build.main.Main.execute() - Code Metrics - Inspection of "[Feature] Loop detection in the same switch via LL..." - kytos-ng/of_lldp - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#36)

by Vinicius

created 2022-04-04 20:07 UTC

build.main.Main.execute() D

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	76
Code Lines	58

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	37
CRAP Score	12.5799

Importance

Changes

Metric	Value
cc	12
eloc	58
nop	1
dl	0
loc	76
ccs	37
cts	44
cp	0.8409
crap	12.5799
rs	4.7345
c	0
b	0
f	0

How to fix Long Method Complexity

"""NApp responsible to discover new switches and hosts."""
import struct
import time

import requests
from flask import jsonify, request
from pyof.foundation.basic_types import DPID, UBInt16, UBInt32
from pyof.foundation.network_types import LLDP, VLAN, Ethernet, EtherType
from pyof.v0x01.common.action import ActionOutput as AO10
from pyof.v0x01.common.phy_port import Port as Port10
from pyof.v0x01.controller2switch.packet_out import PacketOut as PO10
from pyof.v0x04.common.action import ActionOutput as AO13
from pyof.v0x04.common.port import PortNo as Port13
from pyof.v0x04.controller2switch.packet_out import PacketOut as PO13

from kytos.core import KytosEvent, KytosNApp, log, rest
from kytos.core.helpers import listen_to
from napps.kytos.of_lldp import constants, settings
from napps.kytos.of_lldp.loop_manager import LoopManager, LoopState
from napps.kytos.of_lldp.utils import get_cookie


class Main(KytosNApp):
    """Main OF_LLDP NApp Class."""

    def setup(self):
        """Make this NApp run in a loop."""
        self.vlan_id = None
        self.polling_time = settings.POLLING_TIME
        if hasattr(settings, "FLOW_VLAN_VID"):
            self.vlan_id = settings.FLOW_VLAN_VID
        self.execute_as_loop(self.polling_time)
        self.loop_manager = LoopManager(self.controller)

    def execute(self):
        """Send LLDP Packets every 'POLLING_TIME' seconds to all switches."""
        switches = list(self.controller.switches.values())
        for switch in switches:
            try:
                of_version = switch.connection.protocol.version
            except AttributeError:
                of_version = None

            if not switch.is_connected():
                continue

            if of_version == 0x01:
                port_type = UBInt16
                local_port = Port10.OFPP_LOCAL
            elif of_version == 0x04:
                port_type = UBInt32
                local_port = Port13.OFPP_LOCAL
            else:
                # skip the current switch with unsupported OF version
                continue

            interfaces = list(switch.interfaces.values())
            for interface in interfaces:
                # Interface marked to receive lldp packet
                # Only send LLDP packet to active interface
                if(not interface.lldp or not interface.is_active()
                   or not interface.is_enabled()):
                    continue
                # Avoid the interface that connects to the controller.
                if interface.port_number == local_port:
                    continue

                lldp = LLDP()
                lldp.chassis_id.sub_value = DPID(switch.dpid)
                lldp.port_id.sub_value = port_type(interface.port_number)

                ethernet = Ethernet()
                ethernet.ether_type = EtherType.LLDP
                ethernet.source = interface.address
                ethernet.destination = constants.LLDP_MULTICAST_MAC
                ethernet.data = lldp.pack()
                # self.vlan_id == None will result in a packet with no VLAN.
                ethernet.vlans.append(VLAN(vid=self.vlan_id))

                packet_out = self._build_lldp_packet_out(
                                    of_version,
                                    interface.port_number, ethernet.pack())

                if packet_out is None:
                    continue

                event_out = KytosEvent(
                    name='kytos/of_lldp.messages.out.ofpt_packet_out',
                    content={
                            'destination': switch.connection,
                            'message': packet_out})
                self.controller.buffers.msg_out.put(event_out)
                log.debug(
                    "Sending a LLDP PacketOut to the switch %s",
                    switch.dpid)

                msg = 'Switch: %s (%s)'
                msg += ' Interface: %s'
                msg += ' -- LLDP PacketOut --'
                msg += ' Ethernet: eth_type (%s) | src (%s) | dst (%s) /'
                msg += ' LLDP: Switch (%s) | portno (%s)'

                log.debug(
                    msg,
                    switch.connection, switch.dpid,
                    interface.id, ethernet.ether_type,
                    ethernet.source, ethernet.destination,
                    switch.dpid, interface.port_number)

        self.try_to_publish_stopped_loops()

    def try_to_publish_stopped_loops(self):
        """Try to publish current stopped loops."""
        for dpid, port_pairs in self.loop_manager.get_stopped_loops().items():
            try:
                switch = self.controller.get_switch_by_dpid(dpid)
                for port_pair in port_pairs:
                    interface_a = switch.interfaces[port_pair[0]]
                    interface_b = switch.interfaces[port_pair[1]]
                    self.loop_manager.publish_loop_state(
                        interface_a, interface_b, LoopState.stopped.value
                    )
            except (KeyError, AttributeError) as exc:
                items = self.loop_manager.get_stopped_loops()
                log.error(f"try_to_publish_stopped_loops failed with: {items} "
                          f"{str(exc)}")
                return None

    @listen_to('kytos/topology.switch.(enabled|disabled)')
    def handle_lldp_flows(self, event):
        """Install or remove flows in a switch.

        Install a flow to send LLDP packets to the controller. The proactive
        flow is installed whenever a switch is enabled. If the switch is
        disabled the flow is removed.

        Args:
            event (:class:`~kytos.core.events.KytosEvent`):
                Event with new switch information.

        """
        self._handle_lldp_flows(event)

    @listen_to("kytos/of_lldp.loop.action.log")
    def on_lldp_loop_log_action(self, event):
        """Handle LLDP loop log action."""
        interface_a = event.content["interface_a"]
        interface_b = event.content["interface_b"]
        self.loop_manager.handle_log_action(interface_a, interface_b)

    @listen_to("kytos/of_lldp.loop.action.disable")
    def on_lldp_loop_disable_action(self, event):
        """Handle LLDP loop disable action."""
        interface_a = event.content["interface_a"]
        interface_b = event.content["interface_b"]
        self.loop_manager.handle_disable_action(interface_a, interface_b)

    @listen_to("kytos/of_lldp.loop.detected")
    def on_lldp_loop_detected(self, event):
        """Handle LLDP loop detected."""
        interface_id = event.content["interface_id"]
        dpid = event.content["dpid"]
        port_pair = event.content["port_numbers"]
        self.loop_manager.handle_loop_detected(interface_id, dpid, port_pair)

    @listen_to("kytos/of_lldp.loop.stopped")
    def on_lldp_loop_stopped(self, event):
        """Handle LLDP loop stopped."""
        dpid = event.content["dpid"]
        port_pair = event.content["port_numbers"]
        try:
            switch = self.controller.get_switch_by_dpid(dpid)
            interface_a = switch.interfaces[port_pair[0]]
            interface_b = switch.interfaces[port_pair[1]]
            self.loop_manager.handle_loop_stopped(interface_a, interface_b)
        except (KeyError, AttributeError) as exc:
            log.error("on_lldp_loop_stopped failed with: "
                      f"{event.content} {str(exc)}")

    @listen_to("kytos/topology.topology_loaded")
    def on_topology_loaded(self, event):
        """Handle on topology loaded."""
        topology = event.content["topology"]
        self.loop_manager.handle_topology_loaded(topology)

    @listen_to("kytos/topology.switches.metadata.(added|removed)")
    def on_switches_metadata_changed(self, event):
        """Handle on switches metadata changed."""
        switch = event.content["switch"]
        self.loop_manager.handle_switch_metadata_changed(switch)

    def _handle_lldp_flows(self, event):
        """Install or remove flows in a switch.

        Install a flow to send LLDP packets to the controller. The proactive
        flow is installed whenever a switch is enabled. If the switch is
        disabled the flow is removed.
        """
        try:
            dpid = event.content['dpid']
            switch = self.controller.get_switch_by_dpid(dpid)
            of_version = switch.connection.protocol.version

        except AttributeError:
            of_version = None

        def _retry_if_status_code(response, endpoint, data, status_codes,
                                  retries=3, wait=2):
            """Retry if the response is in the status_codes."""
            if response.status_code not in status_codes:
                return
            if retries - 1 <= 0:
                return
            data = dict(data)
            data["force"] = True
            res = requests.post(endpoint, json=data)
            method = res.request.method
            if res.status_code != 202:
                log.error(f"Failed to retry on {endpoint}, error: {res.text},"
                          f" status: {res.status_code}, method: {method},"
                          f" data: {data}")
                time.sleep(wait)
                return _retry_if_status_code(response, endpoint, data,
                                             status_codes, retries - 1, wait)
            log.info(f"Successfully forced {method} flows to {endpoint}")

        flow = self._build_lldp_flow(of_version, get_cookie(switch.dpid))
        if flow:
            destination = switch.id
            endpoint = f'{settings.FLOW_MANAGER_URL}/flows/{destination}'
            data = {'flows': [flow]}
            if event.name == 'kytos/topology.switch.enabled':
                flow.pop("cookie_mask")
                res = requests.post(endpoint, json=data)
                if res.status_code != 202:
                    log.error(f"Failed to push flows on {destination},"
                              f" error: {res.text}, status: {res.status_code},"
                              f" data: {data}")
                _retry_if_status_code(res, endpoint, data, [424, 500])
            else:
                res = requests.delete(endpoint, json=data)
                if res.status_code != 202:
                    log.error(f"Failed to delete flows on {destination},"
                              f" error: {res.text}, status: {res.status_code}",
                              f" data: {data}")
                _retry_if_status_code(res, endpoint, data, [424, 500])

    @listen_to('kytos/of_core.v0x0[14].messages.in.ofpt_packet_in')
    def on_ofpt_packet_in(self, event):
        """Dispatch two KytosEvents to notify identified NNI interfaces.

        Args:
            event (:class:`~kytos.core.events.KytosEvent`):
                Event with an LLDP packet as data.

        """
        self.notify_uplink_detected(event)

    def notify_uplink_detected(self, event):
        """Dispatch two KytosEvents to notify identified NNI interfaces.

        Args:
            event (:class:`~kytos.core.events.KytosEvent`):
                Event with an LLDP packet as data.

        """
        ethernet = self._unpack_non_empty(Ethernet, event.message.data)
        if ethernet.ether_type == EtherType.LLDP:
            try:
                lldp = self._unpack_non_empty(LLDP, ethernet.data)
                dpid = self._unpack_non_empty(DPID, lldp.chassis_id.sub_value)
            except struct.error:
                #: If we have a LLDP packet but we cannot unpack it, or the
                #: unpacked packet does not contain the dpid attribute, then
                #: we are dealing with a LLDP generated by someone else. Thus
                #: this packet is not useful for us and we may just ignore it.
                return

            switch_a = event.source.switch
            port_a = event.message.in_port
            switch_b = None
            port_b = None

            # in_port is currently a UBInt16 in v0x01 and an Int in v0x04.
            if isinstance(port_a, int):
                port_a = UBInt32(port_a)

            try:
                switch_b = self.controller.get_switch_by_dpid(dpid.value)
                of_version = switch_b.connection.protocol.version
                port_type = UBInt16 if of_version == 0x01 else UBInt32
                port_b = self._unpack_non_empty(port_type,
                                                lldp.port_id.sub_value)
            except AttributeError:
                log.debug("Couldn't find datapath %s.", dpid.value)

            # Return if any of the needed information are not available
            if not (switch_a and port_a and switch_b and port_b):
                return

            interface_a = switch_a.get_interface_by_port_no(port_a.value)
            interface_b = switch_b.get_interface_by_port_no(port_b.value)

            self.loop_manager.process_if_looped(interface_a, interface_b)
            event_out = KytosEvent(name='kytos/of_lldp.interface.is.nni',
                                   content={'interface_a': interface_a,
                                            'interface_b': interface_b})
            self.controller.buffers.app.put(event_out)

    def notify_lldp_change(self, state, interface_ids):
        """Dispatch a KytosEvent to notify changes to the LLDP status."""
        content = {'attribute': 'LLDP',
                   'state': state,
                   'interface_ids': interface_ids}
        event_out = KytosEvent(name='kytos/of_lldp.network_status.updated',
                               content=content)
        self.controller.buffers.app.put(event_out)

    def shutdown(self):
        """End of the application."""
        log.debug('Shutting down...')

    @staticmethod
    def _build_lldp_packet_out(version, port_number, data):
        """Build a LLDP PacketOut message.

        Args:
            version (int): OpenFlow version
            port_number (int): Switch port number where the packet must be
                forwarded to.
            data (bytes): Binary data to be sent through the port.

        Returns:
            PacketOut message for the specific given OpenFlow version, if it
                is supported.
            None if the OpenFlow version is not supported.

        """
        if version == 0x01:
            action_output_class = AO10
            packet_out_class = PO10
        elif version == 0x04:
            action_output_class = AO13
            packet_out_class = PO13
        else:
            log.info('Openflow version %s is not yet supported.', version)
            return None

        output_action = action_output_class()
        output_action.port = port_number

        packet_out = packet_out_class()
        packet_out.data = data
        packet_out.actions.append(output_action)

        return packet_out

    def _build_lldp_flow(self, version, cookie,
                         cookie_mask=0xffffffffffffffff):
        """Build a Flow message to send LLDP to the controller.

        Args:
            version (int): OpenFlow version.

        Returns:
            Flow dictionary message for the specific given OpenFlow version,
            if it is supported.
            None if the OpenFlow version is not supported.

        """
        flow = {}
        match = {}
        flow['priority'] = settings.FLOW_PRIORITY
        flow['table_id'] = settings.TABLE_ID
        flow['cookie'] = cookie
        flow['cookie_mask'] = cookie_mask
        match['dl_type'] = EtherType.LLDP
        if self.vlan_id:
            match['dl_vlan'] = self.vlan_id
        flow['match'] = match

        if version == 0x01:
            flow['actions'] = [{'action_type': 'output',
                                'port': Port10.OFPP_CONTROLLER}]
        elif version == 0x04:
            flow['actions'] = [{'action_type': 'output',
                                'port': Port13.OFPP_CONTROLLER}]
        else:
            flow = None

        return flow

    @staticmethod
    def _unpack_non_empty(desired_class, data):
        """Unpack data using an instance of desired_class.

        Args:
            desired_class (class): The class to be used to unpack data.
            data (bytes): bytes to be unpacked.

        Return:
            An instance of desired_class class with data unpacked into it.

        Raises:
            UnpackException if the unpack could not be performed.

        """
        obj = desired_class()

        if hasattr(data, 'value'):
            data = data.value

        obj.unpack(data)

        return obj

    @staticmethod
    def _get_data(req):
        """Get request data."""
        data = req.get_json()  # Valid format { "interfaces": [...] }
        return data.get('interfaces', [])

    def _get_interfaces(self):
        """Get all interfaces."""
        interfaces = []
        for switch in list(self.controller.switches.values()):
            interfaces += list(switch.interfaces.values())
        return interfaces

    @staticmethod
    def _get_interfaces_dict(interfaces):
        """Return a dict of interfaces."""
        return {inter.id: inter for inter in interfaces}

    def _get_lldp_interfaces(self):
        """Get interfaces enabled to receive LLDP packets."""
        return [inter.id for inter in self._get_interfaces() if inter.lldp]

    @rest('v1/interfaces', methods=['GET'])
    def get_lldp_interfaces(self):
        """Return all the interfaces that have LLDP traffic enabled."""
        return jsonify({"interfaces": self._get_lldp_interfaces()}), 200

    @rest('v1/interfaces/disable', methods=['POST'])

    def disable_lldp(self):
        """Disables an interface to receive LLDP packets."""
        interface_ids = self._get_data(request)
        error_list = []  # List of interfaces that were not activated.
        changed_interfaces = []
        interface_ids = filter(None, interface_ids)
        interfaces = self._get_interfaces()
        if not interfaces:
            return jsonify("No interfaces were found."), 404
        interfaces = self._get_interfaces_dict(interfaces)
        for id_ in interface_ids:
            interface = interfaces.get(id_)
            if interface:
                interface.lldp = False
                changed_interfaces.append(id_)
            else:
                error_list.append(id_)
        if changed_interfaces:
            self.notify_lldp_change('disabled', changed_interfaces)
        if not error_list:
            return jsonify(
                "All the requested interfaces have been disabled."), 200

        # Return a list of interfaces that couldn't be disabled
        msg_error = "Some interfaces couldn't be found and deactivated: "
        return jsonify({msg_error:
                        error_list}), 400

    @rest('v1/interfaces/enable', methods=['POST'])

    def enable_lldp(self):
        """Enable an interface to receive LLDP packets."""
        interface_ids = self._get_data(request)
        error_list = []  # List of interfaces that were not activated.
        changed_interfaces = []
        interface_ids = filter(None, interface_ids)
        interfaces = self._get_interfaces()
        if not interfaces:
            return jsonify("No interfaces were found."), 404
        interfaces = self._get_interfaces_dict(interfaces)
        for id_ in interface_ids:
            interface = interfaces.get(id_)
            if interface:
                interface.lldp = True
                changed_interfaces.append(id_)
            else:
                error_list.append(id_)
        if changed_interfaces:
            self.notify_lldp_change('enabled', changed_interfaces)
        if not error_list:
            return jsonify(
                "All the requested interfaces have been enabled."), 200

        # Return a list of interfaces that couldn't be enabled
        msg_error = "Some interfaces couldn't be found and activated: "
        return jsonify({msg_error:
                        error_list}), 400

    @rest('v1/polling_time', methods=['GET'])
    def get_time(self):
        """Get LLDP polling time in seconds."""
        return jsonify({"polling_time": self.polling_time}), 200

    @rest('v1/polling_time', methods=['POST'])
    def set_time(self):
        """Set LLDP polling time."""
        # pylint: disable=attribute-defined-outside-init
        try:
            payload = request.get_json()
            polling_time = int(payload['polling_time'])
            if polling_time <= 0:
                raise ValueError(f"invalid polling_time {polling_time}, "
                                 "must be greater than zero")
            self.polling_time = polling_time
            self.execute_as_loop(self.polling_time)
            log.info("Polling time has been updated to %s"
                     " second(s), but this change will not be saved"
                     " permanently.", self.polling_time)
            return jsonify("Polling time has been updated."), 200
        except (ValueError, KeyError) as error:
            msg = f"This operation is not completed: {error}"
            return jsonify(msg), 400


1			"""NApp responsible to discover new switches and hosts."""
2	1		import struct
3	1		import time
4
5	1		import requests
6	1		from flask import jsonify, request
7	1		from pyof.foundation.basic_types import DPID, UBInt16, UBInt32
8	1		from pyof.foundation.network_types import LLDP, VLAN, Ethernet, EtherType
9	1		from pyof.v0x01.common.action import ActionOutput as AO10
10	1		from pyof.v0x01.common.phy_port import Port as Port10
11	1		from pyof.v0x01.controller2switch.packet_out import PacketOut as PO10
12	1		from pyof.v0x04.common.action import ActionOutput as AO13
13	1		from pyof.v0x04.common.port import PortNo as Port13
14	1		from pyof.v0x04.controller2switch.packet_out import PacketOut as PO13
15
16	1		from kytos.core import KytosEvent, KytosNApp, log, rest
17	1		from kytos.core.helpers import listen_to
18	1		from napps.kytos.of_lldp import constants, settings
19	1		from napps.kytos.of_lldp.loop_manager import LoopManager, LoopState
20	1		from napps.kytos.of_lldp.utils import get_cookie
21
22
23	1		class Main(KytosNApp):
24			"""Main OF_LLDP NApp Class."""
25
26	1		def setup(self):
27			"""Make this NApp run in a loop."""
28	1		self.vlan_id = None
29	1		self.polling_time = settings.POLLING_TIME
30	1		if hasattr(settings, "FLOW_VLAN_VID"):
31	1		self.vlan_id = settings.FLOW_VLAN_VID
32	1		self.execute_as_loop(self.polling_time)
33	1		self.loop_manager = LoopManager(self.controller)
34
35	1		def execute(self):
36			"""Send LLDP Packets every 'POLLING_TIME' seconds to all switches."""
37	1		switches = list(self.controller.switches.values())
38	1		for switch in switches:
39	1		try:
40	1		of_version = switch.connection.protocol.version
41			except AttributeError:
42			of_version = None
43
44	1		if not switch.is_connected():
45			continue
46
47	1		if of_version == 0x01:
48	1		port_type = UBInt16
49	1		local_port = Port10.OFPP_LOCAL
50	1		elif of_version == 0x04:
51	1		port_type = UBInt32
52	1		local_port = Port13.OFPP_LOCAL
53			else:
54			# skip the current switch with unsupported OF version
55			continue
56
57	1		interfaces = list(switch.interfaces.values())
58	1		for interface in interfaces:
59			# Interface marked to receive lldp packet
60			# Only send LLDP packet to active interface
61	1		if(not interface.lldp or not interface.is_active()
62			or not interface.is_enabled()):
63			continue
64			# Avoid the interface that connects to the controller.
65	1		if interface.port_number == local_port:
66			continue
67
68	1		lldp = LLDP()
69	1		lldp.chassis_id.sub_value = DPID(switch.dpid)
70	1		lldp.port_id.sub_value = port_type(interface.port_number)
71
72	1		ethernet = Ethernet()
73	1		ethernet.ether_type = EtherType.LLDP
74	1		ethernet.source = interface.address
75	1		ethernet.destination = constants.LLDP_MULTICAST_MAC
76	1		ethernet.data = lldp.pack()
77			# self.vlan_id == None will result in a packet with no VLAN.
78	1		ethernet.vlans.append(VLAN(vid=self.vlan_id))
79
80	1		packet_out = self._build_lldp_packet_out(
81			of_version,
82			interface.port_number, ethernet.pack())
83
84	1		if packet_out is None:
85			continue
86
87	1		event_out = KytosEvent(
88			name='kytos/of_lldp.messages.out.ofpt_packet_out',
89			content={
90			'destination': switch.connection,
91			'message': packet_out})
92	1		self.controller.buffers.msg_out.put(event_out)
93	1		log.debug(
94			"Sending a LLDP PacketOut to the switch %s",
95			switch.dpid)
96
97	1		msg = 'Switch: %s (%s)'
98	1		msg += ' Interface: %s'
99	1		msg += ' -- LLDP PacketOut --'
100	1		msg += ' Ethernet: eth_type (%s) \| src (%s) \| dst (%s) /'
101	1		msg += ' LLDP: Switch (%s) \| portno (%s)'
102
103	1		log.debug(
104			msg,
105			switch.connection, switch.dpid,
106			interface.id, ethernet.ether_type,
107			ethernet.source, ethernet.destination,
108			switch.dpid, interface.port_number)
109
110	1		self.try_to_publish_stopped_loops()
111
112	1		def try_to_publish_stopped_loops(self):
113			"""Try to publish current stopped loops."""
114			for dpid, port_pairs in self.loop_manager.get_stopped_loops().items():
115			try:
116			switch = self.controller.get_switch_by_dpid(dpid)
117			for port_pair in port_pairs:
118			interface_a = switch.interfaces[port_pair[0]]
119			interface_b = switch.interfaces[port_pair[1]]
120			self.loop_manager.publish_loop_state(
121			interface_a, interface_b, LoopState.stopped.value
122			)
123			except (KeyError, AttributeError) as exc:
124			items = self.loop_manager.get_stopped_loops()
125			log.error(f"try_to_publish_stopped_loops failed with: {items} "
126			f"{str(exc)}")
127			return None
128
129	1		@listen_to('kytos/topology.switch.(enabled\|disabled)')
130			def handle_lldp_flows(self, event):
131			"""Install or remove flows in a switch.
132
133			Install a flow to send LLDP packets to the controller. The proactive
134			flow is installed whenever a switch is enabled. If the switch is
135			disabled the flow is removed.
136
137			Args:
138			event (:class:`~kytos.core.events.KytosEvent`):
139			Event with new switch information.
140
141			"""
142	1		self._handle_lldp_flows(event)
143
144	1		@listen_to("kytos/of_lldp.loop.action.log")
145			def on_lldp_loop_log_action(self, event):
146			"""Handle LLDP loop log action."""
147			interface_a = event.content["interface_a"]
148			interface_b = event.content["interface_b"]
149			self.loop_manager.handle_log_action(interface_a, interface_b)
150
151	1		@listen_to("kytos/of_lldp.loop.action.disable")
152			def on_lldp_loop_disable_action(self, event):
153			"""Handle LLDP loop disable action."""
154			interface_a = event.content["interface_a"]
155			interface_b = event.content["interface_b"]
156			self.loop_manager.handle_disable_action(interface_a, interface_b)
157
158	1		@listen_to("kytos/of_lldp.loop.detected")
159			def on_lldp_loop_detected(self, event):
160			"""Handle LLDP loop detected."""
161			interface_id = event.content["interface_id"]
162			dpid = event.content["dpid"]
163			port_pair = event.content["port_numbers"]
164			self.loop_manager.handle_loop_detected(interface_id, dpid, port_pair)
165
166	1		@listen_to("kytos/of_lldp.loop.stopped")
167			def on_lldp_loop_stopped(self, event):
168			"""Handle LLDP loop stopped."""
169			dpid = event.content["dpid"]
170			port_pair = event.content["port_numbers"]
171			try:
172			switch = self.controller.get_switch_by_dpid(dpid)
173			interface_a = switch.interfaces[port_pair[0]]
174			interface_b = switch.interfaces[port_pair[1]]
175			self.loop_manager.handle_loop_stopped(interface_a, interface_b)
176			except (KeyError, AttributeError) as exc:
177			log.error("on_lldp_loop_stopped failed with: "
178			f"{event.content} {str(exc)}")
179
180	1		@listen_to("kytos/topology.topology_loaded")
181			def on_topology_loaded(self, event):
182			"""Handle on topology loaded."""
183			topology = event.content["topology"]
184			self.loop_manager.handle_topology_loaded(topology)
185
186	1		@listen_to("kytos/topology.switches.metadata.(added\|removed)")
187			def on_switches_metadata_changed(self, event):
188			"""Handle on switches metadata changed."""
189			switch = event.content["switch"]
190			self.loop_manager.handle_switch_metadata_changed(switch)
191
192	1		def _handle_lldp_flows(self, event):
193			"""Install or remove flows in a switch.
194
195			Install a flow to send LLDP packets to the controller. The proactive
196			flow is installed whenever a switch is enabled. If the switch is
197			disabled the flow is removed.
198			"""
199	1		try:
200	1		dpid = event.content['dpid']
201	1		switch = self.controller.get_switch_by_dpid(dpid)
202	1		of_version = switch.connection.protocol.version
203
204			except AttributeError:
205			of_version = None
206
207	1		def _retry_if_status_code(response, endpoint, data, status_codes,
208			retries=3, wait=2):
209			"""Retry if the response is in the status_codes."""
210	1		if response.status_code not in status_codes:
211	1		return
212	1		if retries - 1 <= 0:
213	1		return
214	1		data = dict(data)
215	1		data["force"] = True
216	1		res = requests.post(endpoint, json=data)
217	1		method = res.request.method
218	1		if res.status_code != 202:
219	1		log.error(f"Failed to retry on {endpoint}, error: {res.text},"
220			f" status: {res.status_code}, method: {method},"
221			f" data: {data}")
222	1		time.sleep(wait)
223	1		return _retry_if_status_code(response, endpoint, data,
224			status_codes, retries - 1, wait)
225			log.info(f"Successfully forced {method} flows to {endpoint}")
226
227	1		flow = self._build_lldp_flow(of_version, get_cookie(switch.dpid))
228	1		if flow:
229	1		destination = switch.id
230	1		endpoint = f'{settings.FLOW_MANAGER_URL}/flows/{destination}'
231	1		data = {'flows': [flow]}
232	1		if event.name == 'kytos/topology.switch.enabled':
233	1		flow.pop("cookie_mask")
234	1		res = requests.post(endpoint, json=data)
235	1		if res.status_code != 202:
236	1		log.error(f"Failed to push flows on {destination},"
237			f" error: {res.text}, status: {res.status_code},"
238			f" data: {data}")
239	1		_retry_if_status_code(res, endpoint, data, [424, 500])
240			else:
241	1		res = requests.delete(endpoint, json=data)
242	1		if res.status_code != 202:
243	1		log.error(f"Failed to delete flows on {destination},"
244			f" error: {res.text}, status: {res.status_code}",
245			f" data: {data}")
246			_retry_if_status_code(res, endpoint, data, [424, 500])
247
248	1		@listen_to('kytos/of_core.v0x0[14].messages.in.ofpt_packet_in')
249			def on_ofpt_packet_in(self, event):
250			"""Dispatch two KytosEvents to notify identified NNI interfaces.
251
252			Args:
253			event (:class:`~kytos.core.events.KytosEvent`):
254			Event with an LLDP packet as data.
255
256			"""
257			self.notify_uplink_detected(event)
258
259	1		def notify_uplink_detected(self, event):
260			"""Dispatch two KytosEvents to notify identified NNI interfaces.
261
262			Args:
263			event (:class:`~kytos.core.events.KytosEvent`):
264			Event with an LLDP packet as data.
265
266			"""
267	1		ethernet = self._unpack_non_empty(Ethernet, event.message.data)
268	1		if ethernet.ether_type == EtherType.LLDP:
269	1		try:
270	1		lldp = self._unpack_non_empty(LLDP, ethernet.data)
271	1		dpid = self._unpack_non_empty(DPID, lldp.chassis_id.sub_value)
272			except struct.error:
273			#: If we have a LLDP packet but we cannot unpack it, or the
274			#: unpacked packet does not contain the dpid attribute, then
275			#: we are dealing with a LLDP generated by someone else. Thus
276			#: this packet is not useful for us and we may just ignore it.
277			return
278
279	1		switch_a = event.source.switch
280	1		port_a = event.message.in_port
281	1		switch_b = None
282	1		port_b = None
283
284			# in_port is currently a UBInt16 in v0x01 and an Int in v0x04.
285	1		if isinstance(port_a, int):
286	1		port_a = UBInt32(port_a)
287
288	1		try:
289	1		switch_b = self.controller.get_switch_by_dpid(dpid.value)
290	1		of_version = switch_b.connection.protocol.version
291	1		port_type = UBInt16 if of_version == 0x01 else UBInt32
292	1		port_b = self._unpack_non_empty(port_type,
293			lldp.port_id.sub_value)
294			except AttributeError:
295			log.debug("Couldn't find datapath %s.", dpid.value)
296
297			# Return if any of the needed information are not available
298	1		if not (switch_a and port_a and switch_b and port_b):
299			return
300
301	1		interface_a = switch_a.get_interface_by_port_no(port_a.value)
302	1		interface_b = switch_b.get_interface_by_port_no(port_b.value)
303
304	1		self.loop_manager.process_if_looped(interface_a, interface_b)
305	1		event_out = KytosEvent(name='kytos/of_lldp.interface.is.nni',
306			content={'interface_a': interface_a,
307			'interface_b': interface_b})
308	1		self.controller.buffers.app.put(event_out)
309
310	1		def notify_lldp_change(self, state, interface_ids):
311			"""Dispatch a KytosEvent to notify changes to the LLDP status."""
312	1		content = {'attribute': 'LLDP',
313			'state': state,
314			'interface_ids': interface_ids}
315	1		event_out = KytosEvent(name='kytos/of_lldp.network_status.updated',
316			content=content)
317	1		self.controller.buffers.app.put(event_out)
318
319	1		def shutdown(self):
320			"""End of the application."""
321			log.debug('Shutting down...')
322
323	1		@staticmethod
324			def _build_lldp_packet_out(version, port_number, data):
325			"""Build a LLDP PacketOut message.
326
327			Args:
328			version (int): OpenFlow version
329			port_number (int): Switch port number where the packet must be
330			forwarded to.
331			data (bytes): Binary data to be sent through the port.
332
333			Returns:
334			PacketOut message for the specific given OpenFlow version, if it
335			is supported.
336			None if the OpenFlow version is not supported.
337
338			"""
339	1		if version == 0x01:
340	1		action_output_class = AO10
341	1		packet_out_class = PO10
342	1		elif version == 0x04:
343	1		action_output_class = AO13
344	1		packet_out_class = PO13
345			else:
346	1		log.info('Openflow version %s is not yet supported.', version)
347	1		return None
348
349	1		output_action = action_output_class()
350	1		output_action.port = port_number
351
352	1		packet_out = packet_out_class()
353	1		packet_out.data = data
354	1		packet_out.actions.append(output_action)
355
356	1		return packet_out
357
358	1		def _build_lldp_flow(self, version, cookie,
359			cookie_mask=0xffffffffffffffff):
360			"""Build a Flow message to send LLDP to the controller.
361
362			Args:
363			version (int): OpenFlow version.
364
365			Returns:
366			Flow dictionary message for the specific given OpenFlow version,
367			if it is supported.
368			None if the OpenFlow version is not supported.
369
370			"""
371	1		flow = {}
372	1		match = {}
373	1		flow['priority'] = settings.FLOW_PRIORITY
374	1		flow['table_id'] = settings.TABLE_ID
375	1		flow['cookie'] = cookie
376	1		flow['cookie_mask'] = cookie_mask
377	1		match['dl_type'] = EtherType.LLDP
378	1		if self.vlan_id:
379	1		match['dl_vlan'] = self.vlan_id
380	1		flow['match'] = match
381
382	1		if version == 0x01:
383	1		flow['actions'] = [{'action_type': 'output',
384			'port': Port10.OFPP_CONTROLLER}]
385	1		elif version == 0x04:
386	1		flow['actions'] = [{'action_type': 'output',
387			'port': Port13.OFPP_CONTROLLER}]
388			else:
389			flow = None
390
391	1		return flow
392
393	1		@staticmethod
394			def _unpack_non_empty(desired_class, data):
395			"""Unpack data using an instance of desired_class.
396
397			Args:
398			desired_class (class): The class to be used to unpack data.
399			data (bytes): bytes to be unpacked.
400
401			Return:
402			An instance of desired_class class with data unpacked into it.
403
404			Raises:
405			UnpackException if the unpack could not be performed.
406
407			"""
408	1		obj = desired_class()
409
410	1		if hasattr(data, 'value'):
411	1		data = data.value
412
413	1		obj.unpack(data)
414
415	1		return obj
416
417	1		@staticmethod
418			def _get_data(req):
419			"""Get request data."""
420	1		data = req.get_json() # Valid format { "interfaces": [...] }
421	1		return data.get('interfaces', [])
422
423	1		def _get_interfaces(self):
424			"""Get all interfaces."""
425	1		interfaces = []
426	1		for switch in list(self.controller.switches.values()):
427	1		interfaces += list(switch.interfaces.values())
428	1		return interfaces
429
430	1		@staticmethod
431			def _get_interfaces_dict(interfaces):
432			"""Return a dict of interfaces."""
433	1		return {inter.id: inter for inter in interfaces}
434
435	1		def _get_lldp_interfaces(self):
436			"""Get interfaces enabled to receive LLDP packets."""
437	1		return [inter.id for inter in self._get_interfaces() if inter.lldp]
438
439	1		@rest('v1/interfaces', methods=['GET'])
440			def get_lldp_interfaces(self):
441			"""Return all the interfaces that have LLDP traffic enabled."""
442	1		return jsonify({"interfaces": self._get_lldp_interfaces()}), 200
443
444	1	View Code Duplication	@rest('v1/interfaces/disable', methods=['POST'])
			0 ignored issues – show Duplication introduced 2021-11-30 20:15 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
445			def disable_lldp(self):
446			"""Disables an interface to receive LLDP packets."""
447	1		interface_ids = self._get_data(request)
448	1		error_list = [] # List of interfaces that were not activated.
449	1		changed_interfaces = []
450	1		interface_ids = filter(None, interface_ids)
451	1		interfaces = self._get_interfaces()
452	1		if not interfaces:
453	1		return jsonify("No interfaces were found."), 404
454	1		interfaces = self._get_interfaces_dict(interfaces)
455	1		for id_ in interface_ids:
456	1		interface = interfaces.get(id_)
457	1		if interface:
458	1		interface.lldp = False
459	1		changed_interfaces.append(id_)
460			else:
461	1		error_list.append(id_)
462	1		if changed_interfaces:
463	1		self.notify_lldp_change('disabled', changed_interfaces)
464	1		if not error_list:
465	1		return jsonify(
466			"All the requested interfaces have been disabled."), 200
467
468			# Return a list of interfaces that couldn't be disabled
469	1		msg_error = "Some interfaces couldn't be found and deactivated: "
470	1		return jsonify({msg_error:
471			error_list}), 400
472
473	1	View Code Duplication	@rest('v1/interfaces/enable', methods=['POST'])
			0 ignored issues – show Duplication introduced 2021-11-30 20:15 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
474			def enable_lldp(self):
475			"""Enable an interface to receive LLDP packets."""
476	1		interface_ids = self._get_data(request)
477	1		error_list = [] # List of interfaces that were not activated.
478	1		changed_interfaces = []
479	1		interface_ids = filter(None, interface_ids)
480	1		interfaces = self._get_interfaces()
481	1		if not interfaces:
482	1		return jsonify("No interfaces were found."), 404
483	1		interfaces = self._get_interfaces_dict(interfaces)
484	1		for id_ in interface_ids:
485	1		interface = interfaces.get(id_)
486	1		if interface:
487	1		interface.lldp = True
488	1		changed_interfaces.append(id_)
489			else:
490	1		error_list.append(id_)
491	1		if changed_interfaces:
492	1		self.notify_lldp_change('enabled', changed_interfaces)
493	1		if not error_list:
494	1		return jsonify(
495			"All the requested interfaces have been enabled."), 200
496
497			# Return a list of interfaces that couldn't be enabled
498	1		msg_error = "Some interfaces couldn't be found and activated: "
499	1		return jsonify({msg_error:
500			error_list}), 400
501
502	1		@rest('v1/polling_time', methods=['GET'])
503			def get_time(self):
504			"""Get LLDP polling time in seconds."""
505	1		return jsonify({"polling_time": self.polling_time}), 200
506
507	1		@rest('v1/polling_time', methods=['POST'])
508			def set_time(self):
509			"""Set LLDP polling time."""
510			# pylint: disable=attribute-defined-outside-init
511	1		try:
512	1		payload = request.get_json()
513	1		polling_time = int(payload['polling_time'])
514	1		if polling_time <= 0:
515			raise ValueError(f"invalid polling_time {polling_time}, "
516			"must be greater than zero")
517	1		self.polling_time = polling_time
518	1		self.execute_as_loop(self.polling_time)
519	1		log.info("Polling time has been updated to %s"
520			" second(s), but this change will not be saved"
521			" permanently.", self.polling_time)
522	1		return jsonify("Polling time has been updated."), 200
523	1		except (ValueError, KeyError) as error:
524	1		msg = f"This operation is not completed: {error}"
525			return jsonify(msg), 400
526

kytos-ng / of_lldp

Pull Request — master (#36)

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