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Pull Request — master (#56)
by Carlos
02:10
created

build.main.Main.install_lldp_flow()   A

Complexity

Conditions 3

Size

Total Lines 25
Code Lines 14

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 11
CRAP Score 3.0327

Importance

Changes 0
Metric Value
cc 3
eloc 14
nop 2
dl 0
loc 25
ccs 11
cts 13
cp 0.8462
crap 3.0327
rs 9.7
c 0
b 0
f 0
1
"""NApp responsible to discover new switches and hosts."""
2 1
import struct
3
4 1
import requests
5 1
from flask import jsonify, request
6 1
from pyof.foundation.basic_types import DPID, UBInt16, UBInt32
7 1
from pyof.foundation.network_types import LLDP, VLAN, Ethernet, EtherType
8 1
from pyof.v0x01.common.action import ActionOutput as AO10
9 1
from pyof.v0x01.common.phy_port import Port as Port10
10 1
from pyof.v0x01.controller2switch.packet_out import PacketOut as PO10
11 1
from pyof.v0x04.common.action import ActionOutput as AO13
12 1
from pyof.v0x04.common.port import PortNo as Port13
13 1
from pyof.v0x04.controller2switch.packet_out import PacketOut as PO13
14
15 1
from kytos.core import KytosEvent, KytosNApp, log, rest
16 1
from kytos.core.helpers import listen_to
17 1
from napps.kytos.of_lldp import constants, settings
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19
20 1
class Main(KytosNApp):
21
    """Main OF_LLDP NApp Class."""
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23 1
    def setup(self):
24
        """Make this NApp run in a loop."""
25 1
        self.vlan_id = None
26 1
        self.polling_time = settings.POLLING_TIME
27 1
        if hasattr(settings, "FLOW_VLAN_VID"):
28 1
            self.vlan_id = settings.FLOW_VLAN_VID
29 1
        self.execute_as_loop(self.polling_time)
30
31 1
    def execute(self):
32
        """Send LLDP Packets every 'POLLING_TIME' seconds to all switches."""
33 1
        switches = list(self.controller.switches.values())
34 1
        for switch in switches:
35 1
            try:
36 1
                of_version = switch.connection.protocol.version
37
            except AttributeError:
38
                of_version = None
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40 1
            if not switch.is_connected():
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                continue
42
43 1
            if of_version == 0x01:
44 1
                port_type = UBInt16
45 1
                local_port = Port10.OFPP_LOCAL
46 1
            elif of_version == 0x04:
47 1
                port_type = UBInt32
48 1
                local_port = Port13.OFPP_LOCAL
49
            else:
50
                # skip the current switch with unsupported OF version
51
                continue
52
53 1
            interfaces = list(switch.interfaces.values())
54 1
            for interface in interfaces:
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                # Interface marked to receive lldp packet
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                # Only send LLDP packet to active interface
57 1
                if(not interface.lldp or not interface.is_active()
58
                   or not interface.is_enabled()):
59
                    continue
60
                # Avoid the interface that connects to the controller.
61 1
                if interface.port_number == local_port:
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                    continue
63
64 1
                lldp = LLDP()
65 1
                lldp.chassis_id.sub_value = DPID(switch.dpid)
66 1
                lldp.port_id.sub_value = port_type(interface.port_number)
67
68 1
                ethernet = Ethernet()
69 1
                ethernet.ether_type = EtherType.LLDP
70 1
                ethernet.source = interface.address
71 1
                ethernet.destination = constants.LLDP_MULTICAST_MAC
72 1
                ethernet.data = lldp.pack()
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                # self.vlan_id == None will result in a packet with no VLAN.
74 1
                ethernet.vlans.append(VLAN(vid=self.vlan_id))
75
76 1
                packet_out = self._build_lldp_packet_out(
77
                                    of_version,
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                                    interface.port_number, ethernet.pack())
79
80 1
                if packet_out is None:
81
                    continue
82
83 1
                event_out = KytosEvent(
84
                    name='kytos/of_lldp.messages.out.ofpt_packet_out',
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                    content={
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                            'destination': switch.connection,
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                            'message': packet_out})
88 1
                self.controller.buffers.msg_out.put(event_out)
89 1
                log.debug(
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                    "Sending a LLDP PacketOut to the switch %s",
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                    switch.dpid)
92
93 1
                msg = '\n'
94 1
                msg += 'Switch: %s (%s)\n'
95 1
                msg += ' Interfaces: %s\n'
96 1
                msg += ' -- LLDP PacketOut --\n'
97 1
                msg += ' Ethernet: eth_type (%s) | src (%s) | dst (%s)'
98 1
                msg += '\n'
99 1
                msg += ' LLDP: Switch (%s) | port (%s)'
100
101 1
                log.debug(
102
                    msg,
103
                    switch.connection.address, switch.dpid,
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                    switch.interfaces, ethernet.ether_type,
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                    ethernet.source, ethernet.destination,
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                    switch.dpid, interface.port_number)
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108 1
    @listen_to('kytos/topology.switch.(enabled|disabled)')
109
    def install_lldp_flow(self, event):
110
        """Install a flow to send LLDP packets to the controller.
111
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        The proactive flow is installed whenever a switch connects.
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        Args:
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            event (:class:`~kytos.core.events.KytosEvent`):
116
                Event with new switch information.
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118
        """
119 1
        try:
120 1
            dpid = event.content['dpid']
121 1
            switch = self.controller.get_switch_by_dpid(dpid)
122 1
            of_version = switch.connection.protocol.version
123
124
        except AttributeError:
125
            of_version = None
126
127 1
        flow = self._build_lldp_flow(of_version)
128 1
        if flow:
129 1
            destination = switch.id
130 1
            endpoint = f'{settings.FLOW_MANAGER_URL}/flows/{destination}'
131 1
            data = {'flows': [flow]}
132 1
            requests.post(endpoint, json=data)
133
134 1
    @listen_to('kytos/of_core.v0x0[14].messages.in.ofpt_packet_in')
135
    def notify_uplink_detected(self, event):
136
        """Dispatch two KytosEvents to notify identified NNI interfaces.
137
138
        Args:
139
            event (:class:`~kytos.core.events.KytosEvent`):
140
                Event with an LLDP packet as data.
141
142
        """
143 1
        ethernet = self._unpack_non_empty(Ethernet, event.message.data)
144 1
        if ethernet.ether_type == EtherType.LLDP:
145 1
            try:
146 1
                lldp = self._unpack_non_empty(LLDP, ethernet.data)
147 1
                dpid = self._unpack_non_empty(DPID, lldp.chassis_id.sub_value)
148
            except struct.error:
149
                #: If we have a LLDP packet but we cannot unpack it, or the
150
                #: unpacked packet does not contain the dpid attribute, then
151
                #: we are dealing with a LLDP generated by someone else. Thus
152
                #: this packet is not useful for us and we may just ignore it.
153
                return
154
155 1
            switch_a = event.source.switch
156 1
            port_a = event.message.in_port
157 1
            switch_b = None
158 1
            port_b = None
159
160
            # in_port is currently a UBInt16 in v0x01 and an Int in v0x04.
161 1
            if isinstance(port_a, int):
162 1
                port_a = UBInt32(port_a)
163
164 1
            try:
165 1
                switch_b = self.controller.get_switch_by_dpid(dpid.value)
166 1
                of_version = switch_b.connection.protocol.version
167 1
                port_type = UBInt16 if of_version == 0x01 else UBInt32
168 1
                port_b = self._unpack_non_empty(port_type,
169
                                                lldp.port_id.sub_value)
170
            except AttributeError:
171
                log.debug("Couldn't find datapath %s.", dpid.value)
172
173
            # Return if any of the needed information are not available
174 1
            if not (switch_a and port_a and switch_b and port_b):
175
                return
176
177 1
            interface_a = switch_a.get_interface_by_port_no(port_a.value)
178 1
            interface_b = switch_b.get_interface_by_port_no(port_b.value)
179
180 1
            event_out = KytosEvent(name='kytos/of_lldp.interface.is.nni',
181
                                   content={'interface_a': interface_a,
182
                                            'interface_b': interface_b})
183 1
            self.controller.buffers.app.put(event_out)
184
185 1
    def notify_lldp_change(self, state, interface_ids):
186
        """Dispatch a KytosEvent to notify changes to the LLDP status."""
187 1
        content = {'attribute': 'LLDP',
188
                   'state': state,
189
                   'interface_ids': interface_ids}
190 1
        event_out = KytosEvent(name='kytos/of_lldp.network_status.updated',
191
                               content=content)
192 1
        self.controller.buffers.app.put(event_out)
193
194 1
    def shutdown(self):
195
        """End of the application."""
196
        log.debug('Shutting down...')
197
198 1
    @staticmethod
199
    def _build_lldp_packet_out(version, port_number, data):
200
        """Build a LLDP PacketOut message.
201
202
        Args:
203
            version (int): OpenFlow version
204
            port_number (int): Switch port number where the packet must be
205
                forwarded to.
206
            data (bytes): Binary data to be sent through the port.
207
208
        Returns:
209
            PacketOut message for the specific given OpenFlow version, if it
210
                is supported.
211
            None if the OpenFlow version is not supported.
212
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        """
214 1
        if version == 0x01:
215 1
            action_output_class = AO10
216 1
            packet_out_class = PO10
217 1
        elif version == 0x04:
218 1
            action_output_class = AO13
219 1
            packet_out_class = PO13
220
        else:
221 1
            log.info('Openflow version %s is not yet supported.', version)
222 1
            return None
223
224 1
        output_action = action_output_class()
225 1
        output_action.port = port_number
226
227 1
        packet_out = packet_out_class()
228 1
        packet_out.data = data
229 1
        packet_out.actions.append(output_action)
230
231 1
        return packet_out
232
233 1
    def _build_lldp_flow(self, version):
234
        """Build a Flow message to send LLDP to the controller.
235
236
        Args:
237
            version (int): OpenFlow version.
238
239
        Returns:
240
            Flow dictionary message for the specific given OpenFlow version,
241
            if it is supported.
242
            None if the OpenFlow version is not supported.
243
244
        """
245 1
        flow = {}
246 1
        match = {}
247 1
        flow['priority'] = settings.FLOW_PRIORITY
248 1
        match['dl_type'] = EtherType.LLDP
249 1
        if self.vlan_id:
250 1
            match['dl_vlan'] = self.vlan_id
251 1
        flow['match'] = match
252
253 1
        if version == 0x01:
254 1
            flow['actions'] = [{'action_type': 'output',
255
                                'port': Port10.OFPP_CONTROLLER}]
256 1
        elif version == 0x04:
257 1
            flow['actions'] = [{'action_type': 'output',
258
                                'port': Port13.OFPP_CONTROLLER}]
259
        else:
260
            flow = None
261
262 1
        return flow
263
264 1
    @staticmethod
265
    def _unpack_non_empty(desired_class, data):
266
        """Unpack data using an instance of desired_class.
267
268
        Args:
269
            desired_class (class): The class to be used to unpack data.
270
            data (bytes): bytes to be unpacked.
271
272
        Return:
273
            An instance of desired_class class with data unpacked into it.
274
275
        Raises:
276
            UnpackException if the unpack could not be performed.
277
278
        """
279 1
        obj = desired_class()
280
281 1
        if hasattr(data, 'value'):
282 1
            data = data.value
283
284 1
        obj.unpack(data)
285
286 1
        return obj
287
288 1
    @staticmethod
289
    def _get_data(req):
290
        """Get request data."""
291 1
        data = req.get_json()  # Valid format { "interfaces": [...] }
292 1
        return data.get('interfaces', [])
293
294 1
    def _get_interfaces(self):
295
        """Get all interfaces."""
296 1
        interfaces = []
297 1
        for switch in list(self.controller.switches.values()):
298 1
            interfaces += list(switch.interfaces.values())
299 1
        return interfaces
300
301 1
    @staticmethod
302
    def _get_interfaces_dict(interfaces):
303
        """Return a dict of interfaces."""
304 1
        return {inter.id: inter for inter in interfaces}
305
306 1
    def _get_lldp_interfaces(self):
307
        """Get interfaces enabled to receive LLDP packets."""
308 1
        return [inter.id for inter in self._get_interfaces() if inter.lldp]
309
310 1
    @rest('v1/interfaces', methods=['GET'])
311
    def get_lldp_interfaces(self):
312
        """Return all the interfaces that have LLDP traffic enabled."""
313 1
        return jsonify({"interfaces": self._get_lldp_interfaces()}), 200
314
315 1 View Code Duplication
    @rest('v1/interfaces/disable', methods=['POST'])
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316
    def disable_lldp(self):
317
        """Disables an interface to receive LLDP packets."""
318 1
        interface_ids = self._get_data(request)
319 1
        error_list = []  # List of interfaces that were not activated.
320 1
        changed_interfaces = []
321 1
        interface_ids = filter(None, interface_ids)
322 1
        interfaces = self._get_interfaces()
323 1
        if not interfaces:
324 1
            return jsonify("No interfaces were found."), 404
325 1
        interfaces = self._get_interfaces_dict(interfaces)
326 1
        for id_ in interface_ids:
327 1
            interface = interfaces.get(id_)
328 1
            if interface:
329 1
                interface.lldp = False
330 1
                changed_interfaces.append(id_)
331
            else:
332 1
                error_list.append(id_)
333 1
        if changed_interfaces:
334 1
            self.notify_lldp_change('disabled', changed_interfaces)
335 1
        if not error_list:
336 1
            return jsonify(
337
                "All the requested interfaces have been disabled."), 200
338
339
        # Return a list of interfaces that couldn't be disabled
340 1
        msg_error = "Some interfaces couldn't be found and deactivated: "
341 1
        return jsonify({msg_error:
342
                        error_list}), 400
343
344 1 View Code Duplication
    @rest('v1/interfaces/enable', methods=['POST'])
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345
    def enable_lldp(self):
346
        """Enable an interface to receive LLDP packets."""
347 1
        interface_ids = self._get_data(request)
348 1
        error_list = []  # List of interfaces that were not activated.
349 1
        changed_interfaces = []
350 1
        interface_ids = filter(None, interface_ids)
351 1
        interfaces = self._get_interfaces()
352 1
        if not interfaces:
353 1
            return jsonify("No interfaces were found."), 404
354 1
        interfaces = self._get_interfaces_dict(interfaces)
355 1
        for id_ in interface_ids:
356 1
            interface = interfaces.get(id_)
357 1
            if interface:
358 1
                interface.lldp = True
359 1
                changed_interfaces.append(id_)
360
            else:
361 1
                error_list.append(id_)
362 1
        if changed_interfaces:
363 1
            self.notify_lldp_change('enabled', changed_interfaces)
364 1
        if not error_list:
365 1
            return jsonify(
366
                "All the requested interfaces have been enabled."), 200
367
368
        # Return a list of interfaces that couldn't be enabled
369 1
        msg_error = "Some interfaces couldn't be found and activated: "
370 1
        return jsonify({msg_error:
371
                        error_list}), 400
372
373 1
    @rest('v1/polling_time', methods=['GET'])
374
    def get_time(self):
375
        """Get LLDP polling time in seconds."""
376 1
        return jsonify({"polling_time": self.polling_time}), 200
377
378 1
    @rest('v1/polling_time', methods=['POST'])
379
    def set_time(self):
380
        """Set LLDP polling time."""
381
        # pylint: disable=attribute-defined-outside-init
382 1
        try:
383 1
            payload = request.get_json()
384 1
            polling_time = int(payload['polling_time'])
385 1
            if polling_time <= 0:
386
                raise ValueError(f"invalid polling_time {polling_time}, "
387
                                 "must be greater than zero")
388 1
            self.polling_time = polling_time
389 1
            self.execute_as_loop(self.polling_time)
390 1
            log.info("Polling time has been updated to %s"
391
                     " second(s), but this change will not be saved"
392
                     " permanently.", self.polling_time)
393 1
            return jsonify("Polling time has been updated."), 200
394 1
        except (ValueError, KeyError) as error:
395 1
            msg = f"This operation is not completed: {error}"
396
            return jsonify(msg), 400
397