Total Complexity | 44 |
Total Lines | 306 |
Duplicated Lines | 42.81 % |
Changes | 0 |
Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like exabgp.bgp.message.update.attribute.community.extended.traffic often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
1 | # encoding: utf-8 |
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2 | """ |
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3 | traffic.py |
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4 | |||
5 | Created by Thomas Mangin on 2014-06-21. |
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6 | Copyright (c) 2014-2017 Exa Networks. All rights reserved. |
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7 | License: 3-clause BSD. (See the COPYRIGHT file) |
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8 | """ |
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9 | |||
10 | import socket |
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11 | |||
12 | from struct import pack |
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13 | from struct import unpack |
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14 | |||
15 | from exabgp.protocol.ip import IPv4 |
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16 | from exabgp.protocol.ip import IPv6 |
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17 | from exabgp.bgp.message.open.asn import ASN |
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18 | from exabgp.bgp.message.open.capability.asn4 import ASN4 |
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19 | from exabgp.bgp.message.update.attribute.community.extended import ExtendedCommunity |
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20 | from exabgp.bgp.message.update.attribute.community.extended import ExtendedCommunityIPv6 |
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21 | |||
22 | |||
23 | # ================================================================== TrafficRate |
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24 | # RFC 5575 |
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25 | |||
26 | View Code Duplication | @ExtendedCommunity.register |
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27 | class TrafficRate (ExtendedCommunity): |
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28 | COMMUNITY_TYPE = 0x80 |
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29 | COMMUNITY_SUBTYPE = 0x06 |
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30 | |||
31 | __slots__ = ['asn','rate'] |
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32 | |||
33 | def __init__ (self, asn, rate, community=None): |
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34 | self.asn = asn |
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35 | self.rate = rate |
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36 | ExtendedCommunity.__init__( |
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37 | self, |
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38 | community if community is not None else pack( |
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39 | "!2sHf", |
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40 | self._subtype(), |
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41 | asn,rate |
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42 | ) |
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43 | ) |
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44 | |||
45 | def __repr__ (self): |
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46 | return "rate-limit:%d" % self.rate |
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47 | |||
48 | @staticmethod |
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49 | def unpack (data): |
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50 | asn,rate = unpack('!Hf',data[2:8]) |
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51 | return TrafficRate(ASN(asn),rate,data[:8]) |
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52 | |||
53 | |||
54 | # ================================================================ TrafficAction |
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55 | # RFC 5575 |
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56 | |||
57 | @ExtendedCommunity.register |
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58 | class TrafficAction (ExtendedCommunity): |
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59 | COMMUNITY_TYPE = 0x80 |
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60 | COMMUNITY_SUBTYPE = 0x07 |
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61 | |||
62 | _sample = { |
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63 | False: 0x0, |
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64 | True: 0x2, |
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65 | } |
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66 | |||
67 | _terminal = { |
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68 | False: 0x0, |
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69 | True: 0x1, |
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70 | } |
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71 | |||
72 | __slots__ = ['sample','terminal'] |
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73 | |||
74 | def __init__ (self, sample, terminal, community=None): |
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75 | self.sample = sample |
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76 | self.terminal = terminal |
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77 | bitmask = self._sample[sample] | self._terminal[terminal] |
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78 | ExtendedCommunity.__init__( |
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79 | self, |
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80 | community if community is not None else pack( |
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81 | '!2sLBB', |
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82 | self._subtype(), |
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83 | 0,0,bitmask |
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84 | ) |
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85 | ) |
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86 | |||
87 | def __repr__ (self): |
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88 | s = [] |
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89 | if self.sample: |
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90 | s.append('sample') |
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91 | if self.terminal: |
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92 | s.append('terminal') |
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93 | return 'action %s' % '-'.join(s) |
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94 | |||
95 | @staticmethod |
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96 | def unpack (data): |
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97 | bit, = unpack('!B',data[7:8]) |
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98 | sample = bool(bit & 0x02) |
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99 | terminal = bool(bit & 0x01) |
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100 | return TrafficAction(sample,terminal,data[:8]) |
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101 | |||
102 | |||
103 | # ============================================================== TrafficRedirect |
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104 | # RFC 5575 and 7674 |
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105 | |||
106 | View Code Duplication | @ExtendedCommunity.register |
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107 | class TrafficRedirect (ExtendedCommunity): |
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108 | COMMUNITY_TYPE = 0x80 |
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109 | COMMUNITY_SUBTYPE = 0x08 |
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110 | |||
111 | __slots__ = ['asn','target'] |
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112 | |||
113 | def __init__ (self, asn, target, community=None): |
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114 | self.asn = asn |
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115 | self.target = target |
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116 | ExtendedCommunity.__init__( |
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117 | self, |
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118 | community if community is not None else pack( |
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119 | "!2sHL", |
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120 | self._subtype(), |
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121 | asn,target |
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122 | ) |
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123 | ) |
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124 | |||
125 | def __repr__ (self): |
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126 | return "redirect:%s:%s" % (self.asn,self.target) |
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127 | |||
128 | @staticmethod |
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129 | def unpack (data): |
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130 | asn,target = unpack('!HL',data[2:8]) |
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131 | return TrafficRedirect(ASN(asn),target,data[:8]) |
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132 | |||
133 | |||
134 | @ExtendedCommunity.register |
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135 | class TrafficRedirectASN4 (ExtendedCommunity): |
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136 | COMMUNITY_TYPE = 0x82 |
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137 | COMMUNITY_SUBTYPE = 0x08 |
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138 | |||
139 | __slots__ = ['asn', 'target'] |
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140 | |||
141 | def __init__(self, asn, target, community=None): |
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142 | self.asn = asn |
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143 | self.target = target |
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144 | ExtendedCommunity.__init__( |
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145 | self, |
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146 | community if community is not None else pack( |
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147 | "!2sLH", |
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148 | self._subtype(), |
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149 | asn, target |
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150 | ) |
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151 | ) |
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152 | |||
153 | def __str__(self): |
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154 | return "redirect:%s:%s" % (self.asn, self.target) |
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155 | |||
156 | @staticmethod |
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157 | def unpack(data): |
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158 | asn, target = unpack('!LH', data[2:8]) |
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159 | return TrafficRedirectASN4(ASN4(asn), target, data[:8]) |
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160 | |||
161 | # ================================================================== TrafficMark |
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162 | # RFC 5575 |
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163 | |||
164 | @ExtendedCommunity.register |
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165 | class TrafficMark (ExtendedCommunity): |
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166 | COMMUNITY_TYPE = 0x80 |
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167 | COMMUNITY_SUBTYPE = 0x09 |
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168 | |||
169 | __slots__ = ['dscp'] |
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170 | |||
171 | def __init__ (self, dscp, community=None): |
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172 | self.dscp = dscp |
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173 | ExtendedCommunity.__init__( |
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174 | self, |
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175 | community if community is not None else pack( |
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176 | "!2sLBB", |
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177 | self._subtype(), |
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178 | 0,0,dscp |
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179 | ) |
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180 | ) |
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181 | |||
182 | def __repr__ (self): |
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183 | return "mark %d" % self.dscp |
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184 | |||
185 | @staticmethod |
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186 | def unpack (data): |
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187 | dscp, = unpack('!B',data[7:8]) |
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188 | return TrafficMark(dscp,data[:8]) |
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189 | |||
190 | # =============================================================== TrafficNextHopIPv4IETF |
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191 | # draft-ietf-idr-flowspec-redirect-02 |
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192 | # see RFC 4360 for ipv4 address specific extended community format |
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193 | |||
194 | View Code Duplication | @ExtendedCommunity.register |
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195 | class TrafficNextHopIPv4IETF (ExtendedCommunity): |
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196 | COMMUNITY_TYPE = 0x01 |
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197 | COMMUNITY_SUBTYPE = 0x0C |
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198 | |||
199 | __slots__ = ['ip', 'copy'] |
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200 | |||
201 | def __init__ (self, ip, copy, community=None): |
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202 | self.ip = ip |
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203 | self.copy = copy |
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204 | ExtendedCommunity.__init__( |
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205 | self, |
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206 | community if community is not None else pack( |
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207 | "!2s4sH", |
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208 | self._subtype(), |
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209 | ip.pack(), |
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210 | 1 if copy else 0 |
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211 | ) |
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212 | ) |
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213 | |||
214 | def __repr__ (self): |
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215 | return "copy-to-nexthop-ietf" if self.copy else "redirect-to-nexthop-ietf" |
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216 | |||
217 | @staticmethod |
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218 | def unpack (data): |
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219 | ip, bit = unpack('!4sH', data[2:8]) |
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220 | return TrafficNextHopIPv4IETF(IPv4.ntop(ip), bool(bit & 0x01), data[:8]) |
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221 | |||
222 | # =============================================================== TrafficNextHopIPv6IETF |
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223 | # draft-ietf-idr-flowspec-redirect-02 |
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224 | # see RFC 5701 for ipv6 address specific extended community format |
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225 | |||
226 | View Code Duplication | @ExtendedCommunityIPv6.register |
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227 | class TrafficNextHopIPv6IETF ( ExtendedCommunityIPv6): |
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228 | COMMUNITY_TYPE = 0x00 |
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229 | COMMUNITY_SUBTYPE = 0x0C |
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230 | |||
231 | __slots__ = ['ip', 'copy'] |
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232 | |||
233 | def __init__ (self, ip, copy, community=None): |
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234 | self.ip = ip |
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235 | self.copy = copy |
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236 | ExtendedCommunityIPv6.__init__( |
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237 | self, |
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238 | community if community is not None else pack( |
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239 | "!2s16sH", |
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240 | self._subtype(), |
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241 | ip.pack(), |
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242 | 1 if copy else 0 |
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243 | ) |
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244 | ) |
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245 | |||
246 | def __repr__ (self): |
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247 | return "copy-to-nexthop-ietf" if self.copy else "redirect-to-nexthop-ietf" |
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248 | |||
249 | @staticmethod |
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250 | def unpack (data): |
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251 | ip, bit = unpack('!16sH', data[2:20]) |
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252 | return TrafficNextHopIPv6IETF(IPv6.ntop(ip), bool(bit & 0x01), data[:20]) |
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253 | |||
254 | # =============================================================== TrafficNextHopSimpson |
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255 | # draft-simpson-idr-flowspec-redirect-02 |
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256 | |||
257 | # XXX: FIXME: I guess this should be a subclass of NextHop or IP .. |
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258 | |||
259 | View Code Duplication | @ExtendedCommunity.register |
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260 | class TrafficNextHopSimpson (ExtendedCommunity): |
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261 | COMMUNITY_TYPE = 0x08 |
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262 | COMMUNITY_SUBTYPE = 0x00 |
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263 | |||
264 | __slots__ = ['copy'] |
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265 | |||
266 | def __init__ (self, copy, community=None): |
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267 | self.copy = copy |
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268 | ExtendedCommunity.__init__( |
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269 | self, |
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270 | community if community is not None else pack( |
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271 | "!2sLH", |
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272 | self._subtype(), |
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273 | 0,1 if copy else 0 |
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274 | ) |
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275 | ) |
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276 | |||
277 | def __repr__ (self): |
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278 | return "copy-to-nexthop" if self.copy else "redirect-to-nexthop" |
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279 | |||
280 | @staticmethod |
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281 | def unpack (data): |
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282 | bit, = unpack('!B',data[7:8]) |
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283 | return TrafficNextHopSimpson(bool(bit & 0x01), data[:8]) |
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284 | |||
285 | # ============================================================ TrafficRedirectIPv6 |
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286 | # https://tools.ietf.org/html/rfc5701 |
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287 | |||
288 | @ExtendedCommunityIPv6.register |
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289 | class TrafficRedirectIPv6 (ExtendedCommunityIPv6): |
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290 | COMMUNITY_TYPE = 0x00 |
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291 | COMMUNITY_SUBTYPE = 0x02 |
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292 | |||
293 | def __init__(self, ip, asn, community=None): |
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294 | self.ip = ip |
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295 | self.asn = asn |
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296 | ExtendedCommunityIPv6.__init__(self, community if community is not None else pack( |
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297 | "!BB16sH", 0x00, 0x02, socket.inet_aton(socket.AF_INET6, ip), asn)) |
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298 | |||
299 | def __str__(self): |
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300 | return "redirect %s:%d" % (self.ip, self.asn) |
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301 | |||
302 | @staticmethod |
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303 | def unpack(data): |
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304 | ip, asn = unpack('!16sH', data[2:11]) |
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305 | return TrafficRedirectIPv6(socket.inet_ntoa(socket.AF_INET6, ip), asn, data[:11]) |
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306 | |||
333 |