def read_routes6():
"""Return a list of IPv6 routes than can be used by Scapy."""
# Call netstat to retrieve IPv6 routes
fd_netstat = os.popen("netstat -rn -f inet6")
# List interfaces IPv6 addresses
lifaddr = in6_getifaddr()
if not lifaddr:
return []
# Routes header information
got_header = False
mtu_present = False
prio_present = False
# Parse the routes
routes = []
for line in fd_netstat.readlines():
# Parse the routes header and try to identify extra columns
if not got_header:
if "Destination" == line[:11]:
got_header = True
mtu_present = "Mtu" in line
prio_present = "Prio" in line
continue
# Parse a route entry according to the operating system
splitted_line = line.split()
if OPENBSD or NETBSD:
index = 5 + mtu_present + prio_present
if len(splitted_line) < index:
warning("Not enough columns in route entry !")
continue
destination, next_hop, flags = splitted_line[:3]
dev = splitted_line[index]
else:
# FREEBSD or DARWIN
if len(splitted_line) < 4:
warning("Not enough columns in route entry !")
continue
destination, next_hop, flags, dev = splitted_line[:4]
# XXX: TODO: add metrics for unix.py (use -e option on netstat)
metric = 1
# Check flags
if not "U" in flags: # usable route
continue
if "R" in flags: # Host or net unreachable
continue
if "m" in flags: # multicast address
# Note: multicast routing is handled in Route6.route()
continue
# Replace link with the default route in next_hop
if "link" in next_hop:
next_hop = "::"
# Default prefix length
destination_plen = 128
# Extract network interface from the zone id
if '%' in destination:
destination, dev = destination.split('%')
if '/' in dev:
# Example: fe80::%lo0/64 ; dev = "lo0/64"
dev, destination_plen = dev.split('/')
if '%' in next_hop:
next_hop, dev = next_hop.split('%')
# Ensure that the next hop is a valid IPv6 address
if not in6_isvalid(next_hop):
# Note: the 'Gateway' column might contain a MAC address
next_hop = "::"
# Modify parsed routing entries
# Note: these rules are OS specific and may evolve over time
if destination == "default":
destination, destination_plen = "::", 0
elif '/' in destination:
# Example: fe80::/10
destination, destination_plen = destination.split('/')
if '/' in dev:
# Example: ff02::%lo0/32 ; dev = "lo0/32"
dev, destination_plen = dev.split('/')
# Check route entries parameters consistency
if not in6_isvalid(destination):
warning("Invalid destination IPv6 address in route entry !")
continue
try:
destination_plen = int(destination_plen)
except:
warning("Invalid IPv6 prefix length in route entry !")
continue
if in6_ismlladdr(destination) or in6_ismnladdr(destination):
# Note: multicast routing is handled in Route6.route()
continue
if LOOPBACK_NAME in dev:
# Handle ::1 separately
cset = ["::1"]
next_hop = "::"
else:
# Get possible IPv6 source addresses
devaddrs = (x for x in lifaddr if x[2] == dev)
cset = construct_source_candidate_set(destination, destination_plen, devaddrs)
if len(cset):
routes.append((destination, destination_plen, next_hop, dev, cset, metric))
fd_netstat.close()
return routes
def read_routes6():
"""Return a list of IPv6 routes than can be used by Scapy."""
# Call netstat to retrieve IPv6 routes
fd_netstat = os.popen("netstat -rn -f inet6")
# List interfaces IPv6 addresses
lifaddr = in6_getifaddr()
if not lifaddr:
return []
# Routes header information
got_header = False
mtu_present = False
prio_present = False
# Parse the routes
routes = []
for line in fd_netstat.readlines():
# Parse the routes header and try to identify extra columns
if not got_header:
if "Destination" == line[:11]:
got_header = True
mtu_present = "Mtu" in line
prio_present = "Prio" in line
continue
# Parse a route entry according to the operating system
splitted_line = line.split()
if OPENBSD or NETBSD:
index = 5 + mtu_present + prio_present
if len(splitted_line) < index:
warning("Not enough columns in route entry !")
continue
destination, next_hop, flags = splitted_line[:3]
dev = splitted_line[index]
else:
# FREEBSD or DARWIN
if len(splitted_line) < 4:
warning("Not enough columns in route entry !")
continue
destination, next_hop, flags, dev = splitted_line[:4]
# XXX: TODO: add metrics for unix.py (use -e option on netstat)
metric = 1
# Check flags
if "U" not in flags: # usable route
continue
if "R" in flags: # Host or net unreachable
continue
if "m" in flags: # multicast address
# Note: multicast routing is handled in Route6.route()
continue
# Replace link with the default route in next_hop
if "link" in next_hop:
next_hop = "::"
# Default prefix length
destination_plen = 128
# Extract network interface from the zone id
if '%' in destination:
destination, dev = destination.split('%')
if '/' in dev:
# Example: fe80::%lo0/64 ; dev = "lo0/64"
dev, destination_plen = dev.split('/')
if '%' in next_hop:
next_hop, dev = next_hop.split('%')
# Ensure that the next hop is a valid IPv6 address
if not in6_isvalid(next_hop):
# Note: the 'Gateway' column might contain a MAC address
next_hop = "::"
# Modify parsed routing entries
# Note: these rules are OS specific and may evolve over time
if destination == "default":
destination, destination_plen = "::", 0
elif '/' in destination:
# Example: fe80::/10
destination, destination_plen = destination.split('/')
if '/' in dev:
# Example: ff02::%lo0/32 ; dev = "lo0/32"
dev, destination_plen = dev.split('/')
# Check route entries parameters consistency
if not in6_isvalid(destination):
warning("Invalid destination IPv6 address in route entry !")
continue
try:
destination_plen = int(destination_plen)
except Exception:
warning("Invalid IPv6 prefix length in route entry !")
continue
if in6_ismlladdr(destination) or in6_ismnladdr(destination):
# Note: multicast routing is handled in Route6.route()
continue
if LOOPBACK_NAME in dev:
# Handle ::1 separately
cset = ["::1"]
next_hop = "::"
else:
# Get possible IPv6 source addresses
devaddrs = (x for x in lifaddr if x[2] == dev)
cset = construct_source_candidate_set(destination,
destination_plen,
devaddrs) # noqa: E501
if len(cset):
routes.append((destination, destination_plen, next_hop, dev, cset,
metric)) # noqa: E501
fd_netstat.close()
return routes
def route(self, dst, dev=None):
"""
Provide best route to IPv6 destination address, based on Scapy6
internal routing table content.
When a set of address is passed (e.g. 2001:db8:cafe:*::1-5) an address
of the set is used. Be aware of that behavior when using wildcards in
upper parts of addresses !
If 'dst' parameter is a FQDN, name resolution is performed and result
is used.
if optional 'dev' parameter is provided a specific interface, filtering
is performed to limit search to route associated to that interface.
"""
# Transform "2001:db8:cafe:*::1-5:0/120" to one IPv6 address of the set
dst = dst.split("/")[0]
savedst = dst # In case following inet_pton() fails
dst = dst.replace("*", "0")
idx = dst.find("-")
while idx >= 0:
m = (dst[idx:] + ":").find(":")
dst = dst[:idx] + dst[idx + m:]
idx = dst.find("-")
try:
inet_pton(socket.AF_INET6, dst)
except socket.error:
dst = socket.getaddrinfo(savedst, None, socket.AF_INET6)[0][-1][0]
# TODO : Check if name resolution went well
# Use the default interface while dealing with link-local addresses
if dev is None and (in6_islladdr(dst) or in6_ismlladdr(dst)):
dev = conf.iface
# Deal with dev-specific request for cache search
k = dst
if dev is not None:
k = dst + "%%" + (dev if isinstance(dev, six.string_types) else
dev.pcap_name) # noqa: E501
if k in self.cache:
return self.cache[k]
paths = []
# TODO : review all kinds of addresses (scope and *cast) to see
# if we are able to cope with everything possible. I'm convinced
# it's not the case.
# -- arnaud
for p, plen, gw, iface, cset, me in self.routes:
if dev is not None and iface != dev:
continue
if in6_isincluded(dst, p, plen):
paths.append((plen, me, (iface, cset, gw)))
elif (in6_ismlladdr(dst) and in6_islladdr(p)
and in6_islladdr(cset[0])): # noqa: E501
paths.append((plen, me, (iface, cset, gw)))
if not paths:
warning(
"No route found for IPv6 destination %s (no default route?)",
dst) # noqa: E501
return (scapy.consts.LOOPBACK_INTERFACE, "::", "::")
# Sort with longest prefix first
paths.sort(reverse=True, key=lambda x: x[0])
best_plen = paths[0][0]
paths = [x for x in paths if x[0] == best_plen]
res = []
for p in paths: # Here we select best source address for every route
tmp = p[2]
srcaddr = get_source_addr_from_candidate_set(dst, tmp[1])
if srcaddr is not None:
res.append((p[0], p[1], (tmp[0], srcaddr, tmp[2])))
if res == []:
warning(
"Found a route for IPv6 destination '%s', but no possible source address.",
dst) # noqa: E501
return (scapy.consts.LOOPBACK_INTERFACE, "::", "::")
# Tie-breaker: Metrics
paths.sort(key=lambda x: x[1])
paths = [i for i in paths if i[1] == paths[0][1]]
# Symptom : 2 routes with same weight (our weight is plen)
# Solution :
# - dst is unicast global. Check if it is 6to4 and we have a source
# 6to4 address in those available
# - dst is link local (unicast or multicast) and multiple output
# interfaces are available. Take main one (conf.iface6)
# - if none of the previous or ambiguity persists, be lazy and keep
# first one
if len(res) > 1:
tmp = []
if in6_isgladdr(dst) and in6_isaddr6to4(dst):
# TODO : see if taking the longest match between dst and
# every source addresses would provide better results
tmp = [x for x in res if in6_isaddr6to4(x[2][1])]
elif in6_ismaddr(dst) or in6_islladdr(dst):
# TODO : I'm sure we are not covering all addresses. Check that
tmp = [x for x in res if x[2][0] == conf.iface6]
if tmp:
res = tmp
# Fill the cache (including dev-specific request)
k = dst
if dev is not None:
k = dst + "%%" + (dev if isinstance(dev, six.string_types) else
dev.pcap_name) # noqa: E501
self.cache[k] = res[0][2]
return res[0][2]
def route(self, dst="", dev=None, verbose=conf.verb):
# type: (str, Optional[Any], int) -> Tuple[str, str, str]
"""
Provide best route to IPv6 destination address, based on Scapy
internal routing table content.
When a set of address is passed (e.g. ``2001:db8:cafe:*::1-5``) an
address of the set is used. Be aware of that behavior when using
wildcards in upper parts of addresses !
If 'dst' parameter is a FQDN, name resolution is performed and result
is used.
if optional 'dev' parameter is provided a specific interface, filtering
is performed to limit search to route associated to that interface.
"""
dst = dst or "::/0" # Enable route(None) to return default route
# Transform "2001:db8:cafe:*::1-5:0/120" to one IPv6 address of the set
dst = dst.split("/")[0]
savedst = dst # In case following inet_pton() fails
dst = dst.replace("*", "0")
idx = dst.find("-")
while idx >= 0:
m = (dst[idx:] + ":").find(":")
dst = dst[:idx] + dst[idx + m:]
idx = dst.find("-")
try:
inet_pton(socket.AF_INET6, dst)
except socket.error:
dst = socket.getaddrinfo(savedst, None, socket.AF_INET6)[0][-1][0]
# TODO : Check if name resolution went well
# Choose a valid IPv6 interface while dealing with link-local addresses
if dev is None and (in6_islladdr(dst) or in6_ismlladdr(dst)):
dev = conf.iface # default interface
# Check if the default interface supports IPv6!
if dev not in self.ipv6_ifaces and self.ipv6_ifaces:
tmp_routes = [route for route in self.routes
if route[3] != conf.iface]
default_routes = [route for route in tmp_routes
if (route[0], route[1]) == ("::", 0)]
ll_routes = [route for route in tmp_routes
if (route[0], route[1]) == ("fe80::", 64)]
if default_routes:
# Fallback #1 - the first IPv6 default route
dev = default_routes[0][3]
elif ll_routes:
# Fallback #2 - the first link-local prefix
dev = ll_routes[0][3]
else:
# Fallback #3 - the loopback
dev = conf.loopback_name
warning("The conf.iface interface (%s) does not support IPv6! "
"Using %s instead for routing!" % (conf.iface, dev))
# Deal with dev-specific request for cache search
k = dst
if dev is not None:
k = dst + "%%" + dev
if k in self.cache:
return self.cache[k]
paths = [] # type: List[Tuple[int, int, Tuple[str, List[str], str]]]
# TODO : review all kinds of addresses (scope and *cast) to see
# if we are able to cope with everything possible. I'm convinced
# it's not the case.
# -- arnaud
for p, plen, gw, iface, cset, me in self.routes:
if dev is not None and iface != dev:
continue
if in6_isincluded(dst, p, plen):
paths.append((plen, me, (iface, cset, gw)))
elif (in6_ismlladdr(dst) and in6_islladdr(p) and in6_islladdr(cset[0])): # noqa: E501
paths.append((plen, me, (iface, cset, gw)))
if not paths:
if dst == "::1":
return (conf.loopback_name, "::1", "::")
else:
if verbose:
warning("No route found for IPv6 destination %s "
"(no default route?)", dst)
return (conf.loopback_name, "::", "::")
# Sort with longest prefix first then use metrics as a tie-breaker
paths.sort(key=lambda x: (-x[0], x[1]))
best_plen = (paths[0][0], paths[0][1])
paths = [x for x in paths if (x[0], x[1]) == best_plen]
res = [] # type: List[Tuple[int, int, Tuple[str, str, str]]]
for path in paths: # we select best source address for every route
tmp_c = path[2]
srcaddr = get_source_addr_from_candidate_set(dst, tmp_c[1])
if srcaddr is not None:
res.append((path[0], path[1], (tmp_c[0], srcaddr, tmp_c[2])))
if res == []:
warning("Found a route for IPv6 destination '%s', but no possible source address.", dst) # noqa: E501
return (conf.loopback_name, "::", "::")
# Symptom : 2 routes with same weight (our weight is plen)
# Solution :
# - dst is unicast global. Check if it is 6to4 and we have a source
# 6to4 address in those available
# - dst is link local (unicast or multicast) and multiple output
# interfaces are available. Take main one (conf.iface)
# - if none of the previous or ambiguity persists, be lazy and keep
# first one
if len(res) > 1:
tmp = [] # type: List[Tuple[int, int, Tuple[str, str, str]]]
if in6_isgladdr(dst) and in6_isaddr6to4(dst):
# TODO : see if taking the longest match between dst and
# every source addresses would provide better results
tmp = [x for x in res if in6_isaddr6to4(x[2][1])]
elif in6_ismaddr(dst) or in6_islladdr(dst):
# TODO : I'm sure we are not covering all addresses. Check that
tmp = [x for x in res if x[2][0] == conf.iface]
if tmp:
res = tmp
# Fill the cache (including dev-specific request)
k = dst
if dev is not None:
k = dst + "%%" + dev
self.cache[k] = res[0][2]
return res[0][2]
def route(self, dst, dev=None):
"""
Provide best route to IPv6 destination address, based on Scapy6
internal routing table content.
When a set of address is passed (e.g. 2001:db8:cafe:*::1-5) an address
of the set is used. Be aware of that behavior when using wildcards in
upper parts of addresses !
If 'dst' parameter is a FQDN, name resolution is performed and result
is used.
if optional 'dev' parameter is provided a specific interface, filtering
is performed to limit search to route associated to that interface.
"""
# Transform "2001:db8:cafe:*::1-5:0/120" to one IPv6 address of the set
dst = dst.split("/")[0]
savedst = dst # In case following inet_pton() fails
dst = dst.replace("*", "0")
idx = dst.find("-")
while idx >= 0:
m = (dst[idx:] + ":").find(":")
dst = dst[:idx] + dst[idx + m:]
idx = dst.find("-")
try:
inet_pton(socket.AF_INET6, dst)
except socket.error:
dst = socket.getaddrinfo(savedst, None, socket.AF_INET6)[0][-1][0]
# TODO : Check if name resolution went well
# Use the default interface while dealing with link-local addresses
if dev is None and (in6_islladdr(dst) or in6_ismlladdr(dst)):
dev = conf.iface
# Deal with dev-specific request for cache search
k = dst
if dev is not None:
k = dst + "%%" + (dev if isinstance(dev, six.string_types) else dev.pcap_name) # noqa: E501
if k in self.cache:
return self.cache[k]
paths = []
# TODO : review all kinds of addresses (scope and *cast) to see
# if we are able to cope with everything possible. I'm convinced
# it's not the case.
# -- arnaud
for p, plen, gw, iface, cset, me in self.routes:
if dev is not None and iface != dev:
continue
if in6_isincluded(dst, p, plen):
paths.append((plen, me, (iface, cset, gw)))
elif (in6_ismlladdr(dst) and in6_islladdr(p) and in6_islladdr(cset[0])): # noqa: E501
paths.append((plen, me, (iface, cset, gw)))
if not paths:
warning("No route found for IPv6 destination %s (no default route?)", dst) # noqa: E501
return (scapy.consts.LOOPBACK_INTERFACE, "::", "::")
# Sort with longest prefix first
paths.sort(reverse=True, key=lambda x: x[0])
best_plen = paths[0][0]
paths = [x for x in paths if x[0] == best_plen]
res = []
for p in paths: # Here we select best source address for every route
tmp = p[2]
srcaddr = get_source_addr_from_candidate_set(dst, tmp[1])
if srcaddr is not None:
res.append((p[0], p[1], (tmp[0], srcaddr, tmp[2])))
if res == []:
warning("Found a route for IPv6 destination '%s', but no possible source address.", dst) # noqa: E501
return (scapy.consts.LOOPBACK_INTERFACE, "::", "::")
# Tie-breaker: Metrics
paths.sort(key=lambda x: x[1])
paths = [i for i in paths if i[1] == paths[0][1]]
# Symptom : 2 routes with same weight (our weight is plen)
# Solution :
# - dst is unicast global. Check if it is 6to4 and we have a source
# 6to4 address in those available
# - dst is link local (unicast or multicast) and multiple output
# interfaces are available. Take main one (conf.iface6)
# - if none of the previous or ambiguity persists, be lazy and keep
# first one
if len(res) > 1:
tmp = []
if in6_isgladdr(dst) and in6_isaddr6to4(dst):
# TODO : see if taking the longest match between dst and
# every source addresses would provide better results
tmp = [x for x in res if in6_isaddr6to4(x[2][1])]
elif in6_ismaddr(dst) or in6_islladdr(dst):
# TODO : I'm sure we are not covering all addresses. Check that
tmp = [x for x in res if x[2][0] == conf.iface6]
if tmp:
res = tmp
# Fill the cache (including dev-specific request)
k = dst
if dev is not None:
k = dst + "%%" + (dev if isinstance(dev, six.string_types) else dev.pcap_name) # noqa: E501
self.cache[k] = res[0][2]
return res[0][2]
