def parse(cls, value):
try:
afi, safi, nexthop_length = struct.unpack('!HBB', value[0:4])
nexthop_bin = value[4:4 + nexthop_length]
nlri_bin = value[5 + nexthop_length:]
except Exception:
# error when lenght is wrong
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=repr(value))
# Address Family IPv4
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST:
nlri = IPv4MPLSVPN.parse(nlri_bin)
elif safi == safn.SAFNUM_FSPEC_RULE:
# if nlri length is greater than 240 bytes, it is encoded over 2 bytes
if len(nlri_bin) >= 240:
nlri_bin = nlri_bin[2:]
else:
nlri_bin = nlri_bin[1:]
nlri = IPv4FlowSpec.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop_bin, nlri=nlri)
else:
nlri = repr(nlri_bin)
# # Address Family IPv6
elif afi == afn.AFNUM_INET6:
# IPv6 unicast
if safi == safn.SAFNUM_UNICAST:
# decode nexthop
# RFC 2545
# The value of the Length of Next Hop Network Address field on a
# MP_REACH_NLRI attribute shall be set to 16, when only a global
# address is present, or 32 if a link-local address is also included in
# the Next Hop field.
#
# The link-local address shall be included in the Next Hop field if and
# only if the BGP speaker shares a common subnet with the entity
# identified by the global IPv6 address carried in the Network Address
# of Next Hop field and the peer the route is being advertised to.
nexthop_addrlen = 16
has_link_local = False
nexthop = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin[:nexthop_addrlen]), 16)))
if len(nexthop_bin) == 2 * nexthop_addrlen:
# has link local address
has_link_local = True
linklocal_nexthop = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin[nexthop_addrlen:]), 16)))
nlri = IPv6Unicast.parse(nlri_bin)
if has_link_local:
return dict(afi_safi=(afi, safi), nexthop=nexthop, linklocal_nexthop=linklocal_nexthop, nlri=nlri)
else:
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
else:
nlri = repr(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop_bin, nlri=nlri_bin)
def parse(cls, value):
try:
afi, safi = struct.unpack('!HB', value[0:3])
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data='')
nlri_bin = value[3:]
# for IPv4
if afi == afn.AFNUM_INET:
# VPNv4
if safi == safn.SAFNUM_LAB_VPNUNICAST:
nlri = IPv4MPLSVPN.parse(nlri_bin, iswithdraw=True)
return dict(afi_safi=(afi, safi), withdraw=nlri)
# BGP flow spec
elif safi == safn.SAFNUM_FSPEC_RULE:
# if nlri length is greater than 240 bytes, it is encoded over 2 bytes
withdraw_list = []
while nlri_bin:
length = ord(nlri_bin[0])
if length >> 4 == 0xf and len(nlri_bin) > 2:
length = struct.unpack('!H', nlri_bin[:2])[0]
nlri_tmp = nlri_bin[2:length + 2]
nlri_bin = nlri_bin[length + 2:]
else:
nlri_tmp = nlri_bin[1:length + 1]
nlri_bin = nlri_bin[length + 1:]
nlri = IPv4FlowSpec.parse(nlri_tmp)
if nlri:
withdraw_list.append(nlri)
return dict(afi_safi=(afi, safi), withdraw=withdraw_list)
else:
return dict(afi_safi=(afn.AFNUM_INET, safi),
withdraw=repr(nlri_bin))
# for ipv6
elif afi == afn.AFNUM_INET6:
# for ipv6 unicast
if safi == safn.SAFNUM_UNICAST:
return dict(afi_safi=(afi, safi),
withdraw=IPv6Unicast.parse(nlri_data=nlri_bin))
elif safi == safn.SAFNUM_LAB_VPNUNICAST:
return dict(afi_safi=(afi, safi),
withdraw=IPv6MPLSVPN.parse(value=nlri_bin,
iswithdraw=True))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
# for evpn
if safi == safn.SAFNUM_EVPN:
return dict(afi_safi=(afi, safi),
withdraw=EVPN.parse(nlri_data=nlri_bin))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
def parse(cls, value):
try:
afi, safi = struct.unpack('!HB', value[0:3])
except Exception:
raise excep.UpdateMessageError(sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data='')
nlri_bin = value[3:]
# for IPv4
if afi == afn.AFNUM_INET:
# BGP flow spec
if safi == safn.SAFNUM_FSPEC_RULE:
# if nlri length is greater than 240 bytes, it is encoded over 2 bytes
if len(nlri_bin) >= 240:
nlri_bin = nlri_bin[2:]
else:
nlri_bin = nlri_bin[1:]
return dict(afi_safi=(afi, safi), withdraw=IPv4FlowSpec().parse(value=nlri_bin))
else:
return dict(afi_safi=(afn.AFNUM_INET, safi), withdraw=repr(nlri_bin))
# for ipv6
elif afi == afn.AFNUM_INET6:
# for ipv6 unicast
if safi == safn.SAFNUM_UNICAST:
return dict(afi_safi=(afi, safi), withdraw=IPv6Unicast.parse(nlri_data=nlri_bin))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
def test_construct_nlri(self):
nlri_list = [
'::2001:db8:1:2/64', '::2001:db8:1:1/64', '::2001:db8:1:0/64'
]
value_hex = IPv6Unicast.construct(nlri_list)
value_hoped = b'\x40\x20\x01\x0d\xb8\x00\x01\x00\x02\x40\x20\x01\x0d\xb8\x00\x01\x00\x01\x40\x20\x01\x0d' \
b'\xb8\x00\x01\x00\x00'
self.assertEqual(value_hoped, value_hex)
def test_construct_nlri_2(self):
nlri_list = [
'2001:3232::1/128', '::2001:3232:1:0/64', '2001:4837:1632::2/127'
]
value_hex = IPv6Unicast.construct(nlri_list)
value_hoped = b'\x80\x20\x01\x32\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x40\x20\x01\x32' \
b'\x32\x00\x01\x00\x00\x7f\x20\x01\x48\x37\x16\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'
self.assertEqual(value_hoped, value_hex)
def test_parse_withdraw(self):
nlri_data = b'\x40\x20\x01\x0d\xb8\x00\x01\x00\x02\x40\x20\x01\x0d\xb8\x00\x01\x00\x01\x40\x20\x01\x0d' \
b'\xb8\x00\x01\x00\x00'
value_parsed = IPv6Unicast.parse(nlri_data)
value_hoped = [
'::2001:db8:1:2/64', '::2001:db8:1:1/64', '::2001:db8:1:0/64'
]
self.assertEqual(value_hoped, value_parsed)
def test_parse(self):
nlri_data = b'\x80\x20\x01\x32\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x40\x20\x01\x32' \
b'\x32\x00\x01\x00\x00\x7f\x20\x01\x48\x37\x16\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'
value_parsed = IPv6Unicast().parse(nlri_data)
value_hoped = [
'2001:3232::1/128', '::2001:3232:1:0/64', '2001:4837:1632::2/127'
]
self.assertEqual(value_hoped, value_parsed)
def construct(cls, value):
"""Construct a attribute
:param value: python dictionary
{'afi_safi': (1,128),
'nexthop': {},
'nlri': []
"""
afi, safi = value['afi_safi']
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST: # MPLS VPN
pass
elif safi == safn.SAFNUM_FSPEC_RULE: # BGP Flow spec
try:
try:
nexthop = netaddr.IPAddress(value['nexthop']).packed
except netaddr.core.AddrFormatError:
nexthop = ''
nlri = IPv4FlowSpec.construct(value=value['nlri'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + \
struct.pack('!B', len(nexthop)) + nexthop + b'\x00' + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
except Exception as e:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' % e,
data=value
)
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
# ipv6 unicast
elif afi == afn.AFNUM_INET6:
if safi == safn.SAFNUM_UNICAST:
nexthop_len = 16
nexthop_bin = netaddr.IPAddress(value['nexthop']).packed
if value.get('linklocal_nexthop'):
nexthop_len *= 2
nexthop_bin += netaddr.IPAddress(value['linklocal_nexthop']).packed
nlri_bin = IPv6Unicast.construct(nlri_list=value['nlri'])
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + struct.pack('!B', nexthop_len) + \
nexthop_bin + b'\x00' + nlri_bin
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID)\
+ struct.pack('!B', len(attr_value)) + attr_value
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
def parse(cls, value):
try:
afi, safi = struct.unpack('!HB', value[0:3])
except Exception:
raise excep.UpdateMessageError(sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data='')
nlri_bin = value[3:]
# for IPv4
if afi == afn.AFNUM_INET:
# VPNv4
if safi == safn.SAFNUM_LAB_VPNUNICAST:
nlri = IPv4MPLSVPN.parse(nlri_bin, iswithdraw=True)
return dict(afi_safi=(afi, safi), withdraw=nlri)
# BGP flow spec
elif safi == safn.SAFNUM_FSPEC_RULE:
# if nlri length is greater than 240 bytes, it is encoded over 2 bytes
withdraw_list = []
while nlri_bin:
length = ord(nlri_bin[0])
if length >> 4 == 0xf and len(nlri_bin) > 2:
length = struct.unpack('!H', nlri_bin[:2])[0]
nlri_tmp = nlri_bin[2: length + 2]
nlri_bin = nlri_bin[length + 2:]
else:
nlri_tmp = nlri_bin[1: length + 1]
nlri_bin = nlri_bin[length + 1:]
nlri = IPv4FlowSpec.parse(nlri_tmp)
if nlri:
withdraw_list.append(nlri)
return dict(afi_safi=(afi, safi), withdraw=withdraw_list)
else:
return dict(afi_safi=(afn.AFNUM_INET, safi), withdraw=repr(nlri_bin))
# for ipv6
elif afi == afn.AFNUM_INET6:
# for ipv6 unicast
if safi == safn.SAFNUM_UNICAST:
return dict(afi_safi=(afi, safi), withdraw=IPv6Unicast.parse(nlri_data=nlri_bin))
elif safi == safn.SAFNUM_LAB_VPNUNICAST:
return dict(afi_safi=(afi, safi), withdraw=IPv6MPLSVPN.parse(value=nlri_bin, iswithdraw=True))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
# for evpn
if safi == safn.SAFNUM_EVPN:
return dict(afi_safi=(afi, safi), withdraw=EVPN.parse(nlri_data=nlri_bin))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
else:
return dict(afi_safi=(afi, safi), withdraw=repr(nlri_bin))
def construct(cls, value):
"""Construct a attribute
:param value: python dictionary
{'afi_safi': (1,128),
'withdraw': []
"""
afi, safi = value['afi_safi']
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST: # MPLS VPN
pass
elif safi == safn.SAFNUM_FSPEC_RULE:
try:
nlri = IPv4FlowSpec().construct(value=value['withdraw'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + \
nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
pass
except Exception:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes',
data=value
)
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
elif afi == afn.AFNUM_INET6:
if safi == safn.SAFNUM_UNICAST:
nlri = IPv6Unicast.construct(nlri_list=value['withdraw'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
def construct(cls, value):
"""Construct a attribute
:param value: python dictionary
{'afi_safi': (1,128),
'withdraw': []
"""
afi, safi = value['afi_safi']
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST: # MPLS VPN
nlri = IPv4MPLSVPN.construct(value['withdraw'], iswithdraw=True)
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
elif safi == safn.SAFNUM_FSPEC_RULE:
try:
nlri_list = value.get('withdraw') or []
if not nlri_list:
return None
nlri_hex = b''
for nlri in nlri_list:
nlri_hex += IPv4FlowSpec.construct(value=nlri)
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri_hex
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
except Exception:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes',
data=value
)
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
elif afi == afn.AFNUM_INET6:
if safi == safn.SAFNUM_UNICAST:
nlri = IPv6Unicast.construct(nlri_list=value['withdraw'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
elif safi == safn.SAFNUM_LAB_VPNUNICAST:
nlri = IPv6MPLSVPN.construct(value=value['withdraw'], iswithdraw=True)
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
# for evpn
if safi == safn.SAFNUM_EVPN:
nlri = EVPN.construct(nlri_list=value['withdraw'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
def parse(cls, value):
try:
afi, safi, nexthop_length = struct.unpack('!HBB', value[0:4])
nexthop_bin = value[4:4 + nexthop_length]
nlri_bin = value[5 + nexthop_length:]
except Exception:
# error when lenght is wrong
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=repr(value))
# Address Family IPv4
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST:
# MPLS VPN
# parse nexthop
rd_bin = nexthop_bin[0:8]
rd_type = struct.unpack('!H', rd_bin[0:2])[0]
rd_value_bin = rd_bin[2:]
if rd_type == 0:
asn, an = struct.unpack('!HI', rd_value_bin)
ipv4 = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin[8:]), 16)))
nexthop = {'rd': '%s:%s' % (asn, an), 'str': ipv4}
# TODO(xiaoquwl) for other RD type decoding
else:
nexthop = repr(nexthop_bin[8:])
# parse nlri
nlri = IPv4MPLSVPN.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
elif safi == safn.SAFNUM_FSPEC_RULE:
# if nlri length is greater than 240 bytes, it is encoded over 2 bytes
nlri_list = []
while nlri_bin:
length = ord(nlri_bin[0])
if length >> 4 == 0xf and len(nlri_bin) > 2:
length = struct.unpack('!H', nlri_bin[:2])[0]
nlri_tmp = nlri_bin[2: length + 2]
nlri_bin = nlri_bin[length + 2:]
else:
nlri_tmp = nlri_bin[1: length + 1]
nlri_bin = nlri_bin[length + 1:]
nlri = IPv4FlowSpec.parse(nlri_tmp)
if nlri:
nlri_list.append(nlri)
if nexthop_bin:
nexthop = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin), 16)))
else:
nexthop = ''
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri_list)
else:
nlri = repr(nlri_bin)
# # Address Family IPv6
elif afi == afn.AFNUM_INET6:
# IPv6 unicast
if safi == safn.SAFNUM_UNICAST:
# decode nexthop
# RFC 2545
# The value of the Length of Next Hop Network Address field on a
# MP_REACH_NLRI attribute shall be set to 16, when only a global
# address is present, or 32 if a link-local address is also included in
# the Next Hop field.
#
# The link-local address shall be included in the Next Hop field if and
# only if the BGP speaker shares a common subnet with the entity
# identified by the global IPv6 address carried in the Network Address
# of Next Hop field and the peer the route is being advertised to.
nexthop_addrlen = 16
has_link_local = False
nexthop = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin[:nexthop_addrlen]), 16)))
if len(nexthop_bin) == 2 * nexthop_addrlen:
# has link local address
has_link_local = True
linklocal_nexthop = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin[nexthop_addrlen:]), 16)))
nlri = IPv6Unicast.parse(nlri_bin)
if has_link_local:
return dict(afi_safi=(afi, safi), nexthop=nexthop, linklocal_nexthop=linklocal_nexthop, nlri=nlri)
else:
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
elif safi == safn.SAFNUM_LAB_VPNUNICAST:
# IPv6 MPLS VPN
# parse nexthop
rd_bin = nexthop_bin[0:8]
rd_type = struct.unpack('!H', rd_bin[0:2])[0]
rd_value_bin = rd_bin[2:]
if rd_type == 0:
asn, an = struct.unpack('!HI', rd_value_bin)
ipv6 = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin[8:]), 16)))
nexthop = {'rd': '%s:%s' % (asn, an), 'str': ipv6}
# TODO(xiaoquwl) for other RD type decoding
else:
nexthop = repr(nexthop_bin[8:])
# parse nlri
nlri = IPv6MPLSVPN.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
else:
return dict(afi_safi=(afi, safi), nexthop=nexthop_bin, nlri=nlri_bin)
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
if safi == safn.SAFNUM_EVPN:
nexthop = str(netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin), 16)))
nlri = EVPN.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
else:
nlri = repr(nlri_bin)
else:
nlri = repr(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop_bin, nlri=nlri_bin)
def construct(cls, value):
"""Construct a attribute
:param value: python dictionary
{'afi_safi': (1,128),
'withdraw': []
"""
afi, safi = value['afi_safi']
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST: # MPLS VPN
nlri = IPv4MPLSVPN.construct(value['withdraw'], iswithdraw=True)
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
elif safi == safn.SAFNUM_FSPEC_RULE:
try:
nlri_list = value.get('withdraw') or []
if not nlri_list:
return None
nlri_hex = b''
for nlri in nlri_list:
nlri_hex += IPv4FlowSpec.construct(value=nlri)
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri_hex
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
except Exception:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes',
data=value
)
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
elif afi == afn.AFNUM_INET6:
if safi == safn.SAFNUM_UNICAST:
nlri = IPv6Unicast.construct(nlri_list=value['withdraw'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
elif safi == safn.SAFNUM_LAB_VPNUNICAST:
nlri = IPv6MPLSVPN.construct(value=value['withdraw'], iswithdraw=True)
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
# for evpn
if safi == safn.SAFNUM_EVPN:
nlri = EVPN.construct(nlri_list=value['withdraw'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
else:
return None
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family',
data=value)
def test_construct_nlri(self):
nlri_list = ['::2001:db8:1:2/64', '::2001:db8:1:1/64', '::2001:db8:1:0/64']
value_hex = IPv6Unicast.construct(nlri_list)
value_hoped = b'\x40\x20\x01\x0d\xb8\x00\x01\x00\x02\x40\x20\x01\x0d\xb8\x00\x01\x00\x01\x40\x20\x01\x0d' \
b'\xb8\x00\x01\x00\x00'
self.assertEqual(value_hoped, value_hex)
def test_construct_nlri_2(self):
nlri_list = ['2001:3232::1/128', '::2001:3232:1:0/64', '2001:4837:1632::2/127']
value_hex = IPv6Unicast.construct(nlri_list)
value_hoped = b'\x80\x20\x01\x32\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x40\x20\x01\x32' \
b'\x32\x00\x01\x00\x00\x7f\x20\x01\x48\x37\x16\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'
self.assertEqual(value_hoped, value_hex)
def construct(cls, value):
"""Construct a attribute
:param value: python dictionary
{'afi_safi': (1,128),
'nexthop': {},
'nlri': []
"""
afi, safi = value['afi_safi']
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST: # MPLS VPN
nexthop_hex = cls.construct_mpls_vpn_nexthop(value['nexthop'])
nlri_hex = IPv4MPLSVPN.construct(value['nlri'])
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) +\
struct.pack('!B', len(nexthop_hex)) + nexthop_hex + b'\x00' + nlri_hex
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
elif safi == safn.SAFNUM_FSPEC_RULE: # BGP Flow spec
try:
try:
nexthop = netaddr.IPAddress(value['nexthop']).packed
except netaddr.core.AddrFormatError:
nexthop = ''
nlri = IPv4FlowSpec.construct(value=value['nlri'])
if nlri:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + \
struct.pack('!B', len(nexthop)) + nexthop + b'\x00' + nlri
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
except Exception as e:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' % e,
data=value)
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family', data=value)
# ipv6 unicast
elif afi == afn.AFNUM_INET6:
if safi == safn.SAFNUM_LAB_VPNUNICAST: # MPLS VPN
nexthop_hex = cls.construct_mpls_vpn_nexthop(value['nexthop'])
nlri_hex = IPv6MPLSVPN.construct(value['nlri'])
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) +\
struct.pack('!B', len(nexthop_hex)) + nexthop_hex + b'\x00' + nlri_hex
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(attr_value)) + attr_value
elif safi == safn.SAFNUM_UNICAST:
nexthop_len = 16
nexthop_bin = netaddr.IPAddress(value['nexthop']).packed
if value.get('linklocal_nexthop'):
nexthop_len *= 2
nexthop_bin += netaddr.IPAddress(
value['linklocal_nexthop']).packed
nlri_bin = IPv6Unicast.construct(nlri_list=value['nlri'])
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + struct.pack('!B', nexthop_len) + \
nexthop_bin + b'\x00' + nlri_bin
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID)\
+ struct.pack('!B', len(attr_value)) + attr_value
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
if safi == safn.SAFNUM_EVPN:
nexthop_bin = netaddr.IPAddress(value['nexthop']).packed
nlri_bin = EVPN.construct(nlri_list=value['nlri'])
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + struct.pack('!B', len(nexthop_bin)) + \
nexthop_bin + b'\x00' + nlri_bin
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID)\
+ struct.pack('!B', len(attr_value)) + attr_value
else:
raise excep.ConstructAttributeFailed(
reason='unsupport this sub address family', data=value)
def parse(cls, value):
try:
afi, safi, nexthop_length = struct.unpack('!HBB', value[0:4])
nexthop_bin = value[4:4 + nexthop_length]
nlri_bin = value[5 + nexthop_length:]
except Exception:
# error when lenght is wrong
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=repr(value))
# Address Family IPv4
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST:
# MPLS VPN
# parse nexthop
rd_bin = nexthop_bin[0:8]
rd_type = struct.unpack('!H', rd_bin[0:2])[0]
rd_value_bin = rd_bin[2:]
if rd_type == 0:
asn, an = struct.unpack('!HI', rd_value_bin)
ipv4 = str(
netaddr.IPAddress(
int(binascii.b2a_hex(nexthop_bin[8:]), 16)))
nexthop = {'rd': '%s:%s' % (asn, an), 'str': ipv4}
# TODO(xiaoquwl) for other RD type decoding
else:
nexthop = repr(nexthop_bin[8:])
# parse nlri
nlri = IPv4MPLSVPN.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
elif safi == safn.SAFNUM_FSPEC_RULE:
# if nlri length is greater than 240 bytes, it is encoded over 2 bytes
if len(nlri_bin) >= 240:
nlri_bin = nlri_bin[2:]
else:
nlri_bin = nlri_bin[1:]
nlri = IPv4FlowSpec.parse(nlri_bin)
return dict(afi_safi=(afi, safi),
nexthop=nexthop_bin,
nlri=nlri)
else:
nlri = repr(nlri_bin)
# # Address Family IPv6
elif afi == afn.AFNUM_INET6:
# IPv6 unicast
if safi == safn.SAFNUM_UNICAST:
# decode nexthop
# RFC 2545
# The value of the Length of Next Hop Network Address field on a
# MP_REACH_NLRI attribute shall be set to 16, when only a global
# address is present, or 32 if a link-local address is also included in
# the Next Hop field.
#
# The link-local address shall be included in the Next Hop field if and
# only if the BGP speaker shares a common subnet with the entity
# identified by the global IPv6 address carried in the Network Address
# of Next Hop field and the peer the route is being advertised to.
nexthop_addrlen = 16
has_link_local = False
nexthop = str(
netaddr.IPAddress(
int(binascii.b2a_hex(nexthop_bin[:nexthop_addrlen]),
16)))
if len(nexthop_bin) == 2 * nexthop_addrlen:
# has link local address
has_link_local = True
linklocal_nexthop = str(
netaddr.IPAddress(
int(
binascii.b2a_hex(
nexthop_bin[nexthop_addrlen:]), 16)))
nlri = IPv6Unicast.parse(nlri_bin)
if has_link_local:
return dict(afi_safi=(afi, safi),
nexthop=nexthop,
linklocal_nexthop=linklocal_nexthop,
nlri=nlri)
else:
return dict(afi_safi=(afi, safi),
nexthop=nexthop,
nlri=nlri)
elif safi == safn.SAFNUM_LAB_VPNUNICAST:
# IPv6 MPLS VPN
# parse nexthop
rd_bin = nexthop_bin[0:8]
rd_type = struct.unpack('!H', rd_bin[0:2])[0]
rd_value_bin = rd_bin[2:]
if rd_type == 0:
asn, an = struct.unpack('!HI', rd_value_bin)
ipv6 = str(
netaddr.IPAddress(
int(binascii.b2a_hex(nexthop_bin[8:]), 16)))
nexthop = {'rd': '%s:%s' % (asn, an), 'str': ipv6}
# TODO(xiaoquwl) for other RD type decoding
else:
nexthop = repr(nexthop_bin[8:])
# parse nlri
nlri = IPv6MPLSVPN.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
else:
return dict(afi_safi=(afi, safi),
nexthop=nexthop_bin,
nlri=nlri_bin)
# for l2vpn
elif afi == afn.AFNUM_L2VPN:
if safi == safn.SAFNUM_EVPN:
nexthop = str(
netaddr.IPAddress(int(binascii.b2a_hex(nexthop_bin), 16)))
nlri = EVPN.parse(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
else:
nlri = repr(nlri_bin)
else:
nlri = repr(nlri_bin)
return dict(afi_safi=(afi, safi), nexthop=nexthop_bin, nlri=nlri_bin)
def test_parse_withdraw(self):
nlri_data = b'\x40\x20\x01\x0d\xb8\x00\x01\x00\x02\x40\x20\x01\x0d\xb8\x00\x01\x00\x01\x40\x20\x01\x0d' \
b'\xb8\x00\x01\x00\x00'
value_parsed = IPv6Unicast.parse(nlri_data)
value_hoped = ['::2001:db8:1:2/64', '::2001:db8:1:1/64', '::2001:db8:1:0/64']
self.assertEqual(value_hoped, value_parsed)
