build.main.Main.on_flow_stats_check_consistency() - Code Metrics - Inspection of "Adding listening to of_core flow_stats.received to..." - kytos/flow_manager - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#125)

unknown

created 2021-05-25 18:06 UTC

build.main.Main.on_flow_stats_check_consistency() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	10
Code Lines	9

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	1
CRAP Score	14.7187

Importance

Changes

Metric	Value
cc	4
eloc	9
nop	2
dl	0
loc	10
ccs	1
cts	8
cp	0.125
crap	14.7187
rs	9.95
c	0
b	0
f	0

"""kytos/flow_manager NApp installs, lists and deletes switch flows."""
from collections import OrderedDict
from copy import deepcopy

from flask import jsonify, request
from pyof.foundation.base import UBIntBase
from pyof.v0x01.asynchronous.error_msg import BadActionCode
from pyof.v0x01.common.phy_port import PortConfig
from werkzeug.exceptions import NotFound

from kytos.core import KytosEvent, KytosNApp, log, rest
from kytos.core.helpers import listen_to
from napps.kytos.flow_manager.match import match_flow
from napps.kytos.flow_manager.storehouse import StoreHouse
from napps.kytos.of_core.flow import FlowFactory

from .exceptions import InvalidCommandError
from .settings import ENABLE_CONSISTENCY_CHECK, FLOWS_DICT_MAX_SIZE


def cast_fields(flow_dict):
    """Make casting the match fields from UBInt() to native int ."""
    match = flow_dict['match']
    for field, value in match.items():
        if isinstance(value, UBIntBase):
            match[field] = int(value)
    flow_dict['match'] = match
    return flow_dict


class Main(KytosNApp):
    """Main class to be used by Kytos controller."""

    def setup(self):
        """Replace the 'init' method for the KytosApp subclass.

        The setup method is automatically called by the run method.
        Users shouldn't call this method directly.
        """
        log.debug("flow-manager starting")
        self._flow_mods_sent = OrderedDict()
        self._flow_mods_sent_max_size = FLOWS_DICT_MAX_SIZE

        # Storehouse client to save and restore flow data:
        self.storehouse = StoreHouse(self.controller)

        # Format of stored flow data:
        # {'flow_persistence': {'dpid_str': {'flow_list': [
        #                                     {'command': '<add|delete>',
        #                                      'flow': {flow_dict}}]}}}
        self.stored_flows = {}
        self.resent_flows = set()

    def execute(self):
        """Run once on NApp 'start' or in a loop.

        The execute method is called by the run method of KytosNApp class.
        Users shouldn't call this method directly.
        """
        self._load_flows()

    def shutdown(self):
        """Shutdown routine of the NApp."""
        log.debug("flow-manager stopping")

    @listen_to('kytos/of_core.handshake.completed')
    def resend_stored_flows(self, event):
        """Resend stored Flows."""
        # if consistency check is enabled, it should take care of this
        if ENABLE_CONSISTENCY_CHECK is True:
            return
        switch = event.content['switch']
        dpid = str(switch.dpid)
        # This can be a problem because this code is running a thread
        if dpid in self.resent_flows:
            log.debug(f'Flow already resent to the switch {dpid}')
            return
        if dpid in self.stored_flows:
            flow_list = self.stored_flows[dpid]['flow_list']
            for flow in flow_list:
                command = flow['command']
                flows_dict = {"flows": [flow['flow']]}
                self._install_flows(command, flows_dict, [switch])
            self.resent_flows.add(dpid)
            log.info(f'Flows resent to Switch {dpid}')

    @listen_to('kytos/of_core.flow_stats.received')
    def on_flow_stats_check_consistency(self, event):
        """Check the consistency of a switch upon receiving flow stats."""
        if ENABLE_CONSISTENCY_CHECK is False:
            return
        switch = event.content['switch']
        if switch.is_enabled():
            self.check_storehouse_consistency(switch)
            if switch.dpid in self.stored_flows:
                self.check_switch_consistency(switch)

    def check_switch_consistency(self, switch):
        """Check consistency of installed flows for a specific switch."""
        dpid = switch.dpid

        # Flows stored in storehouse
        stored_flows = self.stored_flows[dpid]['flow_list']

        serializer = FlowFactory.get_class(switch)

        for stored_flow in stored_flows:
            command = stored_flow['command']
            stored_flow_obj = serializer.from_dict(stored_flow['flow'], switch)

            flow = {'flows': [stored_flow['flow']]}

            if stored_flow_obj not in switch.flows:
                if command == 'add':
                    log.info('A consistency problem was detected in '
                             f'switch {dpid}.')
                    self._install_flows(command, flow, [switch])
                    log.info(f'Flow forwarded to switch {dpid} to be '
                             'installed.')
            elif command == 'delete':
                log.info('A consistency problem was detected in '
                         f'switch {dpid}.')
                command = 'delete_strict'
                self._install_flows(command, flow, [switch])
                log.info(f'Flow forwarded to switch {dpid} to be deleted.')

    def check_storehouse_consistency(self, switch):
        """Check consistency of installed flows for a specific switch."""
        dpid = switch.dpid

        for installed_flow in switch.flows:
            if dpid not in self.stored_flows:
                log.info('A consistency problem was detected in '
                         f'switch {dpid}.')
                flow = {'flows': [installed_flow.as_dict()]}
                command = 'delete_strict'
                self._install_flows(command, flow, [switch])
                log.info(f'Flow forwarded to switch {dpid} to be deleted.')
            else:
                serializer = FlowFactory.get_class(switch)
                stored_flows = self.stored_flows[dpid]['flow_list']
                stored_flows_list = [serializer.from_dict(stored_flow['flow'],
                                                          switch)
                                     for stored_flow in stored_flows]

                if installed_flow not in stored_flows_list:
                    log.info('A consistency problem was detected in '
                             f'switch {dpid}.')
                    flow = {'flows': [installed_flow.as_dict()]}
                    command = 'delete_strict'
                    self._install_flows(command, flow, [switch])
                    log.info(f'Flow forwarded to switch {dpid} to be deleted.')

    # pylint: disable=attribute-defined-outside-init
    def _load_flows(self):
        """Load stored flows."""
        try:
            data = self.storehouse.get_data()['flow_persistence']
            if 'id' in data:
                del data['id']
            self.stored_flows = data
        except (KeyError, FileNotFoundError) as error:
            log.debug(f'There are no flows to load: {error}')
        else:
            log.info('Flows loaded.')

    def _store_changed_flows(self, command, flow, switch):
        """Store changed flows.

        Args:
            command: Flow command to be installed
            flow: Flows to be stored
            switch: Switch target
        """
        stored_flows_box = deepcopy(self.stored_flows)
        # if the flow has a destination dpid it can be stored.
        if not switch:
            log.info('The Flow cannot be stored, the destination switch '
                     f'have not been specified: {switch}')
            return
        installed_flow = {}
        flow_list = []
        installed_flow['command'] = command
        installed_flow['flow'] = flow
        deleted_flows = []

        serializer = FlowFactory.get_class(switch)
        installed_flow_obj = serializer.from_dict(flow, switch)

        if switch.id not in stored_flows_box:
            # Switch not stored, add to box.
            flow_list.append(installed_flow)
            stored_flows_box[switch.id] = {'flow_list': flow_list}
        else:
            stored_flows = stored_flows_box[switch.id].get('flow_list', [])
            # Check if flow already stored
            for stored_flow in stored_flows:
                stored_flow_obj = serializer.from_dict(stored_flow['flow'],
                                                       switch)

                version = switch.connection.protocol.version

                if installed_flow['command'] == 'delete':
                    # No strict match
                    if match_flow(flow, version, stored_flow['flow']):
                        deleted_flows.append(stored_flow)

                elif installed_flow_obj == stored_flow_obj:
                    if stored_flow['command'] == installed_flow['command']:
                        log.debug('Data already stored.')
                        return
                    # Flow with inconsistency in "command" fields : Remove the
                    # old instruction. This happens when there is a stored
                    # instruction to install the flow, but the new instruction
                    # is to remove it. In this case, the old instruction is
                    # removed and the new one is stored.
                    stored_flow['command'] = installed_flow.get('command')
                    deleted_flows.append(stored_flow)
                    break

            # if installed_flow['command'] != 'delete':
            stored_flows.append(installed_flow)
            for i in deleted_flows:
                stored_flows.remove(i)
            stored_flows_box[switch.id]['flow_list'] = stored_flows

        stored_flows_box['id'] = 'flow_persistence'
        self.storehouse.save_flow(stored_flows_box)
        del stored_flows_box['id']
        self.stored_flows = deepcopy(stored_flows_box)

    @rest('v2/flows')
    @rest('v2/flows/<dpid>')
    def list(self, dpid=None):
        """Retrieve all flows from a switch identified by dpid.

        If no dpid is specified, return all flows from all switches.
        """
        if dpid is None:
            switches = self.controller.switches.values()
        else:
            switches = [self.controller.get_switch_by_dpid(dpid)]

            if not any(switches):
                raise NotFound("Switch not found")

        switch_flows = {}

        for switch in switches:
            flows_dict = [cast_fields(flow.as_dict())
                          for flow in switch.flows]
            switch_flows[switch.dpid] = {'flows': flows_dict}

        return jsonify(switch_flows)

    @rest('v2/flows', methods=['POST'])
    @rest('v2/flows/<dpid>', methods=['POST'])
    def add(self, dpid=None):
        """Install new flows in the switch identified by dpid.

        If no dpid is specified, install flows in all switches.
        """
        return self._send_flow_mods_from_request(dpid, "add")

    @rest('v2/delete', methods=['POST'])
    @rest('v2/delete/<dpid>', methods=['POST'])
    @rest('v2/flows', methods=['DELETE'])
    @rest('v2/flows/<dpid>', methods=['DELETE'])
    def delete(self, dpid=None):
        """Delete existing flows in the switch identified by dpid.

        If no dpid is specified, delete flows from all switches.
        """
        return self._send_flow_mods_from_request(dpid, "delete")

    def _get_all_switches_enabled(self):
        """Get a list of all switches enabled."""
        switches = self.controller.switches.values()
        return [switch for switch in switches if switch.is_enabled()]

    def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
        """Install FlowsMods from request."""
        if flows_dict is None:
            flows_dict = request.get_json()
            if flows_dict is None:
                return jsonify({"response": 'flows dict is none.'}), 404

        if dpid:
            switch = self.controller.get_switch_by_dpid(dpid)
            if not switch:
                return jsonify({"response": 'dpid not found.'}), 404
            elif switch.is_enabled() is False:
                if command == "delete":
                    self._install_flows(command, flows_dict, [switch])
                else:
                    return jsonify({"response": 'switch is disabled.'}), 404
            else:
                self._install_flows(command, flows_dict, [switch])
        else:
            self._install_flows(command, flows_dict,
                                self._get_all_switches_enabled())

        return jsonify({"response": "FlowMod Messages Sent"})

    def _install_flows(self, command, flows_dict, switches=[]):
        """Execute all procedures to install flows in the switches.

        Args:
            command: Flow command to be installed
            flows_dict: Dictionary with flows to be installed in the switches.
            switches: A list of switches
        """
        for switch in switches:
            serializer = FlowFactory.get_class(switch)
            flows = flows_dict.get('flows', [])
            for flow_dict in flows:
                flow = serializer.from_dict(flow_dict, switch)
                if command == "delete":
                    flow_mod = flow.as_of_delete_flow_mod()
                elif command == "delete_strict":
                    flow_mod = flow.as_of_strict_delete_flow_mod()
                elif command == "add":
                    flow_mod = flow.as_of_add_flow_mod()
                else:
                    raise InvalidCommandError
                self._send_flow_mod(flow.switch, flow_mod)
                self._add_flow_mod_sent(flow_mod.header.xid, flow, command)

                self._send_napp_event(switch, flow, command)
                self._store_changed_flows(command, flow_dict, switch)

    def _add_flow_mod_sent(self, xid, flow, command):
        """Add the flow mod to the list of flow mods sent."""
        if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
            self._flow_mods_sent.popitem(last=False)
        self._flow_mods_sent[xid] = (flow, command)

    def _send_flow_mod(self, switch, flow_mod):
        event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'

        content = {'destination': switch.connection,
                   'message': flow_mod}

        event = KytosEvent(name=event_name, content=content)
        self.controller.buffers.msg_out.put(event)

    def _send_napp_event(self, switch, flow, command, **kwargs):
        """Send an Event to other apps informing about a FlowMod."""
        if command == 'add':
            name = 'kytos/flow_manager.flow.added'
        elif command in ('delete', 'delete_strict'):
            name = 'kytos/flow_manager.flow.removed'
        elif command == 'error':
            name = 'kytos/flow_manager.flow.error'
        else:
            raise InvalidCommandError
        content = {'datapath': switch,
                   'flow': flow}
        content.update(kwargs)
        event_app = KytosEvent(name, content)
        self.controller.buffers.app.put(event_app)

    @listen_to('.*.of_core.*.ofpt_error')
    def handle_errors(self, event):
        """Receive OpenFlow error and send a event.

        The event is sent only if the error is related to a request made
        by flow_manager.
        """
        message = event.content["message"]

        connection = event.source
        switch = connection.switch

        xid = message.header.xid.value
        error_type = message.error_type
        error_code = message.code
        error_data = message.data.pack()

        # Get the packet responsible for the error
        error_packet = connection.protocol.unpack(error_data)

        if message.code == BadActionCode.OFPBAC_BAD_OUT_PORT:
            actions = []
            if hasattr(error_packet, 'actions'):
                # Get actions from the flow mod (OF 1.0)
                actions = error_packet.actions
            else:
                # Get actions from the list of flow mod instructions (OF 1.3)
                for instruction in error_packet.instructions:
                    actions.extend(instruction.actions)

            for action in actions:
                iface = switch.get_interface_by_port_no(action.port)

                # Set interface to drop packets forwarded to it
                if iface:
                    iface.config = PortConfig.OFPPC_NO_FWD

        try:
            flow, error_command = self._flow_mods_sent[xid]
        except KeyError:
            pass
        else:
            self._send_napp_event(flow.switch, flow, 'error',
                                  error_command=error_command,
                                  error_type=error_type, error_code=error_code)


1		"""kytos/flow_manager NApp installs, lists and deletes switch flows."""
2	1	from collections import OrderedDict
3	1	from copy import deepcopy
4
5	1	from flask import jsonify, request
6	1	from pyof.foundation.base import UBIntBase
7	1	from pyof.v0x01.asynchronous.error_msg import BadActionCode
8	1	from pyof.v0x01.common.phy_port import PortConfig
9	1	from werkzeug.exceptions import NotFound
10
11	1	from kytos.core import KytosEvent, KytosNApp, log, rest
12	1	from kytos.core.helpers import listen_to
13	1	from napps.kytos.flow_manager.match import match_flow
14	1	from napps.kytos.flow_manager.storehouse import StoreHouse
15	1	from napps.kytos.of_core.flow import FlowFactory
16
17	1	from .exceptions import InvalidCommandError
18	1	from .settings import ENABLE_CONSISTENCY_CHECK, FLOWS_DICT_MAX_SIZE
19
20
21	1	def cast_fields(flow_dict):
22		"""Make casting the match fields from UBInt() to native int ."""
23	1	match = flow_dict['match']
24	1	for field, value in match.items():
25	1	if isinstance(value, UBIntBase):
26		match[field] = int(value)
27	1	flow_dict['match'] = match
28	1	return flow_dict
29
30
31	1	class Main(KytosNApp):
32		"""Main class to be used by Kytos controller."""
33
34	1	def setup(self):
35		"""Replace the 'init' method for the KytosApp subclass.
36
37		The setup method is automatically called by the run method.
38		Users shouldn't call this method directly.
39		"""
40	1	log.debug("flow-manager starting")
41	1	self._flow_mods_sent = OrderedDict()
42	1	self._flow_mods_sent_max_size = FLOWS_DICT_MAX_SIZE
43
44		# Storehouse client to save and restore flow data:
45	1	self.storehouse = StoreHouse(self.controller)
46
47		# Format of stored flow data:
48		# {'flow_persistence': {'dpid_str': {'flow_list': [
49		# {'command': '<add\|delete>',
50		# 'flow': {flow_dict}}]}}}
51	1	self.stored_flows = {}
52	1	self.resent_flows = set()
53
54	1	def execute(self):
55		"""Run once on NApp 'start' or in a loop.
56
57		The execute method is called by the run method of KytosNApp class.
58		Users shouldn't call this method directly.
59		"""
60		self._load_flows()
61
62	1	def shutdown(self):
63		"""Shutdown routine of the NApp."""
64		log.debug("flow-manager stopping")
65
66	1	@listen_to('kytos/of_core.handshake.completed')
67		def resend_stored_flows(self, event):
68		"""Resend stored Flows."""
69		# if consistency check is enabled, it should take care of this
70	1	if ENABLE_CONSISTENCY_CHECK is True:
71		return
72	1	switch = event.content['switch']
73	1	dpid = str(switch.dpid)
74		# This can be a problem because this code is running a thread
75	1	if dpid in self.resent_flows:
76		log.debug(f'Flow already resent to the switch {dpid}')
77		return
78	1	if dpid in self.stored_flows:
79	1	flow_list = self.stored_flows[dpid]['flow_list']
80	1	for flow in flow_list:
81	1	command = flow['command']
82	1	flows_dict = {"flows": [flow['flow']]}
83	1	self._install_flows(command, flows_dict, [switch])
84	1	self.resent_flows.add(dpid)
85	1	log.info(f'Flows resent to Switch {dpid}')
86
87	1	@listen_to('kytos/of_core.flow_stats.received')
88		def on_flow_stats_check_consistency(self, event):
89		"""Check the consistency of a switch upon receiving flow stats."""
90		if ENABLE_CONSISTENCY_CHECK is False:
91		return
92		switch = event.content['switch']
93		if switch.is_enabled():
94		self.check_storehouse_consistency(switch)
95		if switch.dpid in self.stored_flows:
96		self.check_switch_consistency(switch)
97
98	1	def check_switch_consistency(self, switch):
99		"""Check consistency of installed flows for a specific switch."""
100	1	dpid = switch.dpid
101
102		# Flows stored in storehouse
103	1	stored_flows = self.stored_flows[dpid]['flow_list']
104
105	1	serializer = FlowFactory.get_class(switch)
106
107	1	for stored_flow in stored_flows:
108	1	command = stored_flow['command']
109	1	stored_flow_obj = serializer.from_dict(stored_flow['flow'], switch)
110
111	1	flow = {'flows': [stored_flow['flow']]}
112
113	1	if stored_flow_obj not in switch.flows:
114	1	if command == 'add':
115	1	log.info('A consistency problem was detected in '
116		f'switch {dpid}.')
117	1	self._install_flows(command, flow, [switch])
118	1	log.info(f'Flow forwarded to switch {dpid} to be '
119		'installed.')
120	1	elif command == 'delete':
121	1	log.info('A consistency problem was detected in '
122		f'switch {dpid}.')
123	1	command = 'delete_strict'
124	1	self._install_flows(command, flow, [switch])
125	1	log.info(f'Flow forwarded to switch {dpid} to be deleted.')
126
127	1	def check_storehouse_consistency(self, switch):
128		"""Check consistency of installed flows for a specific switch."""
129	1	dpid = switch.dpid
130
131	1	for installed_flow in switch.flows:
132	1	if dpid not in self.stored_flows:
133		log.info('A consistency problem was detected in '
134		f'switch {dpid}.')
135		flow = {'flows': [installed_flow.as_dict()]}
136		command = 'delete_strict'
137		self._install_flows(command, flow, [switch])
138		log.info(f'Flow forwarded to switch {dpid} to be deleted.')
139		else:
140	1	serializer = FlowFactory.get_class(switch)
141	1	stored_flows = self.stored_flows[dpid]['flow_list']
142	1	stored_flows_list = [serializer.from_dict(stored_flow['flow'],
143		switch)
144		for stored_flow in stored_flows]
145
146	1	if installed_flow not in stored_flows_list:
147	1	log.info('A consistency problem was detected in '
148		f'switch {dpid}.')
149	1	flow = {'flows': [installed_flow.as_dict()]}
150	1	command = 'delete_strict'
151	1	self._install_flows(command, flow, [switch])
152	1	log.info(f'Flow forwarded to switch {dpid} to be deleted.')
153
154		# pylint: disable=attribute-defined-outside-init
155	1	def _load_flows(self):
156		"""Load stored flows."""
157	1	try:
158	1	data = self.storehouse.get_data()['flow_persistence']
159	1	if 'id' in data:
160		del data['id']
161	1	self.stored_flows = data
162		except (KeyError, FileNotFoundError) as error:
163		log.debug(f'There are no flows to load: {error}')
164		else:
165	1	log.info('Flows loaded.')
166
167	1	def _store_changed_flows(self, command, flow, switch):
168		"""Store changed flows.
169
170		Args:
171		command: Flow command to be installed
172		flow: Flows to be stored
173		switch: Switch target
174		"""
175	1	stored_flows_box = deepcopy(self.stored_flows)
176		# if the flow has a destination dpid it can be stored.
177	1	if not switch:
178		log.info('The Flow cannot be stored, the destination switch '
179		f'have not been specified: {switch}')
180		return
181	1	installed_flow = {}
182	1	flow_list = []
183	1	installed_flow['command'] = command
184	1	installed_flow['flow'] = flow
185	1	deleted_flows = []
186
187	1	serializer = FlowFactory.get_class(switch)
188	1	installed_flow_obj = serializer.from_dict(flow, switch)
189
190	1	if switch.id not in stored_flows_box:
191		# Switch not stored, add to box.
192	1	flow_list.append(installed_flow)
193	1	stored_flows_box[switch.id] = {'flow_list': flow_list}
194		else:
195	1	stored_flows = stored_flows_box[switch.id].get('flow_list', [])
196		# Check if flow already stored
197	1	for stored_flow in stored_flows:
198	1	stored_flow_obj = serializer.from_dict(stored_flow['flow'],
199		switch)
200
201	1	version = switch.connection.protocol.version
202
203	1	if installed_flow['command'] == 'delete':
204		# No strict match
205	1	if match_flow(flow, version, stored_flow['flow']):
206	1	deleted_flows.append(stored_flow)
207
208	1	elif installed_flow_obj == stored_flow_obj:
209	1	if stored_flow['command'] == installed_flow['command']:
210		log.debug('Data already stored.')
211		return
212		# Flow with inconsistency in "command" fields : Remove the
213		# old instruction. This happens when there is a stored
214		# instruction to install the flow, but the new instruction
215		# is to remove it. In this case, the old instruction is
216		# removed and the new one is stored.
217	1	stored_flow['command'] = installed_flow.get('command')
218	1	deleted_flows.append(stored_flow)
219	1	break
220
221		# if installed_flow['command'] != 'delete':
222	1	stored_flows.append(installed_flow)
223	1	for i in deleted_flows:
224	1	stored_flows.remove(i)
225	1	stored_flows_box[switch.id]['flow_list'] = stored_flows
226
227	1	stored_flows_box['id'] = 'flow_persistence'
228	1	self.storehouse.save_flow(stored_flows_box)
229	1	del stored_flows_box['id']
230	1	self.stored_flows = deepcopy(stored_flows_box)
231
232	1	@rest('v2/flows')
233	1	@rest('v2/flows/<dpid>')
234	1	def list(self, dpid=None):
235		"""Retrieve all flows from a switch identified by dpid.
236
237		If no dpid is specified, return all flows from all switches.
238		"""
239	1	if dpid is None:
240	1	switches = self.controller.switches.values()
241		else:
242	1	switches = [self.controller.get_switch_by_dpid(dpid)]
243
244	1	if not any(switches):
245	1	raise NotFound("Switch not found")
246
247	1	switch_flows = {}
248
249	1	for switch in switches:
250	1	flows_dict = [cast_fields(flow.as_dict())
251		for flow in switch.flows]
252	1	switch_flows[switch.dpid] = {'flows': flows_dict}
253
254	1	return jsonify(switch_flows)
255
256	1	@rest('v2/flows', methods=['POST'])
257	1	@rest('v2/flows/<dpid>', methods=['POST'])
258	1	def add(self, dpid=None):
259		"""Install new flows in the switch identified by dpid.
260
261		If no dpid is specified, install flows in all switches.
262		"""
263	1	return self._send_flow_mods_from_request(dpid, "add")
264
265	1	@rest('v2/delete', methods=['POST'])
266	1	@rest('v2/delete/<dpid>', methods=['POST'])
267	1	@rest('v2/flows', methods=['DELETE'])
268	1	@rest('v2/flows/<dpid>', methods=['DELETE'])
269	1	def delete(self, dpid=None):
270		"""Delete existing flows in the switch identified by dpid.
271
272		If no dpid is specified, delete flows from all switches.
273		"""
274	1	return self._send_flow_mods_from_request(dpid, "delete")
275
276	1	def _get_all_switches_enabled(self):
277		"""Get a list of all switches enabled."""
278	1	switches = self.controller.switches.values()
279	1	return [switch for switch in switches if switch.is_enabled()]
280
281	1	def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
282		"""Install FlowsMods from request."""
283	1	if flows_dict is None:
284	1	flows_dict = request.get_json()
285	1	if flows_dict is None:
286	1	return jsonify({"response": 'flows dict is none.'}), 404
287
288	1	if dpid:
289	1	switch = self.controller.get_switch_by_dpid(dpid)
290	1	if not switch:
291	1	return jsonify({"response": 'dpid not found.'}), 404
292	1	elif switch.is_enabled() is False:
293	1	if command == "delete":
294	1	self._install_flows(command, flows_dict, [switch])
295		else:
296	1	return jsonify({"response": 'switch is disabled.'}), 404
297		else:
298	1	self._install_flows(command, flows_dict, [switch])
299		else:
300	1	self._install_flows(command, flows_dict,
301		self._get_all_switches_enabled())
302
303	1	return jsonify({"response": "FlowMod Messages Sent"})
304
305	1	def _install_flows(self, command, flows_dict, switches=[]):
306		"""Execute all procedures to install flows in the switches.
307
308		Args:
309		command: Flow command to be installed
310		flows_dict: Dictionary with flows to be installed in the switches.
311		switches: A list of switches
312		"""
313	1	for switch in switches:
314	1	serializer = FlowFactory.get_class(switch)
315	1	flows = flows_dict.get('flows', [])
316	1	for flow_dict in flows:
317	1	flow = serializer.from_dict(flow_dict, switch)
318	1	if command == "delete":
319		flow_mod = flow.as_of_delete_flow_mod()
320	1	elif command == "delete_strict":
321	1	flow_mod = flow.as_of_strict_delete_flow_mod()
322	1	elif command == "add":
323	1	flow_mod = flow.as_of_add_flow_mod()
324		else:
325		raise InvalidCommandError
326	1	self._send_flow_mod(flow.switch, flow_mod)
327	1	self._add_flow_mod_sent(flow_mod.header.xid, flow, command)
328
329	1	self._send_napp_event(switch, flow, command)
330	1	self._store_changed_flows(command, flow_dict, switch)
331
332	1	def _add_flow_mod_sent(self, xid, flow, command):
333		"""Add the flow mod to the list of flow mods sent."""
334	1	if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
335		self._flow_mods_sent.popitem(last=False)
336	1	self._flow_mods_sent[xid] = (flow, command)
337
338	1	def _send_flow_mod(self, switch, flow_mod):
339	1	event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'
340
341	1	content = {'destination': switch.connection,
342		'message': flow_mod}
343
344	1	event = KytosEvent(name=event_name, content=content)
345	1	self.controller.buffers.msg_out.put(event)
346
347	1	def _send_napp_event(self, switch, flow, command, **kwargs):
348		"""Send an Event to other apps informing about a FlowMod."""
349	1	if command == 'add':
350	1	name = 'kytos/flow_manager.flow.added'
351	1	elif command in ('delete', 'delete_strict'):
352	1	name = 'kytos/flow_manager.flow.removed'
353	1	elif command == 'error':
354	1	name = 'kytos/flow_manager.flow.error'
355		else:
356		raise InvalidCommandError
357	1	content = {'datapath': switch,
358		'flow': flow}
359	1	content.update(kwargs)
360	1	event_app = KytosEvent(name, content)
361	1	self.controller.buffers.app.put(event_app)
362
363	1	@listen_to('..of_core..ofpt_error')
364		def handle_errors(self, event):
365		"""Receive OpenFlow error and send a event.
366
367		The event is sent only if the error is related to a request made
368		by flow_manager.
369		"""
370	1	message = event.content["message"]
371
372	1	connection = event.source
373	1	switch = connection.switch
374
375	1	xid = message.header.xid.value
376	1	error_type = message.error_type
377	1	error_code = message.code
378	1	error_data = message.data.pack()
379
380		# Get the packet responsible for the error
381	1	error_packet = connection.protocol.unpack(error_data)
382
383	1	if message.code == BadActionCode.OFPBAC_BAD_OUT_PORT:
384		actions = []
385		if hasattr(error_packet, 'actions'):
386		# Get actions from the flow mod (OF 1.0)
387		actions = error_packet.actions
388		else:
389		# Get actions from the list of flow mod instructions (OF 1.3)
390		for instruction in error_packet.instructions:
391		actions.extend(instruction.actions)
392
393		for action in actions:
394		iface = switch.get_interface_by_port_no(action.port)
395
396		# Set interface to drop packets forwarded to it
397		if iface:
398		iface.config = PortConfig.OFPPC_NO_FWD
399
400	1	try:
401	1	flow, error_command = self._flow_mods_sent[xid]
402		except KeyError:
403		pass
404		else:
405	1	self._send_napp_event(flow.switch, flow, 'error',
406		error_command=error_command,
407		error_type=error_type, error_code=error_code)
408

kytos / flow_manager

Pull Request — master (#125)

build.main.Main.on_flow_stats_check_consistency() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like