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## This file is part of Scapy
## See http://www.secdev.org/projects/scapy for more informations
## Copyright (C) Philippe Biondi <phil@secdev.org>
## This program is published under a GPLv2 license
## Copyright (C) 2005 Guillaume Valadon <guedou@hongo.wide.ad.jp>
## Arnaud Ebalard <arnaud.ebalard@eads.net>
"""
Routing and network interface handling for IPv6.
"""
#############################################################################
#############################################################################
### Routing/Interfaces stuff ###
#############################################################################
#############################################################################
import socket
from config import conf
from utils6 import *
from arch import *
class Route6:
def __init__(self):
self.invalidate_cache()
self.resync()
def invalidate_cache(self):
self.cache = {}
def flush(self):
self.invalidate_cache()
self.routes = []
def resync(self):
# TODO : At the moment, resync will drop existing Teredo routes
# if any. Change that ...
self.invalidate_cache()
self.routes = read_routes6()
if self.routes == []:
log_loading.info("No IPv6 support in kernel")
def __repr__(self):
rtlst = [('Destination', 'Next Hop', "iface", "src candidates")]
for net,msk,gw,iface,cset in self.routes:
rtlst.append(('%s/%i'% (net,msk), gw, iface, ", ".join(cset)))
colwidth = map(lambda x: max(map(lambda y: len(y), x)), apply(zip, rtlst))
fmt = " ".join(map(lambda x: "%%-%ds"%x, colwidth))
rt = "\n".join(map(lambda x: fmt % x, rtlst))
return rt
# Unlike Scapy's Route.make_route() function, we do not have 'host' and 'net'
# parameters. We only have a 'dst' parameter that accepts 'prefix' and
# 'prefix/prefixlen' values.
# WARNING: Providing a specific device will at the moment not work correctly.
def make_route(self, dst, gw=None, dev=None):
"""Internal function : create a route for 'dst' via 'gw'.
"""
prefix, plen = (dst.split("/")+["128"])[:2]
plen = int(plen)
if gw is None:
gw = "::"
if dev is None:
dev, ifaddr, x = self.route(gw)
else:
# TODO: do better than that
# replace that unique address by the list of all addresses
lifaddr = in6_getifaddr()
devaddrs = filter(lambda x: x[2] == dev, lifaddr)
ifaddr = construct_source_candidate_set(prefix, plen, devaddrs, LOOPBACK_NAME)
return (prefix, plen, gw, dev, ifaddr)
def add(self, *args, **kargs):
"""Ex:
add(dst="2001:db8:cafe:f000::/56")
add(dst="2001:db8:cafe:f000::/56", gw="2001:db8:cafe::1")
add(dst="2001:db8:cafe:f000::/64", gw="2001:db8:cafe::1", dev="eth0")
"""
self.invalidate_cache()
self.routes.append(self.make_route(*args, **kargs))
def delt(self, dst, gw=None):
""" Ex:
delt(dst="::/0")
delt(dst="2001:db8:cafe:f000::/56")
delt(dst="2001:db8:cafe:f000::/56", gw="2001:db8:deca::1")
"""
tmp = dst+"/128"
dst, plen = tmp.split('/')[:2]
dst = in6_ptop(dst)
plen = int(plen)
l = filter(lambda x: in6_ptop(x[0]) == dst and x[1] == plen, self.routes)
if gw:
gw = in6_ptop(gw)
l = filter(lambda x: in6_ptop(x[0]) == gw, self.routes)
if len(l) == 0:
warning("No matching route found")
elif len(l) > 1:
warning("Found more than one match. Aborting.")
else:
i=self.routes.index(l[0])
self.invalidate_cache()
del(self.routes[i])
def ifchange(self, iff, addr):
the_addr, the_plen = (addr.split("/")+["128"])[:2]
the_plen = int(the_plen)
naddr = inet_pton(socket.AF_INET6, the_addr)
nmask = in6_cidr2mask(the_plen)
the_net = inet_ntop(socket.AF_INET6, in6_and(nmask,naddr))
for i in range(len(self.routes)):
net,plen,gw,iface,addr = self.routes[i]
if iface != iff:
continue
if gw == '::':
self.routes[i] = (the_net,the_plen,gw,iface,the_addr)
else:
self.routes[i] = (net,the_plen,gw,iface,the_addr)
self.invalidate_cache()
ip6_neigh_cache.flush()
def ifdel(self, iff):
""" removes all route entries that uses 'iff' interface. """
new_routes=[]
for rt in self.routes:
if rt[3] != iff:
new_routes.append(rt)
self.invalidate_cache()
self.routes = new_routes
def ifadd(self, iff, addr):
"""
Add an interface 'iff' with provided address into routing table.
Ex: ifadd('eth0', '2001:bd8:cafe:1::1/64') will add following entry into
Scapy6 internal routing table:
Destination Next Hop iface Def src @
2001:bd8:cafe:1::/64 :: eth0 2001:bd8:cafe:1::1
prefix length value can be omitted. In that case, a value of 128
will be used.
"""
addr, plen = (addr.split("/")+["128"])[:2]
addr = in6_ptop(addr)
plen = int(plen)
naddr = inet_pton(socket.AF_INET6, addr)
nmask = in6_cidr2mask(plen)
prefix = inet_ntop(socket.AF_INET6, in6_and(nmask,naddr))
self.invalidate_cache()
self.routes.append((prefix,plen,'::',iff,[addr]))
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")
l = dst.find("-")
while l >= 0:
m = (dst[l:]+":").find(":")
dst = dst[:l]+dst[l+m:]
l = 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
# 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]
pathes = []
# 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 in self.routes:
if dev is not None and iface != dev:
continue
if in6_isincluded(dst, p, plen):
pathes.append((plen, (iface, cset, gw)))
elif (in6_ismlladdr(dst) and in6_islladdr(p) and in6_islladdr(cset[0])):
pathes.append((plen, (iface, cset, gw)))
if not pathes:
warning("No route found for IPv6 destination %s (no default route?)" % dst)
return (LOOPBACK_NAME, "::", "::") # XXX Linux specific
# Sort with longest prefix first
pathes.sort(reverse=True)
best_plen = pathes[0][0]
pathes = filter(lambda x: x[0] == best_plen, pathes)
res = []
for p in pathes: # Here we select best source address for every route
tmp = p[1]
srcaddr = get_source_addr_from_candidate_set(dst, p[1][1])
if srcaddr is not None:
res.append((p[0], (tmp[0], srcaddr, tmp[2])))
if res == []:
warning("Found a route for IPv6 destination '%s', but no possible source address." % dst)
return (LOOPBACK_NAME, "::", "::") # XXX Linux specific
# 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
# XXX TODO : in a _near_ future, include metric in the game
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 = filter(lambda x: in6_isaddr6to4(x[1][1]), res)
elif in6_ismaddr(dst) or in6_islladdr(dst):
# TODO : I'm sure we are not covering all addresses. Check that
tmp = filter(lambda x: x[1][0] == conf.iface6, res)
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][1]
return res[0][1]
conf.route6 = Route6()
# TBD-hhaim no need for route
#_res = conf.route6.route("::/0")
_res = None;
if _res:
iff, gw, addr = _res
conf.iface6 = iff
del(_res)
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