def _factory(self, data):
if not data:
return self
# We do not care if the attribute are transitive or not as we do not redistribute
flag = Flag(ord(data[0]))
code = AID(ord(data[1]))
if flag & Flag.EXTENDED_LENGTH:
length = unpack('!H', data[2:4])[0]
offset = 4
else:
length = ord(data[2])
offset = 3
if self.hasmp:
if code not in (AID.MP_REACH_NLRI, AID.MP_UNREACH_NLRI):
self.cacheable = False
self.prefix = ''
else:
self.prefix += data[:offset + length]
data = data[offset:]
next = data[length:]
attribute = data[:length]
logger = Logger()
logger.parser(
LazyFormat(
"parsing flag %x type %02x (%s) len %02x %s" %
(flag, int(code), code, length, 'payload ' if length else ''),
od, data[:length]))
if code == AID.ORIGIN and flag.matches(Origin.FLAG):
# This if block should never be called anymore ...
if not self.add_from_cache(code, attribute):
self.add(Origin(ord(attribute)), attribute)
return self.factory(next)
# only 2-4% of duplicated data - is it worth to cache ?
if code == AID.AS_PATH and flag.matches(ASPath.FLAG):
if length:
# we store the AS4_PATH as AS_PATH, do not over-write
if not self.has(code):
if not self.add_from_cache(code, attribute):
self.add(self.__new_ASPath(attribute), attribute)
return self.factory(next)
if code == AID.AS4_PATH and flag.matches(AS4Path.FLAG):
if length:
# ignore the AS4_PATH on new spekers as required by RFC 4893 section 4.1
if not self.negotiated.asn4:
# This replace the old AS_PATH
if not self.add_from_cache(code, attribute):
self.add(self.__new_ASPath4(attribute), attribute)
return self.factory(next)
if code == AID.NEXT_HOP and flag.matches(NextHop.FLAG):
# XXX: FIXME: we are double caching the NH (once in the class, once here)
if not self.add_from_cache(code, attribute):
self.add(cachedNextHop(attribute), attribute)
return self.factory(next)
if code == AID.MED and flag.matches(MED.FLAG):
if not self.add_from_cache(code, attribute):
self.add(MED(attribute), attribute)
return self.factory(next)
if code == AID.LOCAL_PREF and flag.matches(LocalPreference.FLAG):
if not self.add_from_cache(code, attribute):
self.add(LocalPreference(attribute), attribute)
return self.factory(next)
if code == AID.ATOMIC_AGGREGATE and flag.matches(AtomicAggregate.FLAG):
if not self.add_from_cache(code, attribute):
raise Notify(
3, 2, 'invalid ATOMIC_AGGREGATE %s' %
[hex(ord(_)) for _ in attribute])
return self.factory(next)
if code == AID.AGGREGATOR and flag.matches(Aggregator.FLAG):
# AS4_AGGREGATOR are stored as AGGREGATOR - so do not overwrite if exists
if not self.has(code):
if not self.add_from_cache(AID.AGGREGATOR, attribute):
self.add(Aggregator(attribute), attribute)
return self.factory(next)
if code == AID.AS4_AGGREGATOR and flag.matches(Aggregator.FLAG):
if not self.add_from_cache(AID.AGGREGATOR, attribute):
self.add(Aggregator(attribute), attribute)
return self.factory(next)
if code == AID.COMMUNITY and flag.matches(Communities.FLAG):
if not self.add_from_cache(code, attribute):
self.add(self.__new_communities(attribute), attribute)
return self.factory(next)
if code == AID.ORIGINATOR_ID and flag.matches(OriginatorID.FLAG):
if not self.add_from_cache(code, attribute):
self.add(OriginatorID(AFI.ipv4, SAFI.unicast, data[:4]),
attribute)
return self.factory(next)
if code == AID.CLUSTER_LIST and flag.matches(ClusterList.FLAG):
if not self.add_from_cache(code, attribute):
self.add(ClusterList(attribute), attribute)
return self.factory(next)
if code == AID.EXTENDED_COMMUNITY and flag.matches(ECommunities.FLAG):
if not self.add_from_cache(code, attribute):
self.add(self.__new_extended_communities(attribute), attribute)
return self.factory(next)
if code == AID.AIGP and flag.matches(AIGP.FLAG):
if self.negotiated.neighbor.aigp:
if not self.add_from_cache(code, attribute):
self.add(AIGP(attribute), attribute)
return self.factory(next)
if code == AID.MP_UNREACH_NLRI and flag.matches(MPURNLRI.FLAG):
self.hasmp = True
# -- Reading AFI/SAFI
data = data[:length]
afi, safi = unpack('!HB', data[:3])
offset = 3
data = data[offset:]
if (afi, safi) not in self.negotiated.families:
raise Notify(
3, 0,
'presented a non-negotiated family %d/%d' % (afi, safi))
# Is the peer going to send us some Path Information with the route (AddPath)
addpath = self.negotiated.addpath.receive(afi, safi)
# XXX: we do assume that it is an EOR. most likely harmless
if not data:
self.mp_withdraw.append(NLRIEOR(afi, safi, IN.announced))
return self.factory(next)
while data:
length, nlri = self.nlriFactory(afi, safi, data, addpath, None,
IN.withdrawn)
self.mp_withdraw.append(nlri)
data = data[length:]
logger.parser(
LazyFormat("parsed withdraw mp nlri %s payload " % nlri,
od, data[:length]))
return self.factory(next)
if code == AID.MP_REACH_NLRI and flag.matches(MPRNLRI.FLAG):
self.hasmp = True
data = data[:length]
# -- Reading AFI/SAFI
afi, safi = unpack('!HB', data[:3])
offset = 3
# we do not want to accept unknown families
if (afi, safi) not in self.negotiated.families:
raise Notify(
3, 0,
'presented a non-negotiated family %d/%d' % (afi, safi))
# -- Reading length of next-hop
len_nh = ord(data[offset])
offset += 1
rd = 0
# check next-hope size
if afi == AFI.ipv4:
if safi in (SAFI.unicast, SAFI.multicast):
if len_nh != 4:
raise Notify(
3, 0,
'invalid ipv4 unicast/multicast next-hop length %d expected 4'
% len_nh)
elif safi in (SAFI.mpls_vpn, ):
if len_nh != 12:
raise Notify(
3, 0,
'invalid ipv4 mpls_vpn next-hop length %d expected 12'
% len_nh)
rd = 8
elif safi in (SAFI.flow_ip, ):
if len_nh not in (0, 4):
raise Notify(
3, 0,
'invalid ipv4 flow_ip next-hop length %d expected 4'
% len_nh)
elif safi in (SAFI.flow_vpn, ):
if len_nh not in (0, 4):
raise Notify(
3, 0,
'invalid ipv4 flow_vpn next-hop length %d expected 4'
% len_nh)
elif afi == AFI.ipv6:
if safi in (SAFI.unicast, ):
if len_nh not in (16, 32):
raise Notify(
3, 0,
'invalid ipv6 unicast next-hop length %d expected 16 or 32'
% len_nh)
elif safi in (SAFI.mpls_vpn, ):
if len_nh not in (24, 40):
raise Notify(
3, 0,
'invalid ipv6 mpls_vpn next-hop length %d expected 24 or 40'
% len_nh)
rd = 8
elif safi in (SAFI.flow_ip, ):
if len_nh not in (0, 16, 32):
raise Notify(
3, 0,
'invalid ipv6 flow_ip next-hop length %d expected 0, 16 or 32'
% len_nh)
elif safi in (SAFI.flow_vpn, ):
if len_nh not in (0, 16, 32):
raise Notify(
3, 0,
'invalid ipv6 flow_vpn next-hop length %d expected 0, 16 or 32'
% len_nh)
size = len_nh - rd
# XXX: FIXME: GET IT FROM CACHE HERE ?
nh = data[offset + rd:offset + rd + size]
# chech the RD is well zero
if rd and sum([int(ord(_)) for _ in data[offset:8]]) != 0:
raise Notify(
3, 0,
"MP_REACH_NLRI next-hop's route-distinguisher must be zero"
)
offset += len_nh
# Skip a reserved bit as somone had to bug us !
reserved = ord(data[offset])
offset += 1
if reserved != 0:
raise Notify(3, 0,
'the reserved bit of MP_REACH_NLRI is not zero')
# Is the peer going to send us some Path Information with the route (AddPath)
addpath = self.negotiated.addpath.receive(afi, safi)
# Reading the NLRIs
data = data[offset:]
while data:
length, nlri = self.nlriFactory(afi, safi, data, addpath, nh,
IN.announced)
self.mp_announce.append(nlri)
logger.parser(
LazyFormat("parsed announce mp nlri %s payload " % nlri,
od, data[:length]))
data = data[length:]
return self.factory(next)
if flag & Flag.TRANSITIVE:
if code in self.known_attributes:
# XXX: FIXME: we should really close the session
logger.parser(
'ignoring implemented invalid transitive attribute (code 0x%02X, flag 0x%02X)'
% (code, flag))
return self.factory(next)
if not self.add_from_cache(code, attribute):
self.add(UnknownAttribute(code, flag, attribute), attribute)
return self.factory(next)
logger.parser(
'ignoring non-transitive attribute (code 0x%02X, flag 0x%02X)' %
(code, flag))
return self.factory(next)
def originator_id(tokeniser):
value = tokeniser()
if not value.isdigit():
raise ValueError('invalid Originator ID %s' % value)
return OriginatorID(value)