build.main.Main.check_storehouse_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 20:53 UTC

build.main.Main.check_storehouse_consistency() B

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	31
Code Lines	22

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	15
CRAP Score	5.3906

Importance

Changes

Metric	Value
cc	5
eloc	22
nop	2
dl	0
loc	31
rs	8.8853
c	0
b	0
f	0
ccs	15
cts	20
cp	0.75
crap	5.3906

"""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)


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.cookies_exception_range = CONSISTENCY_COOKIE_EXCEPTION_RANGE
        self.table_ids_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}')

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

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

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

kytos / flow_manager

Pull Request — master (#112)

build.main.Main.check_storehouse_consistency() B

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