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# encoding: utf-8 |
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""" |
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Copyright (c) 2016 Evelio Vila <[email protected]> |
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Copyright (c) 2009-2017 Exa Networks. All rights reserved. |
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License: 3-clause BSD. (See the COPYRIGHT file) |
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""" |
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import json |
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import binascii |
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import itertools |
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from struct import unpack |
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from exabgp.util import concat_strs |
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from exabgp.vendoring.bitstring import BitArray |
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from exabgp.bgp.message.notification import Notify |
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from exabgp.bgp.message.update.attribute.attribute import Attribute |
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@Attribute.register() |
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class LINKSTATE(Attribute): |
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ID = Attribute.CODE.BGP_LS |
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FLAG = Attribute.Flag.OPTIONAL |
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TLV = -1 |
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# Registered subclasses we know how to decode |
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registered_lsids = dict() |
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# what this implementation knows as LS attributes |
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node_lsids = [] |
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link_lsids = [] |
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prefix_lsids = [] |
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def __init__(self, ls_attrs): |
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self.ls_attrs = ls_attrs |
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@classmethod |
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def register(cls,lsid=None,flag=None): |
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def register_lsid (klass): |
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scode = klass.TLV if lsid is None else lsid |
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if scode in cls.registered_lsids: |
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raise RuntimeError('only one class can be registered per BGP link state attribute type') |
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cls.registered_lsids[scode] = klass |
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return klass |
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return register_lsid |
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@classmethod |
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def registered(cls, lsid, flag=None): |
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return lsid in cls.registered_lsids |
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@classmethod |
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def unpack(cls, data, negotiated): |
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ls_attrs = [] |
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while data: |
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scode, length = unpack('!HH',data[:4]) |
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if scode in cls.registered_lsids: |
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klass = cls.registered_lsids[scode].unpack(data[4:length+4],length) |
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else: |
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klass = GenericLSID(scode,data[4:length+4]) |
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klass.TLV = scode |
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ls_attrs.append(klass) |
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data = data[length+4:] |
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# Remove all but last instance of each TLV class - the last holds state for all TLVs of that type |
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ls_attrs = list({ls_attr.TLV: ls_attr for ls_attr in ls_attrs}.values()) |
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for klass in ls_attrs: |
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if hasattr(klass, 'terids') or hasattr(klass, 'sr_adj_sids') or hasattr(klass, 'sr_adj_lan_sids'): |
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klass.reset() |
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return cls(ls_attrs=ls_attrs) |
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def json (self,compact=None): |
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content = ', '.join(d.json() for d in self.ls_attrs) |
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return '{ %s }' % (content) |
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def __str__(self): |
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return ', '.join(str(d) for d in self.ls_attrs) |
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View Code Duplication |
class GenericLSID(object): |
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TLV = 99999 |
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def __init__ (self, code, rep): |
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self.rep = rep |
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self.code = code |
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def __repr__ (self): |
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return "Attribute with code [ %s ] not implemented" % (self.code) |
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@classmethod |
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def unpack (cls,scode,data): |
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length = len(data) |
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info = binascii.b2a_uu(data[:length]) |
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return cls(code=scode,rep=info) |
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def json (self,compact=None): |
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return '"attribute-not-implemented": "%s"' % (self.code) |
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class LsGenericFlags(object): |
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# draft-ietf-isis-segment-routing-extensions Prefix-SID Sub-TLV |
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ISIS_SR_FLAGS = ['R', 'N', 'P', 'E', 'V', 'L', 'RSV', 'RSV'] |
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# RFC 7794 IPv4/IPv6 Extended Reachability Attribute Flags |
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ISIS_SR_ATTR_FLAGS = ['X', 'R', 'N', 'RSV', 'RSV', 'RSV', 'RSV', 'RSV'] |
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# draft-ietf-isis-segment-routing-extensions - Adj-SID IS-IS Flags |
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ISIS_SR_ADJ_FLAGS = ['F', 'B', 'V', 'L', 'S', 'P', 'RSV', 'RSV'] |
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# isis-segment-routing-extensions 3.1. SR-Capabilities Sub-TLV |
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ISIS_SR_CAP_FLAGS = ['I', 'V', 'RSV', 'RSV', 'RSV', 'RSV', 'RSV', 'RSV'] |
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# RFC 7752 3.3.1.1. Node Flag Bits TLV |
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LS_NODE_FLAGS = ['O', 'T', 'E', 'B', 'R', 'V', 'RSV', 'RSV'] |
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# RFC 7752 3.3.3.1. IGP Flags TLV |
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LS_IGP_FLAGS = ['D', 'N', 'L', 'P', 'RSV', 'RSV', 'RSV', 'RSV'] |
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# RFC 7752 3.3.2.2. MPLS Protocol Mask TLV |
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LS_MPLS_MASK = ['LDP', 'RSVP-TE', 'RSV', 'RSV', 'RSV', 'RSV', 'RSV', 'RSV'] |
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# RFC 5307 1.2. |
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LS_PROTECTION_MASK = ['ExtraTrafic', 'Unprotected', 'Shared', 'Dedicated 1:1', |
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'Dedicated 1+1', 'Enhanced', 'RSV', 'RSV'] |
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def __init__(self,flags): |
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self.flags = flags |
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@classmethod |
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def unpack(cls,data,pattern): |
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pad = pattern.count('RSV') |
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repeat = len(pattern) - pad |
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flag_array = binascii.b2a_hex(data) |
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hex_rep = hex(int(flag_array, 16)) |
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bit_array = BitArray(hex_rep) |
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valid_flags = [concat_strs(''.join(item), ''.join(itertools.repeat('0',pad))) |
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for item in itertools.product('01', repeat=repeat)] |
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valid_flags.append('0000') |
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if bit_array.bin in valid_flags: |
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flags = dict(zip(pattern, [0, ] * len(pattern))) |
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flags.update(dict((k, int(v)) for k, v in zip(pattern, bit_array.bin))) |
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else: |
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raise Notify(3,5, "Invalid SR flags mask") |
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return cls(flags=flags) |
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def json (self,compact=None): |
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return json.dumps(self.flags) |
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def __repr__ (self): |
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return str(self.flags) |
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Exa-Networks /
exabgp
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