build.main.Main.shutdown() - Code Metrics - Inspection of "feat: Remove automate in main" - kytos-ng/sdntrace_cp - Measure and Improve Code Quality continuously with Scrutinizer

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Pull Request — master (#95)

unknown

created 2023-05-01 21:01 UTC

build.main.Main.shutdown() A

↳ Parent: build.main

Complexity

Conditions

Size

Total Lines	2
Code Lines	1

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	1
CRAP Score	1

Importance

Changes

Metric	Value
cc	1
eloc	1
nop	1
dl	0
loc	2
ccs	1
cts	1
cp	1
crap	1
rs	10
c	0
b	0
f	0

"""Main module of amlight/sdntrace_cp Kytos Network Application.

Run tracepaths on OpenFlow in the Control Plane
"""

import ipaddress
import pathlib
from datetime import datetime

import requests
from flask import jsonify
from kytos.core import KytosNApp, log, rest
from kytos.core.helpers import load_spec, validate_openapi
from napps.amlight.sdntrace_cp.utils import (convert_entries,
                                             convert_list_entries,
                                             find_endpoint, get_stored_flows,
                                             match_field_dl_vlan, prepare_json)


class Main(KytosNApp):
    """Main class of amlight/sdntrace_cp NApp.

    This application gets the list of flows from the switches
    and uses it to trace paths without using the data plane.
    """

    spec = load_spec(pathlib.Path(__file__).parent / "openapi.yml")

    def setup(self):
        """Replace the '__init__' method for the KytosNApp subclass.

        The setup method is automatically called by the controller when your
        application is loaded.

        """
        log.info("Starting Kytos SDNTrace CP App!")

    def execute(self):
        """This method is executed right after the setup method execution.

        You can also use this method in loop mode if you add to the above setup
        method a line like the following example:

            self.execute_as_loop(30)  # 30-second interval.
        """

    def shutdown(self):
        """This method is executed when your napp is unloaded.

        If you have some cleanup procedure, insert it here.
        """

    @rest('/v1/trace', methods=['PUT'])
    @validate_openapi(spec)
    def trace(self, data):
        """Trace a path."""
        result = []
        entries = convert_entries(data)
        try:
            stored_flows = get_stored_flows()
        except requests.RequestException:
            result = []
        else:
            result = self.tracepath(entries, stored_flows)
        return jsonify(prepare_json(result))

    @rest('/v1/traces', methods=['PUT'])
    @validate_openapi(spec)
    def get_traces(self, data):
        """For bulk requests."""
        entries = convert_list_entries(data)
        results = []
        try:
            stored_flows = get_stored_flows()
        except requests.RequestException:
            return jsonify({'result': []})
        for entry in entries:
            results.append(self.tracepath(entry, stored_flows))
        temp = prepare_json(results)
        return jsonify(temp)

    def tracepath(self, entries, stored_flows):
        """Trace a path for a packet represented by entries."""
        # pylint: disable=too-many-branches
        trace_result = []
        trace_type = 'starting'
        do_trace = True
        while do_trace:
            if 'dpid' not in entries or 'in_port' not in entries:
                break
            trace_step = {'in': {'dpid': entries['dpid'],
                                 'port': entries['in_port'],
                                 'time': str(datetime.now()),
                                 'type': trace_type}}
            if 'dl_vlan' in entries:
                trace_step['in'].update({'vlan': entries['dl_vlan'][-1]})

            switch = self.controller.get_switch_by_dpid(entries['dpid'])
            if not switch:
                trace_step['in']['type'] = 'last'
                trace_result.append(trace_step)
                break
            result = self.trace_step(switch, entries, stored_flows)
            if result:
                out = {'port': result['out_port']}
                if 'dl_vlan' in result['entries']:
                    out.update({'vlan': result['entries']['dl_vlan'][-1]})
                trace_step.update({
                    'out': out
                })
                if 'dpid' in result:
                    next_step = {'dpid': result['dpid'],
                                 'port': result['in_port']}
                    entries = result['entries']
                    entries['dpid'] = result['dpid']
                    entries['in_port'] = result['in_port']
                    if self.has_loop(next_step, trace_result):
                        trace_step['in']['type'] = 'loop'
                        do_trace = False
                    else:
                        trace_type = 'intermediary'
                else:
                    trace_step['in']['type'] = 'last'
                    do_trace = False
            else:
                trace_step['in']['type'] = 'incomplete'
                do_trace = False
            if 'out' in trace_step and trace_step['out']:
                if self.check_loop_trace_step(trace_step, trace_result):
                    do_trace = False
            trace_result.append(trace_step)
        return trace_result

    @staticmethod
    def check_loop_trace_step(trace_step, trace_result):
        """Check if there is a loop in the trace and add the step."""
        # outgoing interface is the same as the input interface
        if not trace_result and \
                trace_step['in']['type'] == 'last' and \
                trace_step['in']['port'] == trace_step['out']['port']:
            trace_step['in']['type'] = 'loop'
            return True
        if trace_result and \
                trace_result[0]['in']['dpid'] == trace_step['in']['dpid'] and \
                trace_result[0]['in']['port'] == trace_step['out']['port']:
            trace_step['in']['type'] = 'loop'
            return True
        return False

    @staticmethod
    def has_loop(trace_step, trace_result):
        """Check if there is a loop in the trace result."""
        for trace in trace_result:
            if trace['in']['dpid'] == trace_step['dpid'] and \
                            trace['in']['port'] == trace_step['port']:
                return True
        return False

    def trace_step(self, switch, entries, stored_flows):
        """Perform a trace step.

        Match the given fields against the switch's list of flows."""
        flow, entries, port = self.match_and_apply(
                                                    switch,
                                                    entries,
                                                    stored_flows
                                                )

        if not flow or not port:
            return None

        endpoint = find_endpoint(switch, port)
        if endpoint is None:
            log.warning(f"Port {port} not found on switch {switch}")
            return None
        endpoint = endpoint['endpoint']
        if endpoint is None:
            return {'out_port': port,
                    'entries': entries}

        return {'dpid': endpoint.switch.dpid,
                'in_port': endpoint.port_number,
                'out_port': port,
                'entries': entries}

    @classmethod
    def do_match(cls, flow, args):
        """Match a packet against this flow (OF1.3)."""
        # pylint: disable=consider-using-dict-items
        # pylint: disable=too-many-return-statements
        if ('match' not in flow['flow']) or (len(flow['flow']['match']) == 0):
            return False
        for name in flow['flow']['match']:
            field_flow = flow['flow']['match'][name]
            if name == 'dl_vlan':
                field = args.get(name)
                if field:
                    field = field[-1]
                if not match_field_dl_vlan(field, field_flow):
                    return False
                continue
            if name not in args:
                return False
            field = args[name]
            if name not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
                if field_flow != field:
                    return False
            else:
                packet_ip = int(ipaddress.ip_address(field))
                ip_addr = flow['flow']['match'][name]
                if packet_ip & ip_addr.netmask != ip_addr.address:
                    return False
        return flow

    def match_flows(self, switch, args, stored_flows, many=True):
        # pylint: disable=bad-staticmethod-argument
        """
        Match the packet in request against the stored flows from flow_manager.
        Try the match with each flow, in other. If many is True, tries the
        match with all flows, if False, tries until the first match.
        :param args: packet data
        :param many: Boolean, indicating whether to continue after matching the
                first flow or not
        :return: If many, the list of matched flows, or the matched flow
        """
        if switch.dpid not in stored_flows:
            return None
        response = []
        if switch.dpid not in stored_flows:
            return None
        try:
            for flow in stored_flows[switch.dpid]:
                match = Main.do_match(flow, args)
                if match:
                    if many:
                        response.append(match)
                    else:
                        response = match
                        break
        except AttributeError:
            return None
        if not many and isinstance(response, list):
            return None
        return response

    # pylint: disable=redefined-outer-name
    def match_and_apply(self, switch, args, stored_flows):
        # pylint: disable=bad-staticmethod-argument
        """Match flows and apply actions.
        Match given packet (in args) against
        the stored flows (from flow_manager) and,
        if a match flow is found, apply its actions."""
        flow = self.match_flows(switch, args, stored_flows, False)
        port = None
        actions = []
        # pylint: disable=too-many-nested-blocks
        if not flow or switch.ofp_version != '0x04':
            return flow, args, port
        if 'actions' in flow['flow']:
            actions = flow['flow']['actions']
        for action in actions:
            action_type = action['action_type']
            if action_type == 'output':
                port = action['port']
            if action_type == 'push_vlan':
                if 'dl_vlan' not in args:
                    args['dl_vlan'] = []
                args['dl_vlan'].append(0)
            if action_type == 'pop_vlan':
                if 'dl_vlan' in args:
                    args['dl_vlan'].pop()
                    if len(args['dl_vlan']) == 0:
                        del args['dl_vlan']
            if action_type == 'set_vlan':
                args['dl_vlan'][-1] = action['vlan_id']
        return flow, args, port


1		"""Main module of amlight/sdntrace_cp Kytos Network Application.
2
3		Run tracepaths on OpenFlow in the Control Plane
4		"""
5
6	1	import ipaddress
7	1	import pathlib
8	1	from datetime import datetime
9
10	1	import requests
11	1	from flask import jsonify
12	1	from kytos.core import KytosNApp, log, rest
13	1	from kytos.core.helpers import load_spec, validate_openapi
14	1	from napps.amlight.sdntrace_cp.utils import (convert_entries,
15		convert_list_entries,
16		find_endpoint, get_stored_flows,
17		match_field_dl_vlan, prepare_json)
18
19
20	1	class Main(KytosNApp):
21		"""Main class of amlight/sdntrace_cp NApp.
22
23		This application gets the list of flows from the switches
24		and uses it to trace paths without using the data plane.
25		"""
26
27	1	spec = load_spec(pathlib.Path(__file__).parent / "openapi.yml")
28
29	1	def setup(self):
30		"""Replace the '__init__' method for the KytosNApp subclass.
31
32		The setup method is automatically called by the controller when your
33		application is loaded.
34
35		"""
36	1	log.info("Starting Kytos SDNTrace CP App!")
37
38	1	def execute(self):
39		"""This method is executed right after the setup method execution.
40
41		You can also use this method in loop mode if you add to the above setup
42		method a line like the following example:
43
44		self.execute_as_loop(30) # 30-second interval.
45		"""
46
47	1	def shutdown(self):
48		"""This method is executed when your napp is unloaded.
49
50		If you have some cleanup procedure, insert it here.
51		"""
52
53	1	@rest('/v1/trace', methods=['PUT'])
54	1	@validate_openapi(spec)
55	1	def trace(self, data):
56		"""Trace a path."""
57	1	result = []
58	1	entries = convert_entries(data)
59	1	try:
60	1	stored_flows = get_stored_flows()
61		except requests.RequestException:
62		result = []
63		else:
64	1	result = self.tracepath(entries, stored_flows)
65	1	return jsonify(prepare_json(result))
66
67	1	@rest('/v1/traces', methods=['PUT'])
68	1	@validate_openapi(spec)
69	1	def get_traces(self, data):
70		"""For bulk requests."""
71	1	entries = convert_list_entries(data)
72	1	results = []
73	1	try:
74	1	stored_flows = get_stored_flows()
75		except requests.RequestException:
76		return jsonify({'result': []})
77	1	for entry in entries:
78	1	results.append(self.tracepath(entry, stored_flows))
79	1	temp = prepare_json(results)
80	1	return jsonify(temp)
81
82	1	def tracepath(self, entries, stored_flows):
83		"""Trace a path for a packet represented by entries."""
84		# pylint: disable=too-many-branches
85	1	trace_result = []
86	1	trace_type = 'starting'
87	1	do_trace = True
88	1	while do_trace:
89	1	if 'dpid' not in entries or 'in_port' not in entries:
90		break
91	1	trace_step = {'in': {'dpid': entries['dpid'],
92		'port': entries['in_port'],
93		'time': str(datetime.now()),
94		'type': trace_type}}
95	1	if 'dl_vlan' in entries:
96	1	trace_step['in'].update({'vlan': entries['dl_vlan'][-1]})
97
98	1	switch = self.controller.get_switch_by_dpid(entries['dpid'])
99	1	if not switch:
100	1	trace_step['in']['type'] = 'last'
101	1	trace_result.append(trace_step)
102	1	break
103	1	result = self.trace_step(switch, entries, stored_flows)
104	1	if result:
105	1	out = {'port': result['out_port']}
106	1	if 'dl_vlan' in result['entries']:
107	1	out.update({'vlan': result['entries']['dl_vlan'][-1]})
108	1	trace_step.update({
109		'out': out
110		})
111	1	if 'dpid' in result:
112	1	next_step = {'dpid': result['dpid'],
113		'port': result['in_port']}
114	1	entries = result['entries']
115	1	entries['dpid'] = result['dpid']
116	1	entries['in_port'] = result['in_port']
117	1	if self.has_loop(next_step, trace_result):
118	1	trace_step['in']['type'] = 'loop'
119	1	do_trace = False
120		else:
121	1	trace_type = 'intermediary'
122		else:
123	1	trace_step['in']['type'] = 'last'
124	1	do_trace = False
125		else:
126	1	trace_step['in']['type'] = 'incomplete'
127	1	do_trace = False
128	1	if 'out' in trace_step and trace_step['out']:
129	1	if self.check_loop_trace_step(trace_step, trace_result):
130	1	do_trace = False
131	1	trace_result.append(trace_step)
132	1	return trace_result
133
134	1	@staticmethod
135	1	def check_loop_trace_step(trace_step, trace_result):
136		"""Check if there is a loop in the trace and add the step."""
137		# outgoing interface is the same as the input interface
138	1	if not trace_result and \
139		trace_step['in']['type'] == 'last' and \
140		trace_step['in']['port'] == trace_step['out']['port']:
141	1	trace_step['in']['type'] = 'loop'
142	1	return True
143	1	if trace_result and \
144		trace_result[0]['in']['dpid'] == trace_step['in']['dpid'] and \
145		trace_result[0]['in']['port'] == trace_step['out']['port']:
146	1	trace_step['in']['type'] = 'loop'
147	1	return True
148	1	return False
149
150	1	@staticmethod
151	1	def has_loop(trace_step, trace_result):
152		"""Check if there is a loop in the trace result."""
153	1	for trace in trace_result:
154	1	if trace['in']['dpid'] == trace_step['dpid'] and \
155		trace['in']['port'] == trace_step['port']:
156	1	return True
157	1	return False
158
159	1	def trace_step(self, switch, entries, stored_flows):
160		"""Perform a trace step.
161
162		Match the given fields against the switch's list of flows."""
163	1	flow, entries, port = self.match_and_apply(
164		switch,
165		entries,
166		stored_flows
167		)
168
169	1	if not flow or not port:
170	1	return None
171
172	1	endpoint = find_endpoint(switch, port)
173	1	if endpoint is None:
174		log.warning(f"Port {port} not found on switch {switch}")
175		return None
176	1	endpoint = endpoint['endpoint']
177	1	if endpoint is None:
178	1	return {'out_port': port,
179		'entries': entries}
180
181	1	return {'dpid': endpoint.switch.dpid,
182		'in_port': endpoint.port_number,
183		'out_port': port,
184		'entries': entries}
185
186	1	@classmethod
187	1	def do_match(cls, flow, args):
188		"""Match a packet against this flow (OF1.3)."""
189		# pylint: disable=consider-using-dict-items
190		# pylint: disable=too-many-return-statements
191	1	if ('match' not in flow['flow']) or (len(flow['flow']['match']) == 0):
192	1	return False
193	1	for name in flow['flow']['match']:
194	1	field_flow = flow['flow']['match'][name]
195	1	if name == 'dl_vlan':
196	1	field = args.get(name)
197	1	if field:
198	1	field = field[-1]
199	1	if not match_field_dl_vlan(field, field_flow):
200	1	return False
201		continue
202	1	if name not in args:
203		return False
204	1	field = args[name]
205	1	if name not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
206	1	if field_flow != field:
207	1	return False
208		else:
209		packet_ip = int(ipaddress.ip_address(field))
210		ip_addr = flow['flow']['match'][name]
211		if packet_ip & ip_addr.netmask != ip_addr.address:
212		return False
213	1	return flow
214
215	1	def match_flows(self, switch, args, stored_flows, many=True):
216		# pylint: disable=bad-staticmethod-argument
217		"""
218		Match the packet in request against the stored flows from flow_manager.
219		Try the match with each flow, in other. If many is True, tries the
220		match with all flows, if False, tries until the first match.
221		:param args: packet data
222		:param many: Boolean, indicating whether to continue after matching the
223		first flow or not
224		:return: If many, the list of matched flows, or the matched flow
225		"""
226	1	if switch.dpid not in stored_flows:
227		return None
228	1	response = []
229	1	if switch.dpid not in stored_flows:
230		return None
231	1	try:
232	1	for flow in stored_flows[switch.dpid]:
233	1	match = Main.do_match(flow, args)
234	1	if match:
235	1	if many:
236		response.append(match)
237		else:
238	1	response = match
239	1	break
240		except AttributeError:
241		return None
242	1	if not many and isinstance(response, list):
243	1	return None
244	1	return response
245
246		# pylint: disable=redefined-outer-name
247	1	def match_and_apply(self, switch, args, stored_flows):
248		# pylint: disable=bad-staticmethod-argument
249		"""Match flows and apply actions.
250		Match given packet (in args) against
251		the stored flows (from flow_manager) and,
252		if a match flow is found, apply its actions."""
253	1	flow = self.match_flows(switch, args, stored_flows, False)
254	1	port = None
255	1	actions = []
256		# pylint: disable=too-many-nested-blocks
257	1	if not flow or switch.ofp_version != '0x04':
258	1	return flow, args, port
259	1	if 'actions' in flow['flow']:
260	1	actions = flow['flow']['actions']
261	1	for action in actions:
262	1	action_type = action['action_type']
263	1	if action_type == 'output':
264	1	port = action['port']
265	1	if action_type == 'push_vlan':
266	1	if 'dl_vlan' not in args:
267		args['dl_vlan'] = []
268	1	args['dl_vlan'].append(0)
269	1	if action_type == 'pop_vlan':
270	1	if 'dl_vlan' in args:
271	1	args['dl_vlan'].pop()
272	1	if len(args['dl_vlan']) == 0:
273	1	del args['dl_vlan']
274	1	if action_type == 'set_vlan':
275	1	args['dl_vlan'][-1] = action['vlan_id']
276		return flow, args, port
277

kytos-ng / sdntrace_cp

Pull Request — master (#95)

build.main.Main.shutdown() A

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