def send_DHCPv6_Reply(self, pkt):
"""
Sends out the DHCPv6 Reply message.
"""
header = self.build_reply_headers(pkt)
trid = pkt[DHCP6_InfoRequest].trid
srv_duid = header[Ether].src
cli_id = DHCP6OptClientId(duid=pkt[DHCP6OptClientId].duid)
srv_id = DHCP6OptServerId(duid=DUID_LL(lladdr=srv_duid))
sendp(
header / DHCP6_Reply(trid=trid) / cli_id / srv_id,
iface=self.iface,
verbose=False,
)
def craft_dhcp_request(self, hw=None):
"""Generates a DHCPv6 Request packet
Args:
hw (str|bytes, optional): Defaults to MAC of Scapy's `conf.iface`.
Client MAC address to use for DUID LL.
Returns:
scapy.layers.inet.IPv6: DHCPv6 Request packet
"""
if not hw:
_, hw = get_if_raw_hwaddr(conf.iface)
else:
hw = mac_str_to_bytes(hw)
# TODO
# Request Message
# - sent by clients
# - includes a server identifier option
# - the content of Server Identifier option must match server's DUID
# - includes a client identifier option
# - must include an ORO Option (even with hints) p40
# - can includes a reconfigure Accept option indicating whether or
# not the client is willing to accept Reconfigure messages from
# the server (p40)
# - When the server receives a Request message via unicast from a
# client to which the server has not sent a unicast option, the server
# discards the Request message and responds with a Reply message
# containing Status Code option with the value UseMulticast, a Server
# Identifier Option containing the server's DUID, the client
# Identifier option from the client message and no other option.
dhcp_request = (IPv6(dst="ff02::1:2") / UDP(sport=546, dport=547) /
DHCP6_Request(trid=self.xid) /
DHCP6OptServerId(duid=self.server_id) /
DHCP6OptElapsedTime() /
DHCP6OptClientId(duid=DUID_LL(lladdr=hw)) /
DHCP6OptIA_NA(iaid=0))
if settings.DEBUG:
print(dhcp_request.show())
return dhcp_request
def craft_discover(self, hw=None):
"""Generates a DHCPv6 Solicit packet
Args:
hw (str|bytes, optional): Defaults to MAC of Scapy's `conf.iface`.
Client MAC address to use for DUID LL.
Returns:
scapy.layers.inet.IPv6: DHCPv6 Solicit packet
"""
if not hw:
_, hw = get_if_raw_hwaddr(conf.iface)
else:
hw = mac_str_to_bytes(hw)
dhcp_solicit = (IPv6(dst="ff02::1:2") / UDP(sport=546, dport=547) /
DHCP6_Solicit(trid=self.xid) / DHCP6OptElapsedTime() /
DHCP6OptClientId(duid=DUID_LL(lladdr=hw)) /
DHCP6OptIA_NA(iaid=0))
if settings.DEBUG:
print(dhcp_solicit.show())
return dhcp_solicit
def testfunc(child):
iface = os.environ["TAP"]
pkt = wait_for_dhcpv6_pkt(iface)
# the packet was a solicit
assert DHCP6_Solicit in pkt
# check if the sender is the upstream interface of the node
upstream_netif = get_upstream_netif(child)
print(upstream_netif)
upstream_hwaddrs = get_hwaddrs(child, upstream_netif)
assert DHCP6OptClientId in pkt and DUID_LL in pkt[DHCP6OptClientId].duid
assert pkt[DHCP6OptClientId].duid[DUID_LL].lladdr in upstream_hwaddrs
# and it is asking for a prefix delegation
assert DHCP6OptIA_PD in pkt
# reply to solicit with advertise and a prefix provided
trid = pkt[DHCP6_Solicit].trid
srv_duid = "aa:bb:cc:dd:ee:ff"
cli_id = DHCP6OptClientId(duid=pkt[DHCP6OptClientId].duid)
srv_id = DHCP6OptServerId(duid=DUID_LL(lladdr=srv_duid))
prefix = "2001:db8:{:x}:{:x}::".format(random.randint(0, 0xffff),
random.randint(0, 0xffff))
ia_pd = DHCP6OptIA_PD(T1=12000,
T2=13000,
iaid=pkt[DHCP6OptIA_PD].iaid,
iapdopt=[
DHCP6OptIAPrefix(preflft=14000,
validlft=15000,
prefix=prefix,
plen=64)
])
# start sniffer to catch incoming request
sniffer = start_sniffer(iface,
stop_filter=lambda pkt: DHCP6_Request in pkt)
sendp(build_reply_headers(pkt) / DHCP6_Advertise(trid=trid) / cli_id /
srv_id / ia_pd,
iface=iface,
verbose=False)
# wait for request
pkt = wait_for_dhcpv6_pkt(iface, sniffer)
# the packet was indeed a request
assert DHCP6_Request in pkt
# and from the client
assert DHCP6OptClientId in pkt and DUID_LL in pkt[DHCP6OptClientId].duid
assert pkt[DHCP6OptClientId].duid[DUID_LL].lladdr in upstream_hwaddrs
# and it is trying to talk to this server
assert DHCP6OptServerId in pkt and DUID_LL in pkt[DHCP6OptServerId].duid
assert pkt[DHCP6OptServerId].duid[DUID_LL].lladdr == srv_duid
# and is still asking for a prefix delegation
assert DHCP6OptIA_PD in pkt
# reply to request with reply and a prefix provided
trid = pkt[DHCP6_Request].trid
sendp(build_reply_headers(pkt) / DHCP6_Reply(trid=trid) / cli_id / srv_id /
ia_pd,
iface=iface,
verbose=False)
time.sleep(1)
# check if global address was configured
child.sendline("ifconfig {}".format(get_downstream_netif(child)))
# remove one trailing ':' from prefix just to be safe ;-)
child.expect(r"inet6 addr:\s+{}[0-9a-fA-F:]+\s".format(prefix[:-1]))
print("SUCCESS")