Total Complexity | 40 |
Total Lines | 282 |
Duplicated Lines | 45.39 % |
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 | from struct import pack |
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11 | from struct import unpack |
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12 | |||
13 | from exabgp.protocol.ip import IPv4 |
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14 | from exabgp.protocol.ip import IPv6 |
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15 | from exabgp.bgp.message.open.asn import ASN |
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16 | from exabgp.bgp.message.open.capability.asn4 import ASN4 |
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17 | from exabgp.bgp.message.update.attribute.community.extended import ExtendedCommunity |
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18 | from exabgp.bgp.message.update.attribute.community.extended import ExtendedCommunityIPv6 |
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19 | |||
20 | |||
21 | # ================================================================== TrafficRate |
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22 | # RFC 5575 |
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23 | |||
24 | View Code Duplication | @ExtendedCommunity.register |
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25 | class TrafficRate (ExtendedCommunity): |
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26 | COMMUNITY_TYPE = 0x80 |
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27 | COMMUNITY_SUBTYPE = 0x06 |
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28 | |||
29 | __slots__ = ['asn','rate'] |
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30 | |||
31 | def __init__ (self, asn, rate, community=None): |
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32 | self.asn = asn |
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33 | self.rate = rate |
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34 | ExtendedCommunity.__init__( |
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35 | self, |
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36 | community if community is not None else pack( |
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37 | "!2sHf", |
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38 | self._subtype(), |
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39 | asn,rate |
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40 | ) |
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41 | ) |
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42 | |||
43 | def __repr__ (self): |
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44 | return "rate-limit:%d" % self.rate |
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45 | |||
46 | @staticmethod |
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47 | def unpack (data): |
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48 | asn,rate = unpack('!Hf',data[2:8]) |
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49 | return TrafficRate(ASN(asn),rate,data[:8]) |
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50 | |||
51 | |||
52 | # ================================================================ TrafficAction |
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53 | # RFC 5575 |
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54 | |||
55 | @ExtendedCommunity.register |
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56 | class TrafficAction (ExtendedCommunity): |
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57 | COMMUNITY_TYPE = 0x80 |
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58 | COMMUNITY_SUBTYPE = 0x07 |
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59 | |||
60 | _sample = { |
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61 | False: 0x0, |
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62 | True: 0x2, |
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63 | } |
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64 | |||
65 | _terminal = { |
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66 | False: 0x0, |
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67 | True: 0x1, |
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68 | } |
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69 | |||
70 | __slots__ = ['sample','terminal'] |
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71 | |||
72 | def __init__ (self, sample, terminal, community=None): |
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73 | self.sample = sample |
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74 | self.terminal = terminal |
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75 | bitmask = self._sample[sample] | self._terminal[terminal] |
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76 | ExtendedCommunity.__init__( |
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77 | self, |
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78 | community if community is not None else pack( |
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79 | '!2sLBB', |
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80 | self._subtype(), |
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81 | 0,0,bitmask |
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82 | ) |
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83 | ) |
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84 | |||
85 | def __repr__ (self): |
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86 | s = [] |
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87 | if self.sample: |
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88 | s.append('sample') |
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89 | if self.terminal: |
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90 | s.append('terminal') |
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91 | return 'action %s' % '-'.join(s) |
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92 | |||
93 | @staticmethod |
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94 | def unpack (data): |
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95 | bit, = unpack('!B',data[7:8]) |
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96 | sample = bool(bit & 0x02) |
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97 | terminal = bool(bit & 0x01) |
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98 | return TrafficAction(sample,terminal,data[:8]) |
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99 | |||
100 | |||
101 | # ============================================================== TrafficRedirect |
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102 | # RFC 5575 and 7674 |
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103 | |||
104 | View Code Duplication | @ExtendedCommunity.register |
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105 | class TrafficRedirect (ExtendedCommunity): |
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106 | COMMUNITY_TYPE = 0x80 |
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107 | COMMUNITY_SUBTYPE = 0x08 |
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108 | |||
109 | __slots__ = ['asn','target'] |
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110 | |||
111 | def __init__ (self, asn, target, community=None): |
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112 | self.asn = asn |
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113 | self.target = target |
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114 | ExtendedCommunity.__init__( |
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115 | self, |
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116 | community if community is not None else pack( |
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117 | "!2sHL", |
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118 | self._subtype(), |
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119 | asn,target |
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120 | ) |
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121 | ) |
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122 | |||
123 | def __repr__ (self): |
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124 | return "redirect:%s:%s" % (self.asn,self.target) |
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125 | |||
126 | @staticmethod |
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127 | def unpack (data): |
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128 | asn,target = unpack('!HL',data[2:8]) |
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129 | return TrafficRedirect(ASN(asn),target,data[:8]) |
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130 | |||
131 | |||
132 | View Code Duplication | @ExtendedCommunity.register |
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133 | class TrafficRedirectASN4 (ExtendedCommunity): |
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134 | COMMUNITY_TYPE = 0x82 |
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135 | COMMUNITY_SUBTYPE = 0x08 |
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136 | |||
137 | __slots__ = ['asn', 'target'] |
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138 | |||
139 | def __init__(self, asn, target, community=None): |
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140 | self.asn = asn |
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141 | self.target = target |
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142 | ExtendedCommunity.__init__( |
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143 | self, |
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144 | community if community is not None else pack( |
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145 | "!2sLH", |
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146 | self._subtype(), |
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147 | asn, target |
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148 | ) |
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149 | ) |
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150 | |||
151 | def __str__(self): |
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152 | return "redirect:%s:%s" % (self.asn, self.target) |
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153 | |||
154 | @staticmethod |
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155 | def unpack(data): |
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156 | asn, target = unpack('!LH', data[2:8]) |
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157 | return TrafficRedirectASN4(ASN4(asn), target, data[:8]) |
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158 | |||
159 | # ================================================================== TrafficMark |
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160 | # RFC 5575 |
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161 | |||
162 | View Code Duplication | @ExtendedCommunity.register |
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163 | class TrafficMark (ExtendedCommunity): |
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164 | COMMUNITY_TYPE = 0x80 |
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165 | COMMUNITY_SUBTYPE = 0x09 |
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166 | |||
167 | __slots__ = ['dscp'] |
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168 | |||
169 | def __init__ (self, dscp, community=None): |
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170 | self.dscp = dscp |
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171 | ExtendedCommunity.__init__( |
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172 | self, |
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173 | community if community is not None else pack( |
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174 | "!2sLBB", |
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175 | self._subtype(), |
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176 | 0,0,dscp |
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177 | ) |
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178 | ) |
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179 | |||
180 | def __repr__ (self): |
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181 | return "mark %d" % self.dscp |
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182 | |||
183 | @staticmethod |
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184 | def unpack (data): |
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185 | dscp, = unpack('!B',data[7:8]) |
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186 | return TrafficMark(dscp,data[:8]) |
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187 | |||
188 | # =============================================================== TrafficNextHopIPv4IETF |
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189 | # draft-ietf-idr-flowspec-redirect-02 |
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190 | # see RFC 4360 for ipv4 address specific extended community format |
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191 | |||
192 | @ExtendedCommunity.register |
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193 | class TrafficNextHopIPv4IETF (ExtendedCommunity): |
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194 | COMMUNITY_TYPE = 0x01 |
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195 | COMMUNITY_SUBTYPE = 0x0C |
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196 | |||
197 | __slots__ = ['ip', 'copy'] |
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198 | |||
199 | def __init__ (self, ip, copy, community=None): |
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200 | self.ip = ip |
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201 | self.copy = copy |
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202 | ExtendedCommunity.__init__( |
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203 | self, |
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204 | community if community is not None else pack( |
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205 | "!2s4sH", |
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206 | self._subtype(), |
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207 | ip.pack(), |
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208 | 1 if copy else 0 |
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209 | ) |
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210 | ) |
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211 | |||
212 | def __repr__ (self): |
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213 | return "copy-to-nexthop-ietf" if self.copy else "redirect-to-nexthop-ietf" |
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214 | |||
215 | @staticmethod |
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216 | def unpack (data): |
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217 | ip, bit = unpack('!4sH', data[2:8]) |
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218 | return TrafficNextHopIPv4IETF(IPv4.ntop(ip), bool(bit & 0x01), data[:8]) |
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219 | |||
220 | # =============================================================== TrafficNextHopIPv6IETF |
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221 | # draft-ietf-idr-flowspec-redirect-02 |
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222 | # see RFC 5701 for ipv6 address specific extended community format |
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223 | |||
224 | @ExtendedCommunity.register |
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225 | class TrafficNextHopIPv6IETF (ExtendedCommunityIPv6): |
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226 | COMMUNITY_TYPE = 0x00 |
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227 | COMMUNITY_SUBTYPE = 0x0C |
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228 | |||
229 | __slots__ = ['ip', 'copy'] |
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230 | |||
231 | def __init__ (self, ip, copy, community=None): |
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232 | self.ip = ip |
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233 | self.copy = copy |
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234 | ExtendedCommunityIPv6.__init__( |
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235 | self, |
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236 | community if community is not None else pack( |
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237 | "!2s16sH", |
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238 | self._subtype(), |
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239 | ip.pack(), |
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240 | 1 if copy else 0 |
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241 | ) |
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242 | ) |
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243 | |||
244 | def __repr__ (self): |
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245 | return "copy-to-nexthop-ietf" if self.copy else "redirect-to-nexthop-ietf" |
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246 | |||
247 | @staticmethod |
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248 | def unpack (data): |
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249 | ip, bit = unpack('!16sH', data[2:20]) |
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250 | return TrafficNextHopIPv6IETF(IPv6.ntop(ip), bool(bit & 0x01), data[:20]) |
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251 | |||
252 | # =============================================================== TrafficNextHopSimpson |
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253 | # draft-simpson-idr-flowspec-redirect-02 |
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254 | |||
255 | # XXX: FIXME: I guess this should be a subclass of NextHop or IP .. |
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256 | |||
257 | View Code Duplication | @ExtendedCommunity.register |
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258 | class TrafficNextHopSimpson (ExtendedCommunity): |
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259 | COMMUNITY_TYPE = 0x08 |
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260 | COMMUNITY_SUBTYPE = 0x00 |
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261 | |||
262 | __slots__ = ['copy'] |
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263 | |||
264 | def __init__ (self, copy, community=None): |
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265 | self.copy = copy |
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266 | ExtendedCommunity.__init__( |
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267 | self, |
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268 | community if community is not None else pack( |
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269 | "!2sLH", |
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270 | self._subtype(), |
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271 | 0,1 if copy else 0 |
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272 | ) |
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273 | ) |
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274 | |||
275 | def __repr__ (self): |
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276 | return "copy-to-nexthop" if self.copy else "redirect-to-nexthop" |
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277 | |||
278 | @staticmethod |
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279 | def unpack (data): |
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280 | bit, = unpack('!B',data[7:8]) |
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281 | return TrafficNextHopSimpson(bool(bit & 0x01), data[:8]) |
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282 | |||
309 |