def decode (afi,bgp): mask = ord_(bgp[0]) size = CIDR.size(mask) if len(bgp) < size+1: raise Notify(3,10,'could not decode CIDR') return bgp[1:size+1] + padding(IP.length(afi)-size), mask
def decode(afi, bgp):
mask = ordinal(bgp[0])
size = CIDR.size(mask)
if len(bgp) < size + 1:
raise Notify(3, 10, 'could not decode CIDR')
return bgp[1:size + 1] + padding(IP.length(afi) - size), mask
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 = ordinal(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', character(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WITHDRAWN: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 AFI %d and SAFI %d' % (afi, safi))
network, bgp = bgp[:size], bgp[size:]
nlri.cidr = CIDR(network + padding(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 = ordinal(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',character(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WITHDRAWN: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 AFI %d and SAFI %d' % (afi,safi))
network,bgp = bgp[:size],bgp[size:]
nlri.cidr = CIDR(network + padding(IP.length(afi)-size),mask)
return nlri,bgp