build.main.Main._send_napp_event() - 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 2021-02-25 15:23 UTC

build.main.Main._send_napp_event() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	15
Code Lines	13

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	11
CRAP Score	4.0092

Importance

Changes

Metric	Value
eloc	13
dl	0
loc	15
rs	9.75
c	0
b	0
f	0
ccs	11
cts	12
cp	0.9167
cc	4
nop	5
crap	4.0092

"""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 range is not well formatted: {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 = 'Consistency exception is not well formatted: %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
        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 in_range(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.in_range(flow.cookie, self.cookie_exception_range):
            return True

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

kytos / flow_manager

Pull Request — master (#112)

build.main.Main._send_napp_event() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like