtuple('NetlinkHeader', ['length', 'type', 'flags', 'seq', + 'pid']) + + +class NetlinkCreateSocketError(RuntimeError): + '''Raised if netlink socket fails during create or bind.''' + pass + + +def create_bound_netlink_socket(): + '''Creates netlink socket and bind on netlink group to catch interface + down/up events. The socket will bound only on RTMGRP_LINK (which only + includes RTM_NEWLINK/RTM_DELLINK/RTM_GETLINK events). The socket is set to + non-blocking mode since we're only receiving messages. + + :returns: netlink socket in non-blocking mode + :raises: NetlinkCreateSocketError + ''' + try: + netlink_socket = socket.socket(socket.AF_NETLINK, + socket.SOCK_RAW, + socket.NETLINK_ROUTE) + netlink_socket.bind((os.getpid(), RTMGRP_LINK)) + netlink_socket.setblocking(0) + except socket.error as e: + msg = "Exception during netlink socket create: %s" % e + raise NetlinkCreateSocketError(msg) + LOG.debug("Created netlink socket") + return netlink_socket + + +def get_netlink_msg_header(data): + '''Gets netlink message type and length + + :param: data read from netlink socket + :returns: netlink message type + :raises: AssertionError if data is None or data is not >= NLMSGHDR_SIZE + struct nlmsghdr { + __u32 nlmsg_len; /* Length of message including header */ + __u16 nlmsg_type; /* Type of message content */ + __u16 nlmsg_flags; /* Additional flags */ + __u32 nlmsg_seq; /* Sequence number */ + __u32 nlmsg_pid; /* Sender port ID */ + }; + ''' + assert (data is not None), ("data is none") + assert (len(data) >= NLMSGHDR_SIZE), ( + "data is smaller than netlink message header") + msg_len, msg_type, flags, seq, pid = struct.unpack(NLMSGHDR_FMT, + data[:MSG_TYPE_OFFSET]) + LOG.debug("Got netlink msg of type %d", msg_type) + return NetlinkHeader(msg_len, msg_type, flags, seq, pid) + + +def read_netlink_socket(netlink_socket, timeout=None): + '''Select and read from the netlink socket if ready. + + :param: netlink_socket: specify which socket object to read from + :param: timeout: specify a timeout value (integer) to wait while reading, + if none, it will block indefinitely until socket ready for read + :returns: string of data read (max length = ) from socket, + if no data read, returns None + :raises: AssertionError if netlink_socket is None + ''' + assert (netlink_socket is not None), ("netlink socket is none") + read_set, _, _ = select.select([netlink_socket], [], [], timeout) + # Incase of timeout,read_set doesn't contain netlink socket. + # just return from this function + if netlink_socket not in read_set: + return None + LOG.debug("netlink socket ready for read") + data = netlink_socket.recv(MAX_SIZE) + if data is None: + LOG.error("Reading from Netlink socket returned no data") + return data + + +def unpack_rta_attr(data, offset): + '''Unpack a single rta attribute. + + :param: data: string of data read from netlink socket + :param: offset: starting offset of RTA Attribute + :return: RTAAttr object with length, type and data. On error, return None. + :raises: AssertionError if data is None or offset is not integer. + ''' + assert (data is not None), ("data is none") + assert (type(offset) == int), ("offset is not integer") + assert (offset >= RTATTR_START_OFFSET), ( + "rta offset is less than expected length") + length = rta_type = 0 + attr_data = None + try: + length = struct.unpack_from("H", data, offset=offset)[0] + rta_type = struct.unpack_from("H", data, offset=offset+2)[0] + except struct.error: + return None # Should mean our offset is >= remaining data + + # Unpack just the attribute's data. Offset by 4 to skip length/type header + attr_data = data[offset+RTA_DATA_START_OFFSET:offset+length] + return RTAAttr(length, rta_type, attr_data) + + +def read_rta_oper_state(data): + '''Reads Interface name and operational state from RTA Data. + + :param: data: string of data read from netlink socket + :returns: InterfaceOperstate object containing if_name and oper_state. + None if data does not contain valid IFLA_OPERSTATE and + IFLA_IFNAME messages. + :raises: AssertionError if data is None or length of data is + smaller than RTATTR_START_OFFSET. + ''' + assert (data is not None), ("data is none") + assert (len(data) > RTATTR_START_OFFSET), ( + "length of data is smaller than RTATTR_START_OFFSET") + ifname = operstate = None + offset = RTATTR_START_OFFSET + while offset <= len(data): + attr = unpack_rta_attr(data, offset) + if not attr or attr.length == 0: + break + # Each attribute is 4-byte aligned. Determine pad length. + padlen = (PAD_ALIGNMENT - + (attr.length % PAD_ALIGNMENT)) % PAD_ALIGNMENT + offset += attr.length + padlen + + if attr.rta_type == IFLA_OPERSTATE: + operstate = ord(attr.data) + elif attr.rta_type == IFLA_IFNAME: + interface_name = util.decode_binary(attr.data, 'utf-8') + ifname = interface_name.strip('\0') + if not ifname or operstate is None: + return None + LOG.debug("rta attrs: ifname %s operstate %d", ifname, operstate) + return InterfaceOperstate(ifname, operstate) + + +def wait_for_media_disconnect_connect(netlink_socket, ifname): + '''Block until media disconnect and connect has happened on an interface. + Listens on netlink socket to receive netlink events and when the carrier + changes from 0 to 1, it considers event has happened and + return from this function + + :param: netlink_socket: netlink_socket to receive events + :param: ifname: Interface name to lookout for netlink events + :raises: AssertionError if netlink_socket is None or ifname is None. + ''' + assert (netlink_socket is not None), ("netlink socket is none") + assert (ifname is not None), ("interface name is none") + assert (len(ifname) > 0), ("interface name cannot be empty") + carrier = OPER_UP + prevCarrier = OPER_UP + data = bytes() + LOG.debug("Wait for media disconnect and reconnect to happen") + while True: + recv_data = read_netlink_socket(netlink_socket, SELECT_TIMEOUT) + if recv_data is None: + continue + LOG.debug('read %d bytes from socket', len(recv_data)) + data += recv_data + LOG.debug('Length of data after concat %d', len(data)) + offset = 0 + datalen = len(data) + while offset < datalen: + nl_msg = data[offset:] + if len(nl_msg) < NLMSGHDR_SIZE: + LOG.debug("Data is smaller than netlink header") + break + nlheader = get_netlink_msg_header(nl_msg) + if len(nl_msg) < nlheader.length: + LOG.debug("Partial data. Smaller than netlink message") + break + padlen = (nlheader.length+PAD_ALIGNMENT-1) & ~(PAD_ALIGNMENT-1) + offset = offset + padlen + LOG.debug('offset to next netlink message: %d', offset) + # Ignore any messages not new link or del link + if nlheader.type not in [RTM_NEWLINK, RTM_DELLINK]: + continue + interface_state = read_rta_oper_state(nl_msg) + if interface_state is None: + LOG.debug('Failed to read rta attributes: %s', interface_state) + continue + if interface_state.ifname != ifname: + LOG.debug( + "Ignored netlink event on interface %s. Waiting for %s.", + interface_state.ifname, ifname) + continue + if interface_state.operstate not in [OPER_UP, OPER_DOWN]: + continue + prevCarrier = carrier + carrier = interface_state.operstate + # check for carrier down, up sequence + isVnetSwitch = (prevCarrier == OPER_DOWN) and (carrier == OPER_UP) + if isVnetSwitch: + LOG.debug("Media switch happened on %s.", ifname) + return + data = data[offset:] + +# vi: ts=4 expandtab diff --git a/cloudinit/sources/helpers/tests/test_netlink.py b/cloudinit/sources/helpers/tests/test_netlink.py new file mode 100644 index 00000000..c2898a16 --- /dev/null +++ b/cloudinit/sources/helpers/tests/test_netlink.py @@ -0,0 +1,373 @@ +# Author: Tamilmani Manoharan +# +# 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.assertTrue('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) -- cgit v1.2.3