build.match.match_flows() - Code Metrics - Inspection of "Add support for non-strict exclusion in the consis..." - kytos/flow_manager - Measure and Improve Code Quality continuously with Scrutinizer

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Pull Request — master (#117)

by Carlos

created 2021-04-06 15:42 UTC

build.match.match_flows() A

↳ Parent: build.match

Complexity

Conditions

Size

Total Lines	14
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	1
CRAP Score	1.2963

Importance

Changes

Metric	Value
cc	1
eloc	3
nop	3
dl	0
loc	14
ccs	1
cts	3
cp	0.3333
crap	1.2963
rs	10
c	0
b	0
f	0

"""Switch match."""

import ipaddress

from pyof.v0x01.common.flow_match import FlowWildCards

IPV4_ETH_TYPE = 2048


def format_request(request):
    """Format user request to match function format."""
    args = {}
    for key, value in request.items():
        args[key] = value
    return args


def do_match(flow_to_install, version, stored_flow_dict):
    """Match a packet against this flow."""
    if version == 0x01:
        return match10(stored_flow_dict, flow_to_install)
    elif version == 0x04:
        return match13_no_strict(flow_to_install, stored_flow_dict)
    raise NotImplementedError(f'Unsupported OpenFlow version {version}')


def _get_match_fields(flow_dict):
    """Generate match fields."""
    match_fields = {}
    if 'match' in flow_dict:
        for key, value in flow_dict['match'].items():
            match_fields[key] = value
    return match_fields


# pylint: disable=too-many-return-statements, too-many-statements, R0912
def _match_ipv4(match_fields, args, wildcards):
    """Match IPV4."""
    if not match_fields['eth_type'] == IPV4_ETH_TYPE:
        return False
    flow_ip_int = int(ipaddress.IPv4Address(match_fields.get('ipv4_src')))
    if flow_ip_int != 0:
        mask = (wildcards
                & FlowWildCards.OFPFW_NW_SRC_MASK) >> \
                FlowWildCards.OFPFW_NW_SRC_SHIFT
        if mask > 32:
            mask = 32
        if mask != 32 and 'ipv4_src' not in args:
            return False
        mask = (0xffffffff << mask) & 0xffffffff
        ip_int = int(ipaddress.IPv4Address(args.get('ipv4_src')))
        if ip_int & mask != flow_ip_int & mask:
            return False

    flow_ip_int = int(ipaddress.IPv4Address(match_fields['ipv4_dst']))
    if flow_ip_int != 0:
        mask = (wildcards
                & FlowWildCards.OFPFW_NW_DST_MASK) >> \
                FlowWildCards.OFPFW_NW_DST_SHIFT
        if mask > 32:
            mask = 32
        if mask != 32 and 'ipv4_dst' not in args:
            return False
        mask = (0xffffffff << mask) & 0xffffffff
        ip_int = int(ipaddress.IPv4Address(args.get('ipv4_dst')))
        if ip_int & mask != flow_ip_int & mask:
            return False
    if not wildcards & FlowWildCards.OFPFW_NW_TOS:
        if 'ip_tos' not in args:
            return False
        if match_fields.get('ip_tos') != int(args.get('ip_tos')):
            return False
    if not wildcards & FlowWildCards.OFPFW_NW_PROTO:
        if 'ip_proto' not in args:
            return False
        if match_fields.get('ip_proto') != int(args.get('ip_proto')):
            return False
    if not wildcards & FlowWildCards.OFPFW_TP_SRC:
        if 'tp_src' not in args:
            return False
        if match_fields.get('tcp_src') != int(args.get('tp_src')):
            return False
    if not wildcards & FlowWildCards.OFPFW_TP_DST:
        if 'tp_dst' not in args:
            return False
        if match_fields.get('tcp_dst') != int(args.get('tp_dst')):
            return False
    return True


# pylint: disable=too-many-return-statements, too-many-statements, R0912
def match10(flow_dict, args):
    """Match a packet against this flow (OF1.0)."""
    match_fields = _get_match_fields(flow_dict)
    wildcards = match_fields.get('wildcards')
    if not wildcards & FlowWildCards.OFPFW_IN_PORT:
        if 'in_port' not in args:
            return False
        if match_fields.get('in_port') != int(args.get('in_port')):
            return False
    if not wildcards & FlowWildCards.OFPFW_DL_VLAN_PCP:
        if 'vlan_pcp' not in args:
            return False
        if match_fields.get('vlan_pcp') != int(args.get('vlan_pcp')):
            return False
    if not wildcards & FlowWildCards.OFPFW_DL_VLAN:
        if 'vlan_vid' not in args:
            return False
        if match_fields.get('vlan_vid') != args.get('vlan_vid')[-1]:
            return False
    if not wildcards & FlowWildCards.OFPFW_DL_SRC:
        if 'eth_src' not in args:
            return False
        if match_fields.get('eth_src') != args.get('eth_src'):
            return False
    if not wildcards & FlowWildCards.OFPFW_DL_DST:
        if 'eth_dst' not in args:
            return False
        if match_fields.get('eth_dst') != args.get('eth_dst'):
            return False
    if not wildcards & FlowWildCards.OFPFW_DL_TYPE:
        if 'eth_type' not in args:
            return False
        if match_fields.get('eth_type') != int(args.get('eth_type')):
            return False
    if not _match_ipv4(match_fields, args, wildcards):
        return False
    return flow_dict

    # def match13(self, args):
    #     """Match a packet against this flow (OF1.3)."""
    #     for name in self.match:
    #         if name not in args:
    #             return False
    #         if name == 'vlan_vid':
    #             field = args[name][-1]
    #         else:
    #             field = args[name]
    #         if name not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
    #             if self.match[name].value != field:
    #                 return False
    #         else:
    #             packet_ip = int(ipaddress.ip_address(field))
    #             ip_addr = self.match[name].value
    #             if packet_ip & ip_addr.netmask != ip_addr.address:
    #                 return False
    #     return self


def match13_no_strict(flow_to_install, stored_flow_dict):
    """Match a packet againts the stored flow (OF 1.3).

    Return the flow if any fields match, otherwise, return False.
    """
    if flow_to_install.get('cookie_mask') and 'cookie' in stored_flow_dict:
        cookie = flow_to_install['cookie_mask'] & flow_to_install['cookie']
        if cookie == stored_flow_dict['cookie']:
            return stored_flow_dict
        return False

    if 'match' not in flow_to_install:
        return False

    for key, value in flow_to_install.get('match').items():
        if 'match' not in stored_flow_dict:
            return False
        if key not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
            if value == stored_flow_dict['match'].get(key):
                return stored_flow_dict
        else:
            field = flow_to_install.get(key)
            packet_ip = int(ipaddress.ip_address(field))
            ip_addr = value
            if packet_ip & ip_addr.netmask == ip_addr.address:
                return stored_flow_dict

    return False


def match_flows(flow_to_install, version, stored_flow_dict):
    # pylint: disable=bad-staticmethod-argument
    """
    Match the packet in request against the flows installed in the switch.

    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
    """
    match = do_match(flow_to_install, version, stored_flow_dict)
    return match


1		"""Switch match."""
2
3	1	import ipaddress
4
5	1	from pyof.v0x01.common.flow_match import FlowWildCards
6
7	1	IPV4_ETH_TYPE = 2048
8
9
10	1	def format_request(request):
11		"""Format user request to match function format."""
12		args = {}
13		for key, value in request.items():
14		args[key] = value
15		return args
16
17
18	1	def do_match(flow_to_install, version, stored_flow_dict):
19		"""Match a packet against this flow."""
20		if version == 0x01:
21		return match10(stored_flow_dict, flow_to_install)
22		elif version == 0x04:
23		return match13_no_strict(flow_to_install, stored_flow_dict)
24		raise NotImplementedError(f'Unsupported OpenFlow version {version}')
25
26
27	1	def _get_match_fields(flow_dict):
28		"""Generate match fields."""
29		match_fields = {}
30		if 'match' in flow_dict:
31		for key, value in flow_dict['match'].items():
32		match_fields[key] = value
33		return match_fields
34
35
36		# pylint: disable=too-many-return-statements, too-many-statements, R0912
37	1	def _match_ipv4(match_fields, args, wildcards):
38		"""Match IPV4."""
39		if not match_fields['eth_type'] == IPV4_ETH_TYPE:
40		return False
41		flow_ip_int = int(ipaddress.IPv4Address(match_fields.get('ipv4_src')))
42		if flow_ip_int != 0:
43		mask = (wildcards
44		& FlowWildCards.OFPFW_NW_SRC_MASK) >> \
45		FlowWildCards.OFPFW_NW_SRC_SHIFT
46		if mask > 32:
47		mask = 32
48		if mask != 32 and 'ipv4_src' not in args:
49		return False
50		mask = (0xffffffff << mask) & 0xffffffff
51		ip_int = int(ipaddress.IPv4Address(args.get('ipv4_src')))
52		if ip_int & mask != flow_ip_int & mask:
53		return False
54
55		flow_ip_int = int(ipaddress.IPv4Address(match_fields['ipv4_dst']))
56		if flow_ip_int != 0:
57		mask = (wildcards
58		& FlowWildCards.OFPFW_NW_DST_MASK) >> \
59		FlowWildCards.OFPFW_NW_DST_SHIFT
60		if mask > 32:
61		mask = 32
62		if mask != 32 and 'ipv4_dst' not in args:
63		return False
64		mask = (0xffffffff << mask) & 0xffffffff
65		ip_int = int(ipaddress.IPv4Address(args.get('ipv4_dst')))
66		if ip_int & mask != flow_ip_int & mask:
67		return False
68		if not wildcards & FlowWildCards.OFPFW_NW_TOS:
69		if 'ip_tos' not in args:
70		return False
71		if match_fields.get('ip_tos') != int(args.get('ip_tos')):
72		return False
73		if not wildcards & FlowWildCards.OFPFW_NW_PROTO:
74		if 'ip_proto' not in args:
75		return False
76		if match_fields.get('ip_proto') != int(args.get('ip_proto')):
77		return False
78		if not wildcards & FlowWildCards.OFPFW_TP_SRC:
79		if 'tp_src' not in args:
80		return False
81		if match_fields.get('tcp_src') != int(args.get('tp_src')):
82		return False
83		if not wildcards & FlowWildCards.OFPFW_TP_DST:
84		if 'tp_dst' not in args:
85		return False
86		if match_fields.get('tcp_dst') != int(args.get('tp_dst')):
87		return False
88		return True
89
90
91		# pylint: disable=too-many-return-statements, too-many-statements, R0912
92	1	def match10(flow_dict, args):
93		"""Match a packet against this flow (OF1.0)."""
94		match_fields = _get_match_fields(flow_dict)
95		wildcards = match_fields.get('wildcards')
96		if not wildcards & FlowWildCards.OFPFW_IN_PORT:
97		if 'in_port' not in args:
98		return False
99		if match_fields.get('in_port') != int(args.get('in_port')):
100		return False
101		if not wildcards & FlowWildCards.OFPFW_DL_VLAN_PCP:
102		if 'vlan_pcp' not in args:
103		return False
104		if match_fields.get('vlan_pcp') != int(args.get('vlan_pcp')):
105		return False
106		if not wildcards & FlowWildCards.OFPFW_DL_VLAN:
107		if 'vlan_vid' not in args:
108		return False
109		if match_fields.get('vlan_vid') != args.get('vlan_vid')[-1]:
110		return False
111		if not wildcards & FlowWildCards.OFPFW_DL_SRC:
112		if 'eth_src' not in args:
113		return False
114		if match_fields.get('eth_src') != args.get('eth_src'):
115		return False
116		if not wildcards & FlowWildCards.OFPFW_DL_DST:
117		if 'eth_dst' not in args:
118		return False
119		if match_fields.get('eth_dst') != args.get('eth_dst'):
120		return False
121		if not wildcards & FlowWildCards.OFPFW_DL_TYPE:
122		if 'eth_type' not in args:
123		return False
124		if match_fields.get('eth_type') != int(args.get('eth_type')):
125		return False
126		if not _match_ipv4(match_fields, args, wildcards):
127		return False
128		return flow_dict
129
130		# def match13(self, args):
131		# """Match a packet against this flow (OF1.3)."""
132		# for name in self.match:
133		# if name not in args:
134		# return False
135		# if name == 'vlan_vid':
136		# field = args[name][-1]
137		# else:
138		# field = args[name]
139		# if name not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
140		# if self.match[name].value != field:
141		# return False
142		# else:
143		# packet_ip = int(ipaddress.ip_address(field))
144		# ip_addr = self.match[name].value
145		# if packet_ip & ip_addr.netmask != ip_addr.address:
146		# return False
147		# return self
148
149
150	1	def match13_no_strict(flow_to_install, stored_flow_dict):
151		"""Match a packet againts the stored flow (OF 1.3).
152
153		Return the flow if any fields match, otherwise, return False.
154		"""
155		if flow_to_install.get('cookie_mask') and 'cookie' in stored_flow_dict:
156		cookie = flow_to_install['cookie_mask'] & flow_to_install['cookie']
157		if cookie == stored_flow_dict['cookie']:
158		return stored_flow_dict
159		return False
160
161		if 'match' not in flow_to_install:
162		return False
163
164		for key, value in flow_to_install.get('match').items():
165		if 'match' not in stored_flow_dict:
166		return False
167		if key not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
168		if value == stored_flow_dict['match'].get(key):
169		return stored_flow_dict
170		else:
171		field = flow_to_install.get(key)
172		packet_ip = int(ipaddress.ip_address(field))
173		ip_addr = value
174		if packet_ip & ip_addr.netmask == ip_addr.address:
175		return stored_flow_dict
176
177		return False
178
179
180	1	def match_flows(flow_to_install, version, stored_flow_dict):
181		# pylint: disable=bad-staticmethod-argument
182		"""
183		Match the packet in request against the flows installed in the switch.
184
185		Try the match with each flow, in other. If many is True, tries the
186		match with all flows, if False, tries until the first match.
187		:param args: packet data
188		:param many: Boolean, indicating whether to continue after matching the
189		first flow or not
190		:return: If many, the list of matched flows, or the matched flow
191		"""
192		match = do_match(flow_to_install, version, stored_flow_dict)
193		return match
194

kytos / flow_manager

Pull Request — master (#117)

build.match.match_flows() A

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