build.match._match_ipv4_10() - Code Metrics - Inspection of "Add support for non-strict exclusion in the consis..." - kytos/flow_manager - Measure and Improve Code Quality continuously with Scrutinizer

Test Failed

Pull Request — master (#117)

by Carlos

created 2021-04-13 12:52 UTC

build.match._match_ipv4_10() F

↳ Parent: build.match

Complexity

Conditions

Size

Total Lines	51
Code Lines	50

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	24
eloc	50
nop	3
dl	0
loc	51
rs	0
c	0
b	0
f	0

How to fix Long Method Complexity

"""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_10(match_fields, args, wildcards):
    """Match IPV4 fields against packet with Flow (OF1.0)."""
    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_10(match_fields, args, wildcards):
        return False
    return flow_dict


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'] & flow_to_install['cookie_mask']
        stored_cookie = stored_flow_dict['cookie'] & flow_to_install['cookie_mask']
        if cookie == stored_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 = stored_flow_dict['match'].get(key)
            if not field:
                return False
            masked_ip_addr = ipaddress.ip_network(value, False)
            field_mask = field + "/" + str(masked_ip_addr.netmask)
            masked_stored_ip = ipaddress.ip_network(field_mask, False)
            if masked_ip_addr == masked_stored_ip:
                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			import ipaddress
4
5			from pyof.v0x01.common.flow_match import FlowWildCards
6
7			IPV4_ETH_TYPE = 2048
8
9
10			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			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			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			def _match_ipv4_10(match_fields, args, wildcards):
38			"""Match IPV4 fields against packet with Flow (OF1.0)."""
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			flow_ip_int = int(ipaddress.IPv4Address(match_fields['ipv4_dst']))
55			if flow_ip_int != 0:
56			mask = (wildcards
57			& FlowWildCards.OFPFW_NW_DST_MASK) >> \
58			FlowWildCards.OFPFW_NW_DST_SHIFT
59			if mask > 32:
60			mask = 32
61			if mask != 32 and 'ipv4_dst' not in args:
62			return False
63			mask = (0xffffffff << mask) & 0xffffffff
64			ip_int = int(ipaddress.IPv4Address(args.get('ipv4_dst')))
65			if ip_int & mask != flow_ip_int & mask:
66			return False
67			if not wildcards & FlowWildCards.OFPFW_NW_TOS:
68			if 'ip_tos' not in args:
69			return False
70			if match_fields.get('ip_tos') != int(args.get('ip_tos')):
71			return False
72			if not wildcards & FlowWildCards.OFPFW_NW_PROTO:
73			if 'ip_proto' not in args:
74			return False
75			if match_fields.get('ip_proto') != int(args.get('ip_proto')):
76			return False
77			if not wildcards & FlowWildCards.OFPFW_TP_SRC:
78			if 'tp_src' not in args:
79			return False
80			if match_fields.get('tcp_src') != int(args.get('tp_src')):
81			return False
82			if not wildcards & FlowWildCards.OFPFW_TP_DST:
83			if 'tp_dst' not in args:
84			return False
85			if match_fields.get('tcp_dst') != int(args.get('tp_dst')):
86			return False
87			return True
88
89
90			# pylint: disable=too-many-return-statements, too-many-statements, R0912
91			def match10(flow_dict, args):
92			"""Match a packet against this flow (OF1.0)."""
93			match_fields = _get_match_fields(flow_dict)
94			wildcards = match_fields.get('wildcards')
95			if not wildcards & FlowWildCards.OFPFW_IN_PORT:
96			if 'in_port' not in args:
97			return False
98			if match_fields.get('in_port') != int(args.get('in_port')):
99			return False
100			if not wildcards & FlowWildCards.OFPFW_DL_VLAN_PCP:
101			if 'vlan_pcp' not in args:
102			return False
103			if match_fields.get('vlan_pcp') != int(args.get('vlan_pcp')):
104			return False
105			if not wildcards & FlowWildCards.OFPFW_DL_VLAN:
106			if 'vlan_vid' not in args:
107			return False
108			if match_fields.get('vlan_vid') != args.get('vlan_vid')[-1]:
109			return False
110			if not wildcards & FlowWildCards.OFPFW_DL_SRC:
111			if 'eth_src' not in args:
112			return False
113			if match_fields.get('eth_src') != args.get('eth_src'):
114			return False
115			if not wildcards & FlowWildCards.OFPFW_DL_DST:
116			if 'eth_dst' not in args:
117			return False
118			if match_fields.get('eth_dst') != args.get('eth_dst'):
119			return False
120			if not wildcards & FlowWildCards.OFPFW_DL_TYPE:
121			if 'eth_type' not in args:
122			return False
123			if match_fields.get('eth_type') != int(args.get('eth_type')):
124			return False
125			if not _match_ipv4_10(match_fields, args, wildcards):
126			return False
127			return flow_dict
128
129
130			def match13_no_strict(flow_to_install, stored_flow_dict):
131			"""Match a packet againts the stored flow (OF 1.3).
132
133			Return the flow if any fields match, otherwise, return False.
134			"""
135			if flow_to_install.get('cookie_mask') and 'cookie' in stored_flow_dict:
136			cookie = flow_to_install['cookie'] & flow_to_install['cookie_mask']
137			stored_cookie = stored_flow_dict['cookie'] & flow_to_install['cookie_mask']
138			if cookie == stored_cookie:
139			return stored_flow_dict
140			return False
141			if 'match' not in flow_to_install:
142			return False
143
144			for key, value in flow_to_install.get('match').items():
145			if 'match' not in stored_flow_dict:
146			return False
147			if key not in ('ipv4_src', 'ipv4_dst', 'ipv6_src', 'ipv6_dst'):
148			if value == stored_flow_dict['match'].get(key):
149			return stored_flow_dict
150			else:
151			field = stored_flow_dict['match'].get(key)
152			if not field:
153			return False
154			masked_ip_addr = ipaddress.ip_network(value, False)
155			field_mask = field + "/" + str(masked_ip_addr.netmask)
156			masked_stored_ip = ipaddress.ip_network(field_mask, False)
157			if masked_ip_addr == masked_stored_ip:
158			return stored_flow_dict
159			return False
160
161
162			def match_flows(flow_to_install, version, stored_flow_dict):
163			# pylint: disable=bad-staticmethod-argument
164			"""
165			Match the packet in request against the flows installed in the switch.
166
167			Try the match with each flow, in other. If many is True, tries the
168			match with all flows, if False, tries until the first match.
169			:param args: packet data
170			:param many: Boolean, indicating whether to continue after matching the
171			first flow or not
172			:return: If many, the list of matched flows, or the matched flow
173			"""
174			match = do_match(flow_to_install, version, stored_flow_dict)
175			return match
176

kytos / flow_manager

Pull Request — master (#117)

build.match._match_ipv4_10() F

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How to fix Long Method Complexity

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