build.main.Main.check_switch_consistency() - Code Metrics - Inspection of "Add support to list of exceptions in consistency m..." - kytos/flow_manager - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#112)

by Carlos

created 2021-02-26 13:11 UTC

build.main.Main.check_switch_consistency() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	27
Code Lines	17

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	17
CRAP Score	5

Importance

Changes

Metric	Value
cc	5
eloc	17
nop	2
dl	0
loc	27
ccs	17
cts	17
cp	1
crap	5
rs	9.0833
c	0
b	0
f	0

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

from flask import jsonify, request
from pyof.v0x01.asynchronous.error_msg import BadActionCode
from pyof.v0x01.common.phy_port import PortConfig

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

from .exceptions import InvalidCommandError
from .settings import (CONSISTENCY_COOKIE_EXCEPTION_RANGE,
                       CONSISTENCY_INTERVAL,
                       CONSISTENCY_TABLE_ID_EXCEPTION_RANGE,
                       FLOWS_DICT_MAX_SIZE)


def _is_valid_range(values, instance):
    """Check if the exception range is valid."""
    if len(values) != 2:
        msg = f'The Tuple must have size of 2, Size: {len(values)}'
        raise ValueError(msg)
    first, second = values
    if second < first:
        msg = (f'The first value is bigger than the second: {values}')
        raise ValueError(msg)
    if not isinstance(first, instance) or not isinstance(second, instance):
        msg = 'The elements of the range must be of the class {instance}'
        raise TypeError(msg)


def validate_input(exceptions):
    """Check that the list of exceptions is well formatted.

    Returns True if the consistency exception input are well formatted.
    """
    msg = ('The list of consistency exception is not well formatted'
           ', it will be ignored: %s')
    for exception in exceptions:
        if isinstance(exception, tuple):
            try:
                _is_valid_range(exception, int)
            except (TypeError, ValueError) as error:
                log.warn(msg, error)
                return False
        elif not isinstance(exception, int):
            error_msg = ('The elements must be of class int or tuple'
                         f' but they are: {type(exception)}')
            log.warn(msg, error_msg)
            return False
    return True


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
        self.cookie_exception_range = []
        self.tab_id_exception_range = []
        if validate_input(CONSISTENCY_COOKIE_EXCEPTION_RANGE):
            self.cookie_exception_range = CONSISTENCY_COOKIE_EXCEPTION_RANGE
        if validate_input(CONSISTENCY_TABLE_ID_EXCEPTION_RANGE):
            self.tab_id_exception_range = CONSISTENCY_TABLE_ID_EXCEPTION_RANGE

        # 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()
        if CONSISTENCY_INTERVAL > 0:
            self.execute_as_loop(CONSISTENCY_INTERVAL)

    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()

        if CONSISTENCY_INTERVAL > 0:
            self.consistency_check()

    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."""
        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}')

    @staticmethod
    def is_exception(field, exceptions):
        """Check if the field are in the list of exceptions.

        Returns True if the field is in the list of exceptions.
        """
        for i in exceptions:
            if isinstance(i, tuple):
                begin_interval, end_interval = i
                if begin_interval <= field <= end_interval:
                    return True
            if isinstance(i, int):
                if field == i:
                    return True
        return False

    def consistency_exception_check(self, flow):
        """Verify if the flow is in the exception range.

        Check by `cookie` range and `table_id` range.
        Returns True if the flow is in the exception list.
        """
        # Check by cookie
        if self.is_exception(flow.cookie, self.cookie_exception_range):
            return True

        # Check by `table_id`
        if self.is_exception(flow.table_id, self.tab_id_exception_range):
            return True
        return False

    def consistency_check(self):
        """Check the consistency of flows in each switch."""
        switches = self.controller.switches.values()

        for switch in switches:
            # Check if a dpid is a key in 'stored_flows' dictionary
            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}.')
                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:

            # Check if the flow are in the excluded flow list
            if self.consistency_exception_check(installed_flow):
                continue

            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'
                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'
                    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 = self.stored_flows.copy()
        # 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

        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)
                if 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')
                    stored_flows.remove(stored_flow)
                    break

            stored_flows.append(installed_flow)
            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 = stored_flows_box.copy()

    @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)]

        switch_flows = {}

        for switch in switches:
            flows_dict = [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 == "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 == 'delete':
            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
4	1	from flask import jsonify, request
5	1	from pyof.v0x01.asynchronous.error_msg import BadActionCode
6	1	from pyof.v0x01.common.phy_port import PortConfig
7
8	1	from kytos.core import KytosEvent, KytosNApp, log, rest
9	1	from kytos.core.helpers import listen_to
10	1	from napps.kytos.flow_manager.storehouse import StoreHouse
11	1	from napps.kytos.of_core.flow import FlowFactory
12
13	1	from .exceptions import InvalidCommandError
14	1	from .settings import (CONSISTENCY_COOKIE_EXCEPTION_RANGE,
15		CONSISTENCY_INTERVAL,
16		CONSISTENCY_TABLE_ID_EXCEPTION_RANGE,
17		FLOWS_DICT_MAX_SIZE)
18
19
20	1	def _is_valid_range(values, instance):
21		"""Check if the exception range is valid."""
22		if len(values) != 2:
23		msg = f'The Tuple must have size of 2, Size: {len(values)}'
24		raise ValueError(msg)
25		first, second = values
26		if second < first:
27		msg = (f'The first value is bigger than the second: {values}')
28		raise ValueError(msg)
29		if not isinstance(first, instance) or not isinstance(second, instance):
30		msg = 'The elements of the range must be of the class {instance}'
31		raise TypeError(msg)
32
33
34	1	def validate_input(exceptions):
35		"""Check that the list of exceptions is well formatted.
36
37		Returns True if the consistency exception input are well formatted.
38		"""
39	1	msg = ('The list of consistency exception is not well formatted'
40		', it will be ignored: %s')
41	1	for exception in exceptions:
42		if isinstance(exception, tuple):
43		try:
44		_is_valid_range(exception, int)
45		except (TypeError, ValueError) as error:
46		log.warn(msg, error)
47		return False
48		elif not isinstance(exception, int):
49		error_msg = ('The elements must be of class int or tuple'
50		f' but they are: {type(exception)}')
51		log.warn(msg, error_msg)
52		return False
53	1	return True
54
55
56	1	class Main(KytosNApp):
57		"""Main class to be used by Kytos controller."""
58
59	1	def setup(self):
60		"""Replace the 'init' method for the KytosApp subclass.
61
62		The setup method is automatically called by the run method.
63		Users shouldn't call this method directly.
64		"""
65	1	log.debug("flow-manager starting")
66	1	self._flow_mods_sent = OrderedDict()
67	1	self._flow_mods_sent_max_size = FLOWS_DICT_MAX_SIZE
68	1	self.cookie_exception_range = []
69	1	self.tab_id_exception_range = []
70	1	if validate_input(CONSISTENCY_COOKIE_EXCEPTION_RANGE):
71	1	self.cookie_exception_range = CONSISTENCY_COOKIE_EXCEPTION_RANGE
72	1	if validate_input(CONSISTENCY_TABLE_ID_EXCEPTION_RANGE):
73	1	self.tab_id_exception_range = CONSISTENCY_TABLE_ID_EXCEPTION_RANGE
74
75		# Storehouse client to save and restore flow data:
76	1	self.storehouse = StoreHouse(self.controller)
77
78		# Format of stored flow data:
79		# {'flow_persistence': {'dpid_str': {'flow_list': [
80		# {'command': '<add\|delete>',
81		# 'flow': {flow_dict}}]}}}
82	1	self.stored_flows = {}
83	1	self.resent_flows = set()
84	1	if CONSISTENCY_INTERVAL > 0:
85	1	self.execute_as_loop(CONSISTENCY_INTERVAL)
86
87	1	def execute(self):
88		"""Run once on NApp 'start' or in a loop.
89
90		The execute method is called by the run method of KytosNApp class.
91		Users shouldn't call this method directly.
92		"""
93		self._load_flows()
94
95		if CONSISTENCY_INTERVAL > 0:
96		self.consistency_check()
97
98	1	def shutdown(self):
99		"""Shutdown routine of the NApp."""
100		log.debug("flow-manager stopping")
101
102	1	@listen_to('kytos/of_core.handshake.completed')
103		def resend_stored_flows(self, event):
104		"""Resend stored Flows."""
105	1	switch = event.content['switch']
106	1	dpid = str(switch.dpid)
107		# This can be a problem because this code is running a thread
108	1	if dpid in self.resent_flows:
109		log.debug(f'Flow already resent to the switch {dpid}')
110		return
111	1	if dpid in self.stored_flows:
112	1	flow_list = self.stored_flows[dpid]['flow_list']
113	1	for flow in flow_list:
114	1	command = flow['command']
115	1	flows_dict = {"flows": [flow['flow']]}
116	1	self._install_flows(command, flows_dict, [switch])
117	1	self.resent_flows.add(dpid)
118	1	log.info(f'Flows resent to Switch {dpid}')
119
120	1	@staticmethod
121		def is_exception(field, exceptions):
122		"""Check if the field are in the list of exceptions.
123
124		Returns True if the field is in the list of exceptions.
125		"""
126	1	for i in exceptions:
127	1	if isinstance(i, tuple):
128	1	begin_interval, end_interval = i
129	1	if begin_interval <= field <= end_interval:
130	1	return True
131	1	if isinstance(i, int):
132	1	if field == i:
133	1	return True
134	1	return False
135
136	1	def consistency_exception_check(self, flow):
137		"""Verify if the flow is in the exception range.
138
139		Check by `cookie` range and `table_id` range.
140		Returns True if the flow is in the exception list.
141		"""
142		# Check by cookie
143	1	if self.is_exception(flow.cookie, self.cookie_exception_range):
144	1	return True
145
146		# Check by `table_id`
147	1	if self.is_exception(flow.table_id, self.tab_id_exception_range):
148	1	return True
149	1	return False
150
151	1	def consistency_check(self):
152		"""Check the consistency of flows in each switch."""
153		switches = self.controller.switches.values()
154
155		for switch in switches:
156		# Check if a dpid is a key in 'stored_flows' dictionary
157		if switch.is_enabled():
158		self.check_storehouse_consistency(switch)
159
160		if switch.dpid in self.stored_flows:
161		self.check_switch_consistency(switch)
162
163	1	def check_switch_consistency(self, switch):
164		"""Check consistency of installed flows for a specific switch."""
165	1	dpid = switch.dpid
166
167		# Flows stored in storehouse
168	1	stored_flows = self.stored_flows[dpid]['flow_list']
169
170	1	serializer = FlowFactory.get_class(switch)
171
172	1	for stored_flow in stored_flows:
173	1	command = stored_flow['command']
174	1	stored_flow_obj = serializer.from_dict(stored_flow['flow'], switch)
175
176	1	flow = {'flows': [stored_flow['flow']]}
177
178	1	if stored_flow_obj not in switch.flows:
179	1	if command == 'add':
180	1	log.info('A consistency problem was detected in '
181		f'switch {dpid}.')
182	1	self._install_flows(command, flow, [switch])
183	1	log.info(f'Flow forwarded to switch {dpid} to be '
184		'installed.')
185	1	elif command == 'delete':
186	1	log.info('A consistency problem was detected in '
187		f'switch {dpid}.')
188	1	self._install_flows(command, flow, [switch])
189	1	log.info(f'Flow forwarded to switch {dpid} to be deleted.')
190
191	1	def check_storehouse_consistency(self, switch):
192		"""Check consistency of installed flows for a specific switch."""
193	1	dpid = switch.dpid
194
195	1	for installed_flow in switch.flows:
196
197		# Check if the flow are in the excluded flow list
198	1	if self.consistency_exception_check(installed_flow):
199	1	continue
200
201	1	if dpid not in self.stored_flows:
202		log.info('A consistency problem was detected in '
203		f'switch {dpid}.')
204		flow = {'flows': [installed_flow.as_dict()]}
205		command = 'delete'
206		self._install_flows(command, flow, [switch])
207		log.info(f'Flow forwarded to switch {dpid} to be deleted.')
208		else:
209	1	serializer = FlowFactory.get_class(switch)
210	1	stored_flows = self.stored_flows[dpid]['flow_list']
211	1	stored_flows_list = [serializer.from_dict(stored_flow['flow'],
212		switch)
213		for stored_flow in stored_flows]
214
215	1	if installed_flow not in stored_flows_list:
216	1	log.info('A consistency problem was detected in '
217		f'switch {dpid}.')
218	1	flow = {'flows': [installed_flow.as_dict()]}
219	1	command = 'delete'
220	1	self._install_flows(command, flow, [switch])
221	1	log.info(f'Flow forwarded to switch {dpid} to be deleted.')
222
223		# pylint: disable=attribute-defined-outside-init
224	1	def _load_flows(self):
225		"""Load stored flows."""
226	1	try:
227	1	data = self.storehouse.get_data()['flow_persistence']
228	1	if 'id' in data:
229		del data['id']
230	1	self.stored_flows = data
231		except (KeyError, FileNotFoundError) as error:
232		log.debug(f'There are no flows to load: {error}')
233		else:
234	1	log.info('Flows loaded.')
235
236	1	def _store_changed_flows(self, command, flow, switch):
237		"""Store changed flows.
238
239		Args:
240		command: Flow command to be installed
241		flow: Flows to be stored
242		switch: Switch target
243		"""
244	1	stored_flows_box = self.stored_flows.copy()
245		# if the flow has a destination dpid it can be stored.
246	1	if not switch:
247		log.info('The Flow cannot be stored, the destination switch '
248		f'have not been specified: {switch}')
249		return
250	1	installed_flow = {}
251	1	flow_list = []
252	1	installed_flow['command'] = command
253	1	installed_flow['flow'] = flow
254
255	1	serializer = FlowFactory.get_class(switch)
256	1	installed_flow_obj = serializer.from_dict(flow, switch)
257
258	1	if switch.id not in stored_flows_box:
259		# Switch not stored, add to box.
260	1	flow_list.append(installed_flow)
261	1	stored_flows_box[switch.id] = {'flow_list': flow_list}
262		else:
263	1	stored_flows = stored_flows_box[switch.id].get('flow_list', [])
264		# Check if flow already stored
265	1	for stored_flow in stored_flows:
266	1	stored_flow_obj = serializer.from_dict(stored_flow['flow'],
267		switch)
268	1	if installed_flow_obj == stored_flow_obj:
269	1	if stored_flow['command'] == installed_flow['command']:
270		log.debug('Data already stored.')
271		return
272		# Flow with inconsistency in "command" fields : Remove the
273		# old instruction. This happens when there is a stored
274		# instruction to install the flow, but the new instruction
275		# is to remove it. In this case, the old instruction is
276		# removed and the new one is stored.
277	1	stored_flow['command'] = installed_flow.get('command')
278	1	stored_flows.remove(stored_flow)
279	1	break
280
281	1	stored_flows.append(installed_flow)
282	1	stored_flows_box[switch.id]['flow_list'] = stored_flows
283
284	1	stored_flows_box['id'] = 'flow_persistence'
285	1	self.storehouse.save_flow(stored_flows_box)
286	1	del stored_flows_box['id']
287	1	self.stored_flows = stored_flows_box.copy()
288
289	1	@rest('v2/flows')
290	1	@rest('v2/flows/<dpid>')
291	1	def list(self, dpid=None):
292		"""Retrieve all flows from a switch identified by dpid.
293
294		If no dpid is specified, return all flows from all switches.
295		"""
296	1	if dpid is None:
297	1	switches = self.controller.switches.values()
298		else:
299	1	switches = [self.controller.get_switch_by_dpid(dpid)]
300
301	1	switch_flows = {}
302
303	1	for switch in switches:
304	1	flows_dict = [flow.as_dict() for flow in switch.flows]
305	1	switch_flows[switch.dpid] = {'flows': flows_dict}
306
307	1	return jsonify(switch_flows)
308
309	1	@rest('v2/flows', methods=['POST'])
310	1	@rest('v2/flows/<dpid>', methods=['POST'])
311	1	def add(self, dpid=None):
312		"""Install new flows in the switch identified by dpid.
313
314		If no dpid is specified, install flows in all switches.
315		"""
316	1	return self._send_flow_mods_from_request(dpid, "add")
317
318	1	@rest('v2/delete', methods=['POST'])
319	1	@rest('v2/delete/<dpid>', methods=['POST'])
320	1	@rest('v2/flows', methods=['DELETE'])
321	1	@rest('v2/flows/<dpid>', methods=['DELETE'])
322	1	def delete(self, dpid=None):
323		"""Delete existing flows in the switch identified by dpid.
324
325		If no dpid is specified, delete flows from all switches.
326		"""
327	1	return self._send_flow_mods_from_request(dpid, "delete")
328
329	1	def _get_all_switches_enabled(self):
330		"""Get a list of all switches enabled."""
331	1	switches = self.controller.switches.values()
332	1	return [switch for switch in switches if switch.is_enabled()]
333
334	1	def _send_flow_mods_from_request(self, dpid, command, flows_dict=None):
335		"""Install FlowsMods from request."""
336	1	if flows_dict is None:
337	1	flows_dict = request.get_json()
338	1	if flows_dict is None:
339	1	return jsonify({"response": 'flows dict is none.'}), 404
340
341	1	if dpid:
342	1	switch = self.controller.get_switch_by_dpid(dpid)
343	1	if not switch:
344	1	return jsonify({"response": 'dpid not found.'}), 404
345	1	elif switch.is_enabled() is False:
346	1	if command == "delete":
347	1	self._install_flows(command, flows_dict, [switch])
348		else:
349	1	return jsonify({"response": 'switch is disabled.'}), 404
350		else:
351	1	self._install_flows(command, flows_dict, [switch])
352		else:
353	1	self._install_flows(command, flows_dict,
354		self._get_all_switches_enabled())
355
356	1	return jsonify({"response": "FlowMod Messages Sent"})
357
358	1	def _install_flows(self, command, flows_dict, switches=[]):
359		"""Execute all procedures to install flows in the switches.
360
361		Args:
362		command: Flow command to be installed
363		flows_dict: Dictionary with flows to be installed in the switches.
364		switches: A list of switches
365		"""
366	1	for switch in switches:
367	1	serializer = FlowFactory.get_class(switch)
368	1	flows = flows_dict.get('flows', [])
369	1	for flow_dict in flows:
370	1	flow = serializer.from_dict(flow_dict, switch)
371	1	if command == "delete":
372		flow_mod = flow.as_of_delete_flow_mod()
373	1	elif command == "add":
374	1	flow_mod = flow.as_of_add_flow_mod()
375		else:
376		raise InvalidCommandError
377	1	self._send_flow_mod(flow.switch, flow_mod)
378	1	self._add_flow_mod_sent(flow_mod.header.xid, flow, command)
379
380	1	self._send_napp_event(switch, flow, command)
381	1	self._store_changed_flows(command, flow_dict, switch)
382
383	1	def _add_flow_mod_sent(self, xid, flow, command):
384		"""Add the flow mod to the list of flow mods sent."""
385	1	if len(self._flow_mods_sent) >= self._flow_mods_sent_max_size:
386		self._flow_mods_sent.popitem(last=False)
387	1	self._flow_mods_sent[xid] = (flow, command)
388
389	1	def _send_flow_mod(self, switch, flow_mod):
390	1	event_name = 'kytos/flow_manager.messages.out.ofpt_flow_mod'
391
392	1	content = {'destination': switch.connection,
393		'message': flow_mod}
394
395	1	event = KytosEvent(name=event_name, content=content)
396	1	self.controller.buffers.msg_out.put(event)
397
398	1	def _send_napp_event(self, switch, flow, command, **kwargs):
399		"""Send an Event to other apps informing about a FlowMod."""
400	1	if command == 'add':
401	1	name = 'kytos/flow_manager.flow.added'
402	1	elif command == 'delete':
403	1	name = 'kytos/flow_manager.flow.removed'
404	1	elif command == 'error':
405	1	name = 'kytos/flow_manager.flow.error'
406		else:
407		raise InvalidCommandError
408	1	content = {'datapath': switch,
409		'flow': flow}
410	1	content.update(kwargs)
411	1	event_app = KytosEvent(name, content)
412	1	self.controller.buffers.app.put(event_app)
413
414	1	@listen_to('..of_core..ofpt_error')
415		def handle_errors(self, event):
416		"""Receive OpenFlow error and send a event.
417
418		The event is sent only if the error is related to a request made
419		by flow_manager.
420		"""
421	1	message = event.content["message"]
422
423	1	connection = event.source
424	1	switch = connection.switch
425
426	1	xid = message.header.xid.value
427	1	error_type = message.error_type
428	1	error_code = message.code
429	1	error_data = message.data.pack()
430
431		# Get the packet responsible for the error
432	1	error_packet = connection.protocol.unpack(error_data)
433
434	1	if message.code == BadActionCode.OFPBAC_BAD_OUT_PORT:
435		actions = []
436		if hasattr(error_packet, 'actions'):
437		# Get actions from the flow mod (OF 1.0)
438		actions = error_packet.actions
439		else:
440		# Get actions from the list of flow mod instructions (OF 1.3)
441		for instruction in error_packet.instructions:
442		actions.extend(instruction.actions)
443
444		for action in actions:
445		iface = switch.get_interface_by_port_no(action.port)
446
447		# Set interface to drop packets forwarded to it
448		if iface:
449		iface.config = PortConfig.OFPPC_NO_FWD
450
451	1	try:
452	1	flow, error_command = self._flow_mods_sent[xid]
453		except KeyError:
454		pass
455		else:
456	1	self._send_napp_event(flow.switch, flow, 'error',
457		error_command=error_command,
458		error_type=error_type, error_code=error_code)
459

kytos / flow_manager

Pull Request — master (#112)

build.main.Main.check_switch_consistency() A

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