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

Passed

Pull Request — master (#112)

by Carlos

created 2021-02-22 18:47 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_EXCEPTION_COOKIE_RANGE,
                       CONSISTENCY_EXCEPTION_TABLE_ID_RANGE,
                       CONSISTENCY_INTERVAL, FLOWS_DICT_MAX_SIZE)


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.exception_cookies_range = CONSISTENCY_EXCEPTION_COOKIE_RANGE
        self.exception_table_ids_range = CONSISTENCY_EXCEPTION_TABLE_ID_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}')

    def is_ignored(self, flow):
        """Verify if the flow are in the exception range.

        Check by `cookie` range and `table_id` range.
        """
        # Check by cookie
        if len(self.exception_cookies_range) == 2:
            begin_cookie = self.exception_cookies_range[0]
            end_cookie = self.exception_cookies_range[1]
            if flow.cookie >= begin_cookie and flow.cookie <= end_cookie:
                return True

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

kytos / flow_manager

Pull Request — master (#112)

build.main.Main.check_switch_consistency() A

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