build.main.cast_fields() - Code Metrics - Inspection of "Add support to install or remove flows on switches..." - kytos/flow_manager - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#129)

by Carlos

created 2021-05-19 17:51 UTC

build.main.cast_fields() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	8
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	6
CRAP Score	3.0261

Importance

Changes

Metric	Value
cc	3
eloc	7
nop	1
dl	0
loc	8
ccs	6
cts	7
cp	0.8571
crap	3.0261
rs	10
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 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 CONSISTENCY_INTERVAL, 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()
        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."""
        # if consistency check is enabled, it should take care of this
        if CONSISTENCY_INTERVAL >= 0:
            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}')

    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}.')
                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)]

        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)

    @listen_to('kytos.flow_manager.flows.(install|delete)')
    def event_add_flow(self, event):
        """Install or delete flows in the switches through events.

        Install or delete Flow of switches identified by dpid.
        """
        try:
            dpid = event.content['dpid']
            flow_dict = event.content['flow_dict']
            command = event.content['command']
        except KeyError as error:
            log.error("Error getting fields to install or remove "
                      f"Flows: {error}")
            return
        try:
            switch = self.controller.get_switch_by_dpid(dpid)
            self._install_flows(command, flow_dict, [switch])
        except InvalidCommandError as error:
            log.error("Error installing or deleting Flow through"
                      f" Kytos Event: {error}")

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

kytos / flow_manager

Pull Request — master (#129)

build.main.cast_fields() A

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