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
{
"0": "old",
"6": 100,
"7": 25102,
"128": [
{
"9": 10,
"1": [
{
"1": {
"label": 2000
}
},
{
"3": {
"node": "10.1.1.1",
"SID": {
"label": 3000,
"TC": 0,
"S": 0,
"TTL": 255
}
}
}
]
}
]
}
"""
policy_hex = b''
policy = value
data = dict([(int(l), r) for (l, r) in policy.items()])
policy_value_hex = b''
items = data.keys()
if bgp_cons.BGP_BSID_PREFERENCE_OLD_OR_NEW not in items:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' %
'please provide the value of TLV encoding',
data={})
for type_tmp in items:
if type_tmp == bgp_cons.BGP_BSID_PREFERENCE_OLD_OR_NEW:
# format of binding sid is same with the mpls label
# the high order 20 bit was truly used as the bsid
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Label | ... |
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# old ios
if data[type_tmp] == 'old':
# Preference Sub-TLV
if bgp_cons.BGPSUB_TLV_PREFERENCE not in items:
if bgp_cons.BGPSUB_TLV_PREFERENCE_NEW in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE_NEW])
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE])
# Binding SID Sub-TLV
if bgp_cons.BGPSUB_TLV_BINDGINGSID not in items:
if bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW not in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID) + struct.pack('!B', 2) +\
b'\x00\x00'
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW] << 12)
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID] << 12)
# new ios
elif data[type_tmp] == 'new':
# Preference Sub-TLV
if bgp_cons.BGPSUB_TLV_PREFERENCE not in items:
if bgp_cons.BGPSUB_TLV_PREFERENCE_NEW in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE_NEW) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE_NEW])
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE_NEW) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE])
# Binding SID Sub-TLV
if bgp_cons.BGPSUB_TLV_BINDGINGSID not in items:
if bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW not in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW) + struct.pack('!B', 2) +\
b'\x00\x00'
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW] << 12)
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID] << 12)
else:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' %
'TLV encoding must be one value of new or old',
data={})
if type_tmp == bgp_cons.BGPSUB_TLV_SIDLIST:
# Sub_TLV segment list
seg_list_hex = b''
for seg_list in data[type_tmp]:
segment_list = dict([(int(l), r)
for (l, r) in seg_list.items()])
weight_hex, seg_hex = cls.construct_weight_and_seg(
segment_list)
seg_list_hex += struct.pack('!B', type_tmp) + struct.pack('!H', len(weight_hex) + len(seg_hex) + 1) +\
b'\x00' + weight_hex + seg_hex
policy_value_hex += seg_list_hex
policy_hex += struct.pack('!H', bgp_cons.BGP_TUNNEL_ENCAPS_SR_TE_POLICY_TYPE) +\
struct.pack('!H', len(policy_value_hex)) + policy_value_hex
return struct.pack('!B', cls.FLAG) + struct.pack(
'!B', cls.ID) + struct.pack('!H', len(policy_hex)) + policy_hex
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 construct(cls, value):
"""Construct a attribute
:param value: python dictionary
{
"0": "old",
"6": 100,
"7": 25102,
"128": [
{
"9": 10,
"1": [
{
"1": {
"label": 2000
}
},
{
"3": {
"node": "10.1.1.1",
"SID": {
"label": 3000,
"TC": 0,
"S": 0,
"TTL": 255
}
}
}
]
}
]
}
"""
policy_hex = b''
policy = value
data = dict([(int(l), r) for (l, r) in policy.items()])
policy_value_hex = b''
items = data.keys()
if bgp_cons.BGP_BSID_PREFERENCE_OLD_OR_NEW not in items:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' % 'please provide the value of TLV encoding',
data={}
)
for type_tmp in items:
if type_tmp == bgp_cons.BGP_BSID_PREFERENCE_OLD_OR_NEW:
# format of binding sid is same with the mpls label
# the high order 20 bit was truly used as the bsid
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# | Label | ... |
# +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
# old ios
if data[type_tmp] == 'old':
# Preference Sub-TLV
if bgp_cons.BGPSUB_TLV_PREFERENCE not in items:
if bgp_cons.BGPSUB_TLV_PREFERENCE_NEW in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE_NEW])
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE])
# Binding SID Sub-TLV
if bgp_cons.BGPSUB_TLV_BINDGINGSID not in items:
if bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW not in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID) + struct.pack('!B', 2) +\
b'\x00\x00'
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW] << 12)
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID] << 12)
# new ios
elif data[type_tmp] == 'new':
# Preference Sub-TLV
if bgp_cons.BGPSUB_TLV_PREFERENCE not in items:
if bgp_cons.BGPSUB_TLV_PREFERENCE_NEW in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE_NEW) + struct.pack('!B', 6) + \
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE_NEW])
# else:
# policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PREFERENCE_NEW) + \
# struct.pack('!B', 6) + b'\x00\x00' \
# + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_PREFERENCE])
# Binding SID Sub-TLV
if bgp_cons.BGPSUB_TLV_BINDGINGSID not in items:
if bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW not in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW) + struct.pack('!B', 2) +\
b'\x00\x00'
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW] << 12)
else:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_BINDGINGSID_NEW) + struct.pack('!B', 6) +\
b'\x00\x00' + struct.pack('!I', data[bgp_cons.BGPSUB_TLV_BINDGINGSID] << 12)
# Explicit NULL Label Policy Sub-TLV
if bgp_cons.BGPSUB_TLV_ENLP_NEW in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_ENLP_NEW) + struct.pack('!B', 3) + \
b'\x00\x00' + struct.pack('!B', data[bgp_cons.BGPSUB_TLV_ENLP_NEW])
# Policy Priority Sub-TLV
if bgp_cons.BGPSUB_TLV_PRIORITY_NEW in items:
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_PRIORITY_NEW) + struct.pack('!B', 2) + \
struct.pack('!B', data[bgp_cons.BGPSUB_TLV_PRIORITY_NEW]) + b'\x00'
# Policy Name Sub-TLV
if bgp_cons.BGPSUB_TLV_POLICYNAME_NEW in items:
length = len(data[bgp_cons.BGPSUB_TLV_POLICYNAME_NEW]) + 1
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_POLICYNAME_NEW) + struct.pack('!H', length) + \
b'\x00' + str(data[bgp_cons.BGPSUB_TLV_POLICYNAME_NEW]).encode('ascii')
# 3.1. The Remote Endpoint Sub-TLV:
if bgp_cons.BGPSUB_TLV_REMOTEENDPOINT_NEW in items:
asn = data[bgp_cons.BGPSUB_TLV_REMOTEENDPOINT_NEW].get('asn')
af = data[bgp_cons.BGPSUB_TLV_REMOTEENDPOINT_NEW].get('afi')
address = data[bgp_cons.BGPSUB_TLV_REMOTEENDPOINT_NEW].get('address')
if af == 'ipv4':
length = 10
af_value = 1
elif af == 'ipv6':
length = 22
af_value = 2
else:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' % 'remote endpoint address family'
' is ipv4 or ipv6',
data={}
)
policy_value_hex += struct.pack('!B', bgp_cons.BGPSUB_TLV_REMOTEENDPOINT_NEW) + struct.pack('!B', length) \
+ struct.pack('!I', asn) + struct.pack('!H', af_value) + netaddr.IPAddress(address).packed
else:
raise excep.ConstructAttributeFailed(
reason='failed to construct attributes: %s' % 'TLV encoding must be one value of new or old',
data={}
)
if type_tmp == bgp_cons.BGPSUB_TLV_SIDLIST:
# Sub_TLV segment list
seg_list_hex = b''
for seg_list in data[type_tmp]:
segment_list = dict([(int(l), r) for (l, r) in seg_list.items()])
weight_hex, seg_hex = cls.construct_weight_and_seg(segment_list)
seg_list_hex += struct.pack('!B', type_tmp) + struct.pack('!H', len(weight_hex) + len(seg_hex) + 1) +\
b'\x00' + weight_hex + seg_hex
policy_value_hex += seg_list_hex
policy_hex += struct.pack('!H', bgp_cons.BGP_TUNNEL_ENCAPS_SR_TE_POLICY_TYPE) +\
struct.pack('!H', len(policy_value_hex)) + policy_value_hex
return struct.pack('!B', cls.FLAG) + struct.pack('!B', cls.ID) + struct.pack('!H', len(policy_hex)) + policy_hex
