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:
# 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 test_construct_in_mul_eth_tag(self):
data_hex = b'\x03\x11\x00\x01\xac\x10\x00\x01\x17\x10\x00\x00\x00\x64\x20\xc0\xa8\x00\x01'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_INCLUSIVE_MULTICAST_ETHERNET_TAG,
'value': {
'rd': '172.16.0.1:5904',
'eth_tag_id': 100,
'ip': '192.168.0.1'
}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_in_mul_eth_tag(self):
data_hex = b'\x03\x11\x00\x01\xac\x10\x00\x01\x17\x10\x00\x00\x00\x64\x20\xc0\xa8\x00\x01'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_INCLUSIVE_MULTICAST_ETHERNET_TAG,
'value': {
'rd': '172.16.0.1:5904',
'eth_tag_id': 100,
'ip': '192.168.0.1'
}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_eth_segment(self):
data_hex = b'\x04\x17\x00\x01\xac\x10\x00\x01\x17\x10\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00\x20\xc0\xa8\x00\x01'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_ETHERNET_SEGMENT,
'value': {
'rd': '172.16.0.1:5904',
'esi': 0,
'ip': '192.168.0.1'
}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_eth_segment(self):
data_hex = b'\x04\x17\x00\x01\xac\x10\x00\x01\x17\x10\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00\x20\xc0\xa8\x00\x01'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_ETHERNET_SEGMENT,
'value': {
'rd': '172.16.0.1:5904',
'esi': 0,
'ip': '192.168.0.1'
}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_eth_auto_dis(self):
data_hex = b'\x01\x19\x00\x01\x01\x01\x01\x01\x80\x63\x00\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x64\x00\x00\xa1'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_ETHERNET_AUTO_DISCOVERY,
'value': {
'rd': '1.1.1.1:32867',
'esi': 0,
'eth_tag_id': 100,
'label': [10]
}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_eth_auto_dis(self):
data_hex = b'\x01\x19\x00\x01\x01\x01\x01\x01\x80\x63\x00\x00\x00' \
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x64\x00\x00\xa1'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_ETHERNET_AUTO_DISCOVERY,
'value': {
'rd': '1.1.1.1:32867',
'esi': 0,
'eth_tag_id': 100,
'label': [10]
}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_ip_route_prefix_v4(self):
data_hex = b'\x05\x22\x00\x02\x00\x01\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x01\x18\x01\x01\x01\x00\x01\x01\x01\x01\x00\x00\xa1'
data_list = [{
'type': 5,
'value': {
'esi': 0,
'eth_tag_id': 1,
'gateway': '1.1.1.1',
'label': [10],
'prefix': '1.1.1.0/24',
'rd': '65536:2'}}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_mac_ip_adv(self):
data_hex = b'\x02\x25\x00\x01\xac\x11\x00\x03\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x6c\x30\x00\x11\x22\x33\x44\x55\x20\x0b\x0b\x0b\x01\x00\x00\x00'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_MAC_IP_ADVERTISEMENT,
'value': {
'rd': '172.17.0.3:2',
'mac': '00-11-22-33-44-55',
'eth_tag_id': 108,
'esi': 0,
'ip': '11.11.11.1',
'label': [0]}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_mac_ip_adv(self):
data_hex = b'\x02\x25\x00\x01\xac\x11\x00\x03\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x6c\x30\x00\x11\x22\x33\x44\x55\x20\x0b\x0b\x0b\x01\x00\x00\x00'
data_list = [{
'type': bgp_cons.BGPNLRI_EVPN_MAC_IP_ADVERTISEMENT,
'value': {
'rd': '172.17.0.3:2',
'mac': '00-11-22-33-44-55',
'eth_tag_id': 108,
'esi': 0,
'ip': '11.11.11.1',
'label': [0]}
}]
self.assertEqual(data_hex, EVPN.construct(data_list))
def test_construct_ip_route_prefix_v6(self):
data_hex = b'\x05' \
b'\x3a' \
b'\x00\x02\x00\x01\x00\x00\x00\x02' \
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' \
b'\x00\x00\x00\x01' \
b'\x40' \
b'\x20\x01\x32\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01' \
b'\x20\x01\x32\x32\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01' \
b'\x00\x00\xa1'
data_list = [{
'type': 5,
'value': {
'esi': 0,
'eth_tag_id': 1,
'gateway': '2001:3232::1',
'label': [10],
'prefix': '2001:3232::1/64',
'rd': '65536:2'}}]
self.assertEqual(data_hex, EVPN.construct(data_list))
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 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 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),
'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_hex = b''
for nlri in value['nlri']:
nlri_hex += IPv4FlowSpec.construct(value=nlri)
if nlri_hex:
attr_value = struct.pack('!H', afi) + struct.pack('!B', safi) + \
struct.pack('!B', len(nexthop)) + nexthop + b'\x00' + nlri_hex
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 construct_attributes(attr_dict, asn4=False):
"""
construts BGP Update attirubte.
:param attr_dict: bgp attribute dictionary
:param asn4: support 4 bytes asn or not
"""
attr_raw_hex = b''
for type_code, value in attr_dict.items():
if type_code == bgp_cons.BGPTYPE_ORIGIN:
origin_hex = Origin.construct(value=value)
attr_raw_hex += origin_hex
elif type_code == bgp_cons.BGPTYPE_AS_PATH:
aspath_hex = ASPath.construct(value=value, asn4=asn4)
attr_raw_hex += aspath_hex
elif type_code == bgp_cons.BGPTYPE_NEXT_HOP:
nexthop_hex = NextHop.construct(value=value)
attr_raw_hex += nexthop_hex
elif type_code == bgp_cons.BGPTYPE_MULTI_EXIT_DISC:
med_hex = MED.construct(value=value)
attr_raw_hex += med_hex
elif type_code == bgp_cons.BGPTYPE_LOCAL_PREF:
localpre_hex = LocalPreference.construct(value=value)
attr_raw_hex += localpre_hex
elif type_code == bgp_cons.BGPTYPE_ATOMIC_AGGREGATE:
atomicaggregate_hex = AtomicAggregate.construct(value=value)
attr_raw_hex += atomicaggregate_hex
elif type_code == bgp_cons.BGPTYPE_AGGREGATOR:
aggregator_hex = Aggregator.construct(value=value, asn4=asn4)
attr_raw_hex += aggregator_hex
elif type_code == bgp_cons.BGPTYPE_COMMUNITIES:
community_hex = Community.construct(value=value)
attr_raw_hex += community_hex
elif type_code == bgp_cons.BGPTYPE_ORIGINATOR_ID:
originatorid_hex = OriginatorID.construct(value=value)
attr_raw_hex += originatorid_hex
elif type_code == bgp_cons.BGPTYPE_CLUSTER_LIST:
clusterlist_hex = ClusterList.construct(value=value)
attr_raw_hex += clusterlist_hex
elif type_code == bgp_cons.BGPTYPE_MP_REACH_NLRI:
mpreach_hex = MpReachNLRI().construct(value=value)
attr_raw_hex += mpreach_hex
elif type_code == bgp_cons.BGPTYPE_MP_UNREACH_NLRI:
mpunreach_hex = MpUnReachNLRI.construct(value=value)
attr_raw_hex += mpunreach_hex
elif type_code == bgp_cons.BGPTYPE_EXTENDED_COMMUNITY:
community_ext_hex = ExtCommunity.construct(value=value)
attr_raw_hex += community_ext_hex
elif type_code == bgp_cons.BGPTYPE_PMSI_TUNNEL:
evpn_overlay = EVPN.signal_evpn_overlay(attr_dict)
attr_raw_hex += PMSITunnel.construct(value=value,
evpn_overlay=evpn_overlay)
elif type_code == bgp_cons.BGPTYPE_TUNNEL_ENCAPS_ATTR:
tunnelencap_hex = TunnelEncaps.construct(value=value)
attr_raw_hex += tunnelencap_hex
elif type_code == bgp_cons.BGPTYPE_LARGE_COMMUNITY:
large_community_ext_hex = LargeCommunity.construct(value=value)
attr_raw_hex += large_community_ext_hex
return attr_raw_hex
def parse_attributes(data, asn4=False):
"""
Parses an RFC4271 encoded blob of BGP attributes into a list
:param data:
:param asn4: support 4 bytes asn or not
:return:
"""
attributes = {}
postfix = data
bgpls_pro_id = None
bgpls_attr = None
while len(postfix) > 0:
try:
flags, type_code = struct.unpack('!BB', postfix[:2])
if flags & AttributeFlag.EXTENDED_LENGTH:
attr_len = struct.unpack('!H', postfix[2:4])[0]
attr_value = postfix[4:4 + attr_len]
postfix = postfix[4 + attr_len:] # Next attribute
else: # standard 1-octet length
if isinstance(postfix[2], int):
attr_len = postfix[2]
else:
attr_len = ord(postfix[2])
attr_value = postfix[3:3 + attr_len]
postfix = postfix[3 + attr_len:] # Next attribute
except Exception as e:
LOG.error(e)
error_str = traceback.format_exc()
LOG.debug(error_str)
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_MALFORMED_ATTR_LIST,
data='')
if type_code == bgp_cons.BGPTYPE_ORIGIN:
decode_value = Origin.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_AS_PATH:
decode_value = ASPath.parse(value=attr_value, asn4=asn4)
elif type_code == bgp_cons.BGPTYPE_NEXT_HOP:
decode_value = NextHop.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_MULTI_EXIT_DISC:
decode_value = MED.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_LOCAL_PREF:
decode_value = LocalPreference.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_ATOMIC_AGGREGATE:
decode_value = AtomicAggregate.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_AGGREGATOR:
decode_value = Aggregator.parse(value=attr_value, asn4=asn4)
elif type_code == bgp_cons.BGPTYPE_COMMUNITIES:
decode_value = Community.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_ORIGINATOR_ID:
decode_value = OriginatorID.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_CLUSTER_LIST:
decode_value = ClusterList.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_NEW_AS_PATH:
decode_value = ASPath.parse(value=attr_value, asn4=True)
elif type_code == bgp_cons.BGPTYPE_NEW_AGGREGATOR:
decode_value = Aggregator.parse(value=attr_value, asn4=True)
elif type_code == bgp_cons.BGPTYPE_LARGE_COMMUNITY:
decode_value = LargeCommunity.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_MP_REACH_NLRI:
decode_value = MpReachNLRI.parse(value=attr_value)
if decode_value['nlri'][0] and type(
decode_value['nlri'][0]) is dict:
if decode_value['nlri'][0].get("protocol_id"):
bgpls_pro_id = decode_value['nlri'][0]["protocol_id"]
elif type_code == bgp_cons.BGPTYPE_MP_UNREACH_NLRI:
decode_value = MpUnReachNLRI.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_EXTENDED_COMMUNITY:
decode_value = ExtCommunity.parse(value=attr_value)
elif type_code == bgp_cons.BGPTYPE_PMSI_TUNNEL:
decode_value = PMSITunnel.parse(value=attr_value)
pmsi_hex = attr_value
elif type_code == bgp_cons.BGPTYPE_LINK_STATE:
if bgpls_pro_id:
attributes.update(
LinkState.unpack(bgpls_pro_id=bgpls_pro_id,
data=attr_value).dict())
else:
bgpls_attr = attr_value
continue
else:
decode_value = binascii.b2a_hex(attr_value)
attributes[type_code] = decode_value
if bgpls_attr:
attributes.update(
LinkState.unpack(bgpls_pro_id=bgpls_pro_id,
data=attr_value).dict())
evpn_overlay = EVPN.signal_evpn_overlay(attributes)
if evpn_overlay['evpn'] and evpn_overlay['encap_ec']:
if bgp_cons.BGPTYPE_PMSI_TUNNEL in attributes:
attributes[bgp_cons.BGPTYPE_PMSI_TUNNEL] = PMSITunnel.parse(
value=pmsi_hex, evpn_overlay=evpn_overlay)
return attributes
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)