def parse(cls, value, asn4=False):
"""
Parse AS PATH attributes.
:param asn4: 4 bytes asn or not
:param value: raw binary balue
"""
# Loop over all path segments
aspath = []
while len(value) > 0:
seg_type, length = struct.unpack('!BB', value[:2])
if seg_type not in [
cls.AS_SET, cls.AS_SEQUENCE, cls.AS_CONFED_SEQUENCE,
cls.AS_CONFED_SET
]:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_MALFORMED_ASPATH,
data=repr(value))
try:
if asn4:
segment = list(
struct.unpack('!%dI' % length,
value[2:2 + length * 4]))
value = value[2 + length * 4:]
else:
segment = list(
struct.unpack('!%dH' % length,
value[2:2 + length * 2]))
value = value[2 + length * 2:]
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data='')
aspath.append((seg_type, segment))
return aspath
def parse(cls, value, asn4=False):
"""
Parse Aggregator attributes.
:param value: raw binary value
:param asn4: support 4 bytes asn or not
"""
if not asn4:
try:
asn = struct.unpack('!H', value[:2])[0]
aggregator = str(netaddr.IPAddress(struct.unpack('!I', value[2:])[0]))
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=value)
else:
# 4 bytes ASN
try:
asn = struct.unpack('!I', value[:4])[0]
aggregator = str(netaddr.IPAddress(struct.unpack('!I', value[4:])[0]))
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=value)
return asn, aggregator
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):
"""
encode BGP nexthop attribute.
:param value: ipv4 format string like 1.1.1.1
"""
try:
if netaddr.IPAddress(value).version == 4:
ip_addr_raw = netaddr.IPAddress(value).packed
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(ip_addr_raw)) + ip_addr_raw
else:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_INVALID_NEXTHOP,
data=value)
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_INVALID_NEXTHOP, data=value)
def parse(cls, value):
"""
Parse originator id
:param value:
"""
if len(value) != 4:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
return str(netaddr.IPAddress(int(binascii.b2a_hex(value[0:4]), 16)))
def parse(cls, value):
"""
parse BGP med attributes
:param value: raw binary value
"""
try:
return struct.unpack('!I', value)[0]
except:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
def parse(cls, value):
"""
parse bgp ATOMIC_AGGREGATE attribute
:param value:
"""
if not value:
return value
else:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_OPTIONAL_ATTR, data=value)
def construct(cls, value):
"""
encode BGP med attributes
:param value:
"""
try:
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', 4) + struct.pack('!I', value)
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data='')
def construct(cls, value):
"""
construct a origin attribute
:param value: 0,1,2
"""
if value not in [cls.IGP, cls.EGP, cls.INCOMPLETE]:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_INVALID_ORIGIN, data='')
length = 1
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', length) + struct.pack('!B', value)
def construct(cls, value):
"""
construct a ORIGINATOR_ID path attribute
:param value: ipv4 format string
"""
try:
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', 4) + netaddr.IPAddress(value).packed
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
def construct(cls, value):
"""construct a ATOMIC_AGGREGATE path attribute
:param value:
"""
if value:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_OPTIONAL_ATTR, data='')
else:
value = 0
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', value)
def parse(cls, value):
"""
parse bgp ATOMIC_AGGREGATE attribute
:param value:
"""
if not value:
# return value
# return str(value, encoding="utf-8")
return bytes.decode(value)
else:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_OPTIONAL_ATTR, data=value)
def parse(cls, value):
"""
Parse BGP nexthop.
:param value: raw binary value
"""
if len(value) % 4 == 0:
next_hop = str(
netaddr.IPAddress(int(binascii.b2a_hex(value[0:4]), 16)))
return next_hop
else:
# Error process
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
def parse(cls, value):
"""
Error process:
(1) the falgs of the ORIGIN attribute must be "well-know,transitive"
(2) If the ORIGIN attribute has an undefined value, then the Error Sub-code
MUST be set to Invalid Origin Attribute. The Data field MUST contain the
unrecognized attribute (type,length, and vlaue)
:param value: raw binary value
"""
orgin = ord(value[0:1])
if orgin not in [cls.IGP, cls.EGP, cls.INCOMPLETE]:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_INVALID_ORIGIN, data=value)
return orgin
def parse_prefix_list(data, addpath=False):
"""
Parses an RFC4271 encoded blob of BGP prefixes into a list
:param data: hex data
:param addpath: support addpath or not
:return: prefix_list
"""
prefixes = []
postfix = data
while len(postfix) > 0:
# for python2 and python3
if addpath:
path_id = struct.unpack('!I', postfix[0:4])[0]
postfix = postfix[4:]
if isinstance(postfix[0], int):
prefix_len = postfix[0]
else:
prefix_len = ord(postfix[0])
if prefix_len > 32:
LOG.warning('Prefix Length larger than 32')
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_INVALID_NETWORK_FIELD,
data=repr(data))
octet_len, remainder = int(prefix_len / 8), prefix_len % 8
if remainder > 0:
# prefix length doesn't fall on octet boundary
octet_len += 1
tmp = postfix[1:octet_len + 1]
# for python2 and python3
if isinstance(postfix[0], int):
prefix_data = [i for i in tmp]
else:
prefix_data = [ord(i) for i in tmp]
# Zero the remaining bits in the last octet if it didn't fall
# on an octet boundary
if remainder > 0:
prefix_data[-1] &= 255 << (8 - remainder)
prefix_data = prefix_data + list(str(0)) * 4
prefix = "%s.%s.%s.%s" % (tuple(
prefix_data[0:4])) + '/' + str(prefix_len)
if not addpath:
prefixes.append(prefix)
else:
prefixes.append({'prefix': prefix, 'path_id': path_id})
# Next prefix
postfix = postfix[octet_len + 1:]
return prefixes
def parse(cls, value):
"""
Parse culster list
:param value
"""
cluster_list = []
if len(value) % 4 != 0:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=repr(value))
while value:
cluster_list.append(str(netaddr.IPAddress(struct.unpack('!I', value[0:4])[0])))
value = value[4:]
return cluster_list
def construct(cls, value):
"""
construct a CLUSTER_LIST path attribute
:param value:
"""
cluster_raw = b''
try:
for cluster in value:
cluster_raw += netaddr.IPAddress(cluster).packed
return struct.pack("!B", cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack("!B", len(cluster_raw)) + cluster_raw
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=struct.pack('B', cls.FLAG))
def construct(cls, value, asn4=False):
"""
Construct AS PATH.
:param asn4: 4byte asn
:param value:
"""
# value example
# [(2, [3257, 31027, 34848, 21465])], or [(3, [64606]), (2, [64624, 65515])]
as_path_raw = b''
for segment in value:
as_seg_raw = b''
seg_type = segment[0]
as_path_list = segment[1]
if seg_type not in [
cls.AS_SET, cls.AS_SEQUENCE, cls.AS_CONFED_SET,
cls.AS_CONFED_SEQUENCE
]:
assert excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_MALFORMED_ASPATH,
data='')
if asn4:
# 4 bytes asn encode
as_count = 0
for asn in as_path_list:
as_count += 1
as_seg_raw += struct.pack('!I', asn)
else:
# 2 bytes asn encode
as_count = 0
for asn in as_path_list:
as_count += 1
as_seg_raw += struct.pack('!H', asn)
as_path_raw += struct.pack('!B', seg_type) + struct.pack(
'!B', as_count) + as_seg_raw
flags = cls.FLAG
if len(as_path_raw) > 255:
flags += AttributeFlag.EXTENDED_LENGTH
return struct.pack('!B', flags) + struct.pack('!B', cls.ID) \
+ struct.pack('!H', len(as_path_raw)) + as_path_raw
else:
return struct.pack('!B', flags) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(as_path_raw)) + as_path_raw
def construct(cls, value):
"""
construct a LARGE COMMUNITY path attribute
:param value:
"""
large_community_hex = b''
for large_community in value:
try:
value = large_community.split(':')
for sub_value in value:
large_community_hex += struct.pack('!I', int(sub_value))
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(large_community_hex)) + large_community_hex
def construct(cls, value, asn4=False):
"""
Construct aggregator.
:param value:
:param asn4:
"""
try:
if asn4:
agg_raw = struct.pack('!I', value[0]) + netaddr.IPAddress(value[1]).packed
else:
agg_raw = struct.pack('!H', value[0]) + netaddr.IPAddress(value[1]).packed
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(agg_raw)) + agg_raw
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=value)
def parse(cls, value):
"""
parse BGP large community.
:param value:
"""
large_community = []
if value:
try:
length = len(value) / 4
value_list = list(struct.unpack('!%di' % length, value))
while value_list:
large_community.append(
"%s:%s:%s" %
(value_list[0], value_list[1], value_list[2]))
value_list = value_list[3:]
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
return large_community
def parse(cls, value):
try:
afi, safi, nexthop_length = struct.unpack('!HBB', value[0:4])
nexthop_data = value[4:4 + nexthop_length]
nlri_data = 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))
if afi == afn.AFNUM_INET:
if safi == safn.SAFNUM_LAB_VPNUNICAST:
nlri = IPv4MPLSVPN.parse(nlri_data)
return {
'afi_safi': (afi, safi),
'nexthop': nexthop_data,
'nlri': nlri
}
def construct(cls, value):
"""
construct a COMMUNITY path attribute
:param value:
"""
community_hex = b''
for community in value:
if community.upper() in bgp_cons.WELL_KNOW_COMMUNITY_STR_2_INT:
value = bgp_cons.WELL_KNOW_COMMUNITY_STR_2_INT[
community.upper()]
community_hex += struct.pack('!I', value)
else:
try:
value = community.split(':')
value = int(value[0]) * 16 * 16 * 16 * 16 + int(value[1])
community_hex += struct.pack('!I', value)
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) \
+ struct.pack('!B', len(community_hex)) + community_hex
def parse(cls, value):
"""
parse BGP community.
:param value:
"""
community = []
if value:
try:
length = len(value) / 2
value_list = list(struct.unpack('!%dH' % length, value))
while value_list:
value_type = value_list[
0] * 16 * 16 * 16 * 16 + value_list[1]
if value_type in bgp_cons.WELL_KNOW_COMMUNITY_INT_2_STR:
community.append(
bgp_cons.WELL_KNOW_COMMUNITY_INT_2_STR[value_type])
else:
community.append("%s:%s" %
(value_list[0], value_list[1]))
value_list = value_list[2:]
except Exception:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
return community
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 parse(cls, value):
"""
Each Extended Community is encoded as an 8-octet quantity, as
follows:
- Type Field : 1 or 2 octets
- Value Field : Remaining octets
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type high | Type low(*) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Value |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parse Extended Community attributes.
:param value : value
"""
# devide every ext community
if len(value) % 8 != 0:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN,
data=value)
ext_community = []
while value:
comm_type, subtype = struct.unpack('!BB', value[0:2])
value_tmp = value[2:8]
comm_code = comm_type * 256 + subtype
# Route Target
if comm_code == bgp_cons.BGP_EXT_COM_RT_0:
# Route Target, Format AS(2bytes):AN(4bytes)
asn, an = struct.unpack('!HI', value_tmp)
ext_community.append([bgp_cons.BGP_EXT_COM_RT_0, '%s:%s' % (asn, an)])
elif comm_code == bgp_cons.BGP_EXT_COM_RT_1:
# Route Target,Format IPv4 address(4bytes):AN(2bytes)
ipv4 = str(netaddr.IPAddress(struct.unpack('!I', value_tmp[0:4])[0]))
an = struct.unpack('!H', value_tmp[4:])[0]
ext_community.append([bgp_cons.BGP_EXT_COM_RT_1, '%s:%s' % (ipv4, an)])
elif comm_code == bgp_cons.BGP_EXT_COM_RT_2:
# Route Target,Format AS(4bytes):AN(2bytes)
asn, an = struct.unpack('!IH', value_tmp)
ext_community.append([bgp_cons.BGP_EXT_COM_RT_2, '%s:%s' % (asn, an)])
# Route Origin
elif comm_code == bgp_cons.BGP_EXT_COM_RO_0:
# Route Origin,Format AS(2bytes):AN(4bytes)
asn, an = struct.unpack('!HI', value_tmp)
ext_community.append([bgp_cons.BGP_EXT_COM_RO_0, '%s:%s' % (asn, an)])
elif comm_code == bgp_cons.BGP_EXT_COM_RO_1:
# Route Origin,Format IP address:AN(2bytes)
ipv4 = str(netaddr.IPAddress(struct.unpack('!I', value_tmp[0:4])[0]))
an = struct.unpack('!H', value_tmp[4:])[0]
ext_community.append([bgp_cons.BGP_EXT_COM_RO_1, '%s:%s' % (ipv4, an)])
elif comm_code == bgp_cons.BGP_EXT_COM_RO_2:
# Route Origin,Format AS(2bytes):AN(4bytes)
asn, an = struct.unpack('!IH', value_tmp)
ext_community.append([bgp_cons.BGP_EXT_COM_RO_2, '%s:%s' % (asn, an)])
# BGP Flow spec
elif comm_code == bgp_cons.BGP_EXT_REDIRECT_NH:
ipv4 = str(netaddr.IPAddress(int(binascii.b2a_hex(value_tmp[0:4]), 16)))
copy_flag = struct.unpack('!H', value_tmp[4:])[0]
ext_community.append([bgp_cons.BGP_EXT_REDIRECT_NH, ipv4, copy_flag])
elif comm_code == bgp_cons.BGP_EXT_TRA_RATE:
asn, rate = struct.unpack('!Hf', value_tmp)
ext_community.append([bgp_cons.BGP_EXT_TRA_RATE, '%s:%s' % (asn, int(rate))])
elif comm_code == bgp_cons.BGP_EXT_TRA_ACTION:
bit_value = parse_bit(value_tmp[-1])
ext_community.append([bgp_cons.BGP_EXT_TRA_ACTION, {'S': bit_value['6'], 'T': bit_value['7']}])
elif comm_code == bgp_cons.BGP_EXT_REDIRECT_VRF:
asn, an = struct.unpack('!HI', value_tmp)
ext_community.append([bgp_cons.BGP_EXT_REDIRECT_VRF, '%s:%s' % (asn, an)])
elif comm_code == bgp_cons.BGP_EXT_TRA_MARK:
mark = struct.unpack('!B', value_tmp[-1])[0]
ext_community.append([bgp_cons.BGP_EXT_TRA_MARK, mark])
# Transitive Opaque
elif comm_code == bgp_cons.BGP_EXT_COM_ENCAP:
ext_community.append([bgp_cons.BGP_EXT_COM_ENCAP, struct.unpack('!I', value_tmp[2:])[0]])
# EVPN
elif comm_code == bgp_cons.BGP_EXT_COM_EVPN_ES_IMPORT:
mac = str(netaddr.EUI(int(binascii.b2a_hex(value_tmp), 16)))
ext_community.append([comm_code, mac])
elif comm_code == bgp_cons.BGP_EXT_COM_EVPN_MAC_MOBIL:
flag = ord(value_tmp[0:1])
seq = struct.unpack('!I', value_tmp[2:])[0]
ext_community.append([comm_code, flag, seq])
elif comm_code == bgp_cons.BGP_EXT_COM_EVPN_ESI_MPLS_LABEL:
flag = ord(value_tmp[0:1])
label = struct.unpack('!L', b'\00'+value_tmp[3:])[0]
label >>= 4
ext_community.append([comm_code, flag, label])
elif comm_code == bgp_cons.BGP_EXT_COM_EVPN_ROUTE_MAC:
ext_community.append([comm_code, str(netaddr.EUI(int(binascii.b2a_hex(value_tmp), 16)))])
else:
ext_community.append([bgp_cons.BGP_EXT_COM_UNKNOW, repr(value_tmp)])
LOG.warn('unknow bgp extended community, type=%s, value=%s', comm_code, repr(value_tmp))
value = value[8:]
return ext_community
def parse(cls, value):
"""
Each Extended Community is encoded as an 8-octet quantity, as
follows:
- Type Field : 1 or 2 octets
- Value Field : Remaining octets
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type high | Type low(*) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Value |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parse Extended Community attributes.
:param value : value
"""
# devide every ext community
if len(value) % 8 != 0:
raise excep.UpdateMessageError(
sub_error=bgp_cons.ERR_MSG_UPDATE_ATTR_LEN, data=value)
ext_community = []
while value:
comm_type, subtype = struct.unpack('!BB', value[0:2])
value_tmp = value[2:8]
comm_code = comm_type * 256 + subtype
# Route Target
if comm_code == bgp_cons.BGP_EXT_COM_RT_0:
# Route Target, Format AS(2bytes):AN(4bytes)
asn, an = struct.unpack('!HI', value_tmp)
ext_community.append(
(bgp_cons.BGP_EXT_COM_RT_0, '%s:%s' % (asn, an)))
elif comm_code == bgp_cons.BGP_EXT_COM_RT_1:
# Route Target,Format IPv4 address(4bytes):AN(2bytes)
ipv4 = str(
netaddr.IPAddress(struct.unpack('!I', value_tmp[0:4])[0]))
an = struct.unpack('!H', value_tmp[4:])[0]
ext_community.append(
(bgp_cons.BGP_EXT_COM_RT_1, '%s:%s' % (ipv4, an)))
elif comm_code == bgp_cons.BGP_EXT_COM_RT_2:
# Route Target,Format AS(4bytes):AN(2bytes)
asn, an = struct.unpack('!IH', value_tmp)
ext_community.append(
(bgp_cons.BGP_EXT_COM_RT_2, '%s:%s' % (asn, an)))
# Route Origin
elif comm_code == bgp_cons.BGP_EXT_COM_RO_0:
# Route Origin,Format AS(2bytes):AN(4bytes)
asn, an = struct.unpack('!HI', value_tmp)
ext_community.append(
(bgp_cons.BGP_EXT_COM_RO_0, '%s:%s' % (asn, an)))
elif comm_code == bgp_cons.BGP_EXT_COM_RO_1:
# Route Origin,Format IP address:AN(2bytes)
ipv4 = str(
netaddr.IPAddress(struct.unpack('!I', value_tmp[0:4])[0]))
an = struct.unpack('!H', value_tmp[4:])[0]
ext_community.append(
(bgp_cons.BGP_EXT_COM_RO_1, '%s:%s' % (ipv4, an)))
elif comm_code == bgp_cons.BGP_EXT_COM_RO_2:
# Route Origin,Format AS(2bytes):AN(4bytes)
asn, an = struct.unpack('!IH', value_tmp)
ext_community.append(
(bgp_cons.BGP_EXT_COM_RO_2, '%s:%s' % (asn, an)))
else:
ext_community.append(
(bgp_cons.BGP_EXT_COM_UNKNOW, repr(value_tmp)))
LOG.warn('unknow bgp extended community, type=%s, value=%s',
comm_code, repr(value_tmp))
value = value[8:]
return ext_community
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
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_LINK_STATE:
decode_value = LinkState.parse(value=attr_value).dict()[29]
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_MP_REACH_NLRI:
decode_value = MpReachNLRI.parse(value=attr_value)
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)
else:
decode_value = binascii.b2a_hex(attr_value)
attributes[type_code] = decode_value
return attributes
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
