def unpack_nlri(cls, afi, safi, bgp, action, addpath):
nlri = cls(afi, safi, action)
if addpath:
nlri.path_info = PathInfo(bgp[:4])
bgp = bgp[4:]
mask = bgp[0]
bgp = bgp[1:]
_, rd_size = Family.size.get((afi, safi), (0, 0))
rd_mask = rd_size * 8
if safi.has_label():
labels = []
while mask - rd_mask >= 24:
label = int(unpack('!L', bytes([0]) + bgp[:3])[0])
bgp = bgp[3:]
mask -= 24 # 3 bytes
# The last 4 bits are the bottom of Stack
# The last bit is set for the last label
labels.append(label >> 4)
# This is a route withdrawal
if label == 0x800000 and action == IN.WITHDRAWN:
break
# This is a next-hop
if label == 0x000000:
break
if label & 1:
break
nlri.labels = Labels(labels)
if rd_size:
mask -= rd_mask # the route distinguisher
rd = bgp[:rd_size]
bgp = bgp[rd_size:]
nlri.rd = RouteDistinguisher(rd)
if mask < 0:
raise Notify(3, 10, 'invalid length in NLRI prefix')
if not bgp and mask:
raise Notify(
3, 10,
'not enough data for the mask provided to decode the NLRI')
size = CIDR.size(mask)
if len(bgp) < size:
raise Notify(
3, 10,
'could not decode route with family %s (AFI %d) %s (SAFI %d)' %
(AFI(afi), int(afi), SAFI(safi), int(safi)))
network, bgp = bgp[:size], bgp[size:]
nlri.cidr = CIDR(network + bytes(IP.length(afi) - size), mask)
return nlri, bgp
def unpack_nlri(cls, afi, safi, bgp, action, addpath):
nlri = cls(afi, safi, action)
if addpath:
nlri.path_info = PathInfo(bgp[:4])
bgp = bgp[4:]
mask = ord(bgp[0])
bgp = bgp[1:]
if cls.has_label():
labels = []
while bgp and mask >= 8:
label = int(unpack('!L', chr(0) + bgp[:3])[0])
bgp = bgp[3:]
mask -= 24 # 3 bytes
# The last 4 bits are the bottom of Stack
# The last bit is set for the last label
labels.append(label >> 4)
# This is a route withdrawal
if label == 0x800000 and action == IN.WITHDRAWN:
break
# This is a next-hop
if label == 0x000000:
break
if label & 1:
break
nlri.labels = Labels(labels)
if cls.has_rd():
mask -= 8 * 8 # the 8 bytes of the route distinguisher
rd = bgp[:8]
bgp = bgp[8:]
nlri.rd = RouteDistinguisher(rd)
if mask < 0:
raise Notify(3, 10, 'invalid length in NLRI prefix')
if not bgp and mask:
raise Notify(
3, 10,
'not enough data for the mask provided to decode the NLRI')
size = CIDR.size(mask)
if len(bgp) < size:
raise Notify(
3, 10, 'could not decode route with AFI %d sand SAFI %d' %
(afi, safi))
network, bgp = bgp[:size], bgp[size:]
padding = '\0' * (IP.length(afi) - size)
nlri.cidr = CIDR(network + padding, mask)
return nlri, bgp
def unpack(cls, afi, safi, bgp, addpath, nexthop, action):
labels, rd, path_identifier, mask, size, prefix, left = NLRI._nlri(
afi, safi, bgp, action, addpath)
nlri = cls(afi, safi, prefix, mask, nexthop, action)
if labels:
nlri.labels = Labels(labels)
if rd:
nlri.rd = RouteDistinguisher(rd)
if path_identifier:
nlri.path_info = PathInfo(None, None, path_identifier)
return len(bgp) - len(left), nlri
def label(tokeniser):
labels = []
value = tokeniser()
if value == '[':
while True:
value = tokeniser()
if value == ']':
break
labels.append(int(value))
else:
labels.append(int(value))
return Labels(labels)
def label (tokeniser):
labels = []
value = tokeniser()
try:
if value == '[':
while True:
value = tokeniser()
if value == ']':
break
labels.append(int(value))
else:
labels.append(int(value))
except ValueError:
raise ValueError('invalid label %s' % value)
return Labels(labels)
def label(self, scope, name, command, tokens):
labels = []
label = tokens.pop(0)
try:
if label == '[':
while True:
try:
label = tokens.pop(0)
except IndexError:
return self.error.set(self.syntax)
if label == ']':
break
labels.append(int(label))
else:
labels.append(int(label))
except ValueError:
return self.error.set(self.syntax)
nlri = scope[-1]['announce'][-1].nlri
if not nlri.safi.has_label():
nlri.safi = SAFI(SAFI.nlri_mpls)
nlri.labels = Labels(labels)
return True
