diff options
Diffstat (limited to 'cloudinit/sources/helpers')
-rw-r--r-- | cloudinit/sources/helpers/netlink.py | 102 | ||||
-rw-r--r-- | cloudinit/sources/helpers/tests/test_netlink.py | 74 |
2 files changed, 163 insertions, 13 deletions
diff --git a/cloudinit/sources/helpers/netlink.py b/cloudinit/sources/helpers/netlink.py index c2ad587b..e13d6834 100644 --- a/cloudinit/sources/helpers/netlink.py +++ b/cloudinit/sources/helpers/netlink.py @@ -185,6 +185,54 @@ def read_rta_oper_state(data): return InterfaceOperstate(ifname, operstate) +def wait_for_nic_attach_event(netlink_socket, existing_nics): + '''Block until a single nic is attached. + + :param: netlink_socket: netlink_socket to receive events + :param: existing_nics: List of existing nics so that we can skip them. + :raises: AssertionError if netlink_socket is none. + ''' + LOG.debug("Preparing to wait for nic attach.") + ifname = None + + def should_continue_cb(iname, carrier, prevCarrier): + if iname in existing_nics: + return True + nonlocal ifname + ifname = iname + return False + + # We can return even if the operational state of the new nic is DOWN + # because we set it to UP before doing dhcp. + read_netlink_messages(netlink_socket, + None, + [RTM_NEWLINK], + [OPER_UP, OPER_DOWN], + should_continue_cb) + return ifname + + +def wait_for_nic_detach_event(netlink_socket): + '''Block until a single nic is detached and its operational state is down. + + :param: netlink_socket: netlink_socket to receive events. + ''' + LOG.debug("Preparing to wait for nic detach.") + ifname = None + + def should_continue_cb(iname, carrier, prevCarrier): + nonlocal ifname + ifname = iname + return False + + read_netlink_messages(netlink_socket, + None, + [RTM_DELLINK], + [OPER_DOWN], + should_continue_cb) + return ifname + + 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 @@ -198,10 +246,42 @@ def wait_for_media_disconnect_connect(netlink_socket, ifname): 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") + + def should_continue_cb(iname, carrier, prevCarrier): + # 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 False + return True + + LOG.debug("Wait for media disconnect and reconnect to happen") + read_netlink_messages(netlink_socket, + ifname, + [RTM_NEWLINK, RTM_DELLINK], + [OPER_UP, OPER_DOWN], + should_continue_cb) + + +def read_netlink_messages(netlink_socket, + ifname_filter, + rtm_types, + operstates, + should_continue_callback): + ''' Reads from the netlink socket until the condition specified by + the continuation callback is met. + + :param: netlink_socket: netlink_socket to receive events. + :param: ifname_filter: if not None, will only listen for this interface. + :param: rtm_types: Type of netlink events to listen for. + :param: operstates: Operational states to listen. + :param: should_continue_callback: Specifies when to stop listening. + ''' + if netlink_socket is None: + raise RuntimeError("Netlink socket is none") + data = bytes() 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: @@ -223,26 +303,26 @@ def wait_for_media_disconnect_connect(netlink_socket, ifname): 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 if we are not interested in this message. + if nlheader.type not in rtm_types: 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: + if (ifname_filter is not None and + interface_state.ifname != ifname_filter): LOG.debug( "Ignored netlink event on interface %s. Waiting for %s.", - interface_state.ifname, ifname) + interface_state.ifname, ifname_filter) continue - if interface_state.operstate not in [OPER_UP, OPER_DOWN]: + if interface_state.operstate not in operstates: 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) + if not should_continue_callback(interface_state.ifname, + carrier, + prevCarrier): return data = data[offset:] diff --git a/cloudinit/sources/helpers/tests/test_netlink.py b/cloudinit/sources/helpers/tests/test_netlink.py index 10760bd6..cafe3961 100644 --- a/cloudinit/sources/helpers/tests/test_netlink.py +++ b/cloudinit/sources/helpers/tests/test_netlink.py @@ -9,9 +9,10 @@ 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, + wait_for_nic_attach_event, wait_for_nic_detach_event, 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) + OPER_TESTING, OPER_UNKNOWN, RTATTR_START_OFFSET, RTM_NEWLINK, RTM_DELLINK, + RTM_SETLINK, RTM_GETLINK, MAX_SIZE) def int_to_bytes(i): @@ -135,6 +136,75 @@ class TestParseNetlinkMessage(CiTestCase): @mock.patch('cloudinit.sources.helpers.netlink.socket.socket') @mock.patch('cloudinit.sources.helpers.netlink.read_netlink_socket') +class TestNicAttachDetach(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_nic_attached_oper_down(self, m_read_netlink_socket, m_socket): + '''Test for a new nic attached''' + ifname = "eth0" + data_op_down = self._media_switch_data(ifname, RTM_NEWLINK, OPER_DOWN) + m_read_netlink_socket.side_effect = [data_op_down] + ifread = wait_for_nic_attach_event(m_socket, []) + self.assertEqual(m_read_netlink_socket.call_count, 1) + self.assertEqual(ifname, ifread) + + def test_nic_attached_oper_up(self, m_read_netlink_socket, m_socket): + '''Test for a new nic attached''' + ifname = "eth0" + data_op_up = self._media_switch_data(ifname, RTM_NEWLINK, OPER_UP) + m_read_netlink_socket.side_effect = [data_op_up] + ifread = wait_for_nic_attach_event(m_socket, []) + self.assertEqual(m_read_netlink_socket.call_count, 1) + self.assertEqual(ifname, ifread) + + def test_nic_attach_ignore_existing(self, m_read_netlink_socket, m_socket): + '''Test that we read only the interfaces we are interested in.''' + data_eth0 = self._media_switch_data("eth0", RTM_NEWLINK, OPER_DOWN) + data_eth1 = self._media_switch_data("eth1", RTM_NEWLINK, OPER_DOWN) + m_read_netlink_socket.side_effect = [data_eth0, data_eth1] + ifread = wait_for_nic_attach_event(m_socket, ["eth0"]) + self.assertEqual(m_read_netlink_socket.call_count, 2) + self.assertEqual("eth1", ifread) + + def test_nic_attach_read_first(self, m_read_netlink_socket, m_socket): + '''Test that we read only the interfaces we are interested in.''' + data_eth0 = self._media_switch_data("eth0", RTM_NEWLINK, OPER_DOWN) + data_eth1 = self._media_switch_data("eth1", RTM_NEWLINK, OPER_DOWN) + m_read_netlink_socket.side_effect = [data_eth0, data_eth1] + ifread = wait_for_nic_attach_event(m_socket, ["eth1"]) + self.assertEqual(m_read_netlink_socket.call_count, 1) + self.assertEqual("eth0", ifread) + + def test_nic_detached(self, m_read_netlink_socket, m_socket): + '''Test for an existing nic detached''' + ifname = "eth0" + data_op_down = self._media_switch_data(ifname, RTM_DELLINK, OPER_DOWN) + m_read_netlink_socket.side_effect = [data_op_down] + ifread = wait_for_nic_detach_event(m_socket) + self.assertEqual(m_read_netlink_socket.call_count, 1) + self.assertEqual(ifname, ifread) + + +@mock.patch('cloudinit.sources.helpers.netlink.socket.socket') +@mock.patch('cloudinit.sources.helpers.netlink.read_netlink_socket') class TestWaitForMediaDisconnectConnect(CiTestCase): with_logs = True |