def main():
from optparse import OptionParser
parser = OptionParser()
parser.add_option("-d", "--devname",
dest="devname", default=None,
help="The name of the tap device to open.")
parser.add_option("-i", "--ifname",
dest="ifname", default=None,
help="The name of the interface to listen on.")
parser.add_option("-g", "--group",
dest="group", default=None,
help="The IPv4 group to use for UML-style multicasts.")
parser.add_option("-p", "--port",
dest="port", default=None,
help="The IPv4 port to use for UML-style multicasts.")
parser.add_option("-a", "--ifaddr",
dest="ifaddr", default=None,
help="The IP address to listen on.")
parser.add_option("-S", "--ether_source",
dest="ether_source", default=None,
help="The Ethernet address to listen on.")
(options, args) = parser.parse_args()
if options.devname is not None:
input = TapConnector(options.devname)
output = input
elif options.group is not None:
if options.port is None:
print "Non-optional argument missing."
return
# XXX Currently, UmlMcast4Connector has to use the same broken
# semantics as QEMU does, to see its traffic -- apps SHOULD be
# joining groups on specific interfaces.
# Note that we'll also end up seeing our own traffic.
#input = UmlMcast4Connector(options.group, options.port, options.ifaddr)
input = UmlMcast4Connector(options.group, options.port, "0.0.0.0")
output = input
elif options.ifname is not None:
input = PcapConnector(options.ifname)
output = PcapConnector(options.ifname)
input.setfilter("udp port 67 or udp port 68")
if options.ifaddr is None or \
options.ether_source is None:
print "Non-optional argument missing."
return
ifaddr = inet_atol(options.ifaddr)
ether_source = ether_atob(options.ether_source)
ip_id = int(random.random() * 32768)
# XXX Should really have an API for extracting our
# local ethernet address.
running = True
while running is True:
packet = input.readpkt()
chain = packet.chain()
# Must have: ether + ip + udp + dhcp.
# UDP checksum ignored. Assume pcap filter above did its job.
if len(chain.packets) < 4 or \
not isinstance(chain.packets[3], dhcpv4):
continue
i_ether = chain.packets[0]
i_ip = chain.packets[1]
i_udp = chain.packets[2]
i_dhcp = chain.packets[3]
# check dhcp htype is ethernet.
# check if dhcp.cid in map.
if i_dhcp.op != pcs.packets.dhcpv4.BOOTREQUEST or \
i_dhcp.htype != pcs.packets.dhcpv4.HTYPE_ETHER or \
i_dhcp.hlen != 6:
continue
#print i_dhcp
chaddr_s = ether_btoa(i_dhcp.chaddr[:i_dhcp.hlen])
if not chaddr_s in map:
print "%s not in map" % chaddr_s
continue
ciaddr = inet_atol(map[chaddr_s]) # from map
dhcp = dhcpv4()
dhcp.op = pcs.packets.dhcpv4.BOOTREPLY
dhcp.htype = pcs.packets.dhcpv4.HTYPE_ETHER
dhcp.hlen = 6
dhcp.hops = 0
dhcp.xid = i_dhcp.xid
dhcp.flags = 0
#dhcp.ciaddr = ciaddr
dhcp.siaddr = ifaddr
# XXX should only fill out if i_dhcp.ciaddr was 0.0.0.0
dhcp.yiaddr = ciaddr
dhcp.chaddr = i_dhcp.chaddr
#dhcp.sname = "myhost"
#dhcp.file = "/vmunix"
#dhcp.options.append(dhcpv4_options.cookie().field())
# server ID.
# XXX Weeiiird!
#sid = dhcpv4_options.dhcp_server_identifier()
#sid.value = ifaddr
#sid.value = inet_atol("0.0.0.0")
#dhcp.options.append(sid.field())
# Subnet mask.
#sm = dhcpv4_options.subnet_mask()
#sm.value = inet_atol("255.255.255.0")
#dhcp.options.append(sm.field())
# Default gateway.
#dg = dhcpv4_options.routers()
#dg.value = ifaddr
#dhcp.options.append(dg.field())
# Add end marker.
#end = dhcpv4_options.end()
#dhcp.options.append(end.field())
# Pad BOOTP payload to 32-bit width.
# XXX BOOTP is problematic because the field which contains
# the options needs to be clamped to 64 bytes in total. This
# means we need to know the encoded length of each option.
# For now, guess it... total length of an RFC-951 payload
# is always 300 bytes.
# this shuts up wireshark.
#padlen = 300 - (len(dhcp.bytes) % 4)
#padlen = 50 - (len(dhcp.bytes) % 4)
#padlen = 4
#pad = dhcpv4_options.pad(padlen)
#dhcp.options.append(pad.field())
# Encapsulate ethernet.
ether = ethernet()
ether.type = 0x0800
ether.src = ether_source
ether.dst = i_dhcp.chaddr[:i_dhcp.hlen]
# Encapsulate IPv4.
ip = ipv4()
ip.version = 4
ip.hlen = 5
ip.tos = 0
ip.id = ip_id
ip.flags = 0x00
ip.offset = 0
ip.ttl = 1
ip.protocol = IPPROTO_UDP
ip.src = ifaddr
ip.dst = ciaddr
ip_id += 1
# Encapsulate UDPv4.
udp = udpv4()
udp.sport = 67
udp.dport = 68
udp.length = len(dhcp.bytes)
udp.checksum = udp.cksum(ip, dhcp.bytes)
# Compute header checksums.
ip.length = len(ip.bytes) + len(udp.bytes) + len(dhcp.bytes)
ip.checksum = ip.cksum()
# Send the lot.
packet = Chain([ether, ip, udp, dhcp])
packet.encode()
out = output.write(packet.bytes, len(packet.bytes))
print out
def test_dhcpv4_encode(self):
p = dhcpv4()
assert (p != None)
p.op = pcs.packets.dhcpv4.BOOTREQUEST
p.htype = pcs.packets.dhcpv4.HTYPE_ETHER
p.hlen = 6 # sizeof(struct ether_addr)
p.hops = 99
p.xid = 0xABADCAFE
p.secs = 123
p.flags = pcs.packets.dhcpv4.BOOTP_BROADCAST
p.ciaddr = inet_atol("1.2.3.4")
p.yiaddr = inet_atol("5.6.7.8")
p.siaddr = inet_atol("9.10.11.12")
p.giaddr = inet_atol("13.14.15.16")
p.chaddr = ether_atob("00:01:02:03:04:05")
p.sname = "fubar"
p.file = "barfu"
# Append DHCP options, which MUST include the cookie.
p.options.append(dhcpv4_options.cookie().field())
# Maximum DHCP message size.
msz = dhcpv4_options.dhcp_max_message_size()
msz.value = 1460
p.options.append(msz.field())
# DHCP message type.
dhcp = dhcpv4_options.dhcp_message_type()
dhcp.value = DHCPDISCOVER
p.options.append(dhcp.field())
# DHCP vendor class.
vc = dhcpv4_options.dhcp_class_identifier()
vc.value = "FreeBSD:amd64:7-CURRENT"
p.options.append(vc.field())
# BOOTP options end marker.
end = dhcpv4_options.end()
p.options.append(end.field())
# Pad BOOTP payload to 32-bit width.
padlen = 4 - (len(p.bytes) % 4)
pad = dhcpv4_options.pad(padlen)
p.options.append(pad.field())
p.encode()
#hd = hexdumper()
#print p
#print hd.dump2(p.bytes)
gotttted = p.bytes
expected = \
"\x01\x01\x06\x63\xAB\xAD\xCA\xFE" \
"\x00\x7B\x80\x00\x01\x02\x03\x04" \
"\x05\x06\x07\x08\x09\x0A\x0B\x0C" \
"\x0D\x0E\x0F\x10\x00\x01\x02\x03" \
"\x04\x05\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x66\x75\x62\x61" \
"\x72\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x62\x61\x72\x66" \
"\x75\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x63\x82\x53\x63" \
"\x39\x02\x05\xB4\x35\x01\x01\x3C" \
"\x17\x46\x72\x65\x65\x42\x53\x44" \
"\x3A\x61\x6D\x64\x36\x34\x3A\x37" \
"\x2D\x43\x55\x52\x52\x45\x4E\x54" \
"\xFF\x00\x00\x00"
self.assertEqual(expected, gotttted, "test encoding")
def test_dhcpv4_encode(self):
p = dhcpv4()
assert (p != None)
p.op = pcs.packets.dhcpv4.BOOTREQUEST
p.htype = pcs.packets.dhcpv4.HTYPE_ETHER
p.hlen = 6 # sizeof(struct ether_addr)
p.hops = 99
p.xid = 0xABADCAFE
p.secs = 123
p.flags = pcs.packets.dhcpv4.BOOTP_BROADCAST
p.ciaddr = inet_atol("1.2.3.4")
p.yiaddr = inet_atol("5.6.7.8")
p.siaddr = inet_atol("9.10.11.12")
p.giaddr = inet_atol("13.14.15.16")
p.chaddr = ether_atob("00:01:02:03:04:05")
p.sname = "fubar"
p.file = "barfu"
# Append DHCP options, which MUST include the cookie.
p.options.append(dhcpv4_options.cookie().field())
# Maximum DHCP message size.
msz = dhcpv4_options.dhcp_max_message_size()
msz.value = 1460
p.options.append(msz.field())
# DHCP message type.
dhcp = dhcpv4_options.dhcp_message_type()
dhcp.value = DHCPDISCOVER
p.options.append(dhcp.field())
# DHCP vendor class.
vc = dhcpv4_options.dhcp_class_identifier()
vc.value = "FreeBSD:amd64:7-CURRENT"
p.options.append(vc.field())
# BOOTP options end marker.
end = dhcpv4_options.end()
p.options.append(end.field())
# Pad BOOTP payload to 32-bit width.
padlen = 4 - (len(p.bytes) % 4)
pad = dhcpv4_options.pad(padlen)
p.options.append(pad.field())
p.encode()
#hd = hexdumper()
#print p
#print hd.dump2(p.bytes)
gotttted = p.bytes
expected = \
"\x01\x01\x06\x63\xAB\xAD\xCA\xFE" \
"\x00\x7B\x80\x00\x01\x02\x03\x04" \
"\x05\x06\x07\x08\x09\x0A\x0B\x0C" \
"\x0D\x0E\x0F\x10\x00\x01\x02\x03" \
"\x04\x05\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x66\x75\x62\x61" \
"\x72\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x62\x61\x72\x66" \
"\x75\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x00\x00\x00\x00" \
"\x00\x00\x00\x00\x63\x82\x53\x63" \
"\x39\x02\x05\xB4\x35\x01\x01\x3C" \
"\x17\x46\x72\x65\x65\x42\x53\x44" \
"\x3A\x61\x6D\x64\x36\x34\x3A\x37" \
"\x2D\x43\x55\x52\x52\x45\x4E\x54" \
"\xFF\x00\x00\x00"
self.assertEqual(expected, gotttted, "test encoding")
def main():
from optparse import OptionParser
parser = OptionParser()
parser.add_option("-d",
"--devname",
dest="devname",
default=None,
help="The name of the tap device to open.")
parser.add_option("-i",
"--ifname",
dest="ifname",
default=None,
help="The name of the interface to listen on.")
parser.add_option("-g",
"--group",
dest="group",
default=None,
help="The IPv4 group to use for UML-style multicasts.")
parser.add_option("-p",
"--port",
dest="port",
default=None,
help="The IPv4 port to use for UML-style multicasts.")
parser.add_option("-a",
"--ifaddr",
dest="ifaddr",
default=None,
help="The IP address to listen on.")
parser.add_option("-S",
"--ether_source",
dest="ether_source",
default=None,
help="The Ethernet address to listen on.")
(options, args) = parser.parse_args()
if options.devname is not None:
input = TapConnector(options.devname)
output = input
elif options.group is not None:
if options.port is None:
print "Non-optional argument missing."
return
# XXX Currently, UmlMcast4Connector has to use the same broken
# semantics as QEMU does, to see its traffic -- apps SHOULD be
# joining groups on specific interfaces.
# Note that we'll also end up seeing our own traffic.
#input = UmlMcast4Connector(options.group, options.port, options.ifaddr)
input = UmlMcast4Connector(options.group, options.port, "0.0.0.0")
output = input
elif options.ifname is not None:
input = PcapConnector(options.ifname)
output = PcapConnector(options.ifname)
input.setfilter("udp port 67 or udp port 68")
if options.ifaddr is None or \
options.ether_source is None:
print "Non-optional argument missing."
return
ifaddr = inet_atol(options.ifaddr)
ether_source = ether_atob(options.ether_source)
ip_id = int(random.random() * 32768)
# XXX Should really have an API for extracting our
# local ethernet address.
running = True
while running is True:
packet = input.readpkt()
chain = packet.chain()
# Must have: ether + ip + udp + dhcp.
# UDP checksum ignored. Assume pcap filter above did its job.
if len(chain.packets) < 4 or \
not isinstance(chain.packets[3], dhcpv4):
continue
i_ether = chain.packets[0]
i_ip = chain.packets[1]
i_udp = chain.packets[2]
i_dhcp = chain.packets[3]
# check dhcp htype is ethernet.
# check if dhcp.cid in map.
if i_dhcp.op != pcs.packets.dhcpv4.BOOTREQUEST or \
i_dhcp.htype != pcs.packets.dhcpv4.HTYPE_ETHER or \
i_dhcp.hlen != 6:
continue
#print i_dhcp
chaddr_s = ether_btoa(i_dhcp.chaddr[:i_dhcp.hlen])
if not chaddr_s in map:
print "%s not in map" % chaddr_s
continue
ciaddr = inet_atol(map[chaddr_s]) # from map
dhcp = dhcpv4()
dhcp.op = pcs.packets.dhcpv4.BOOTREPLY
dhcp.htype = pcs.packets.dhcpv4.HTYPE_ETHER
dhcp.hlen = 6
dhcp.hops = 0
dhcp.xid = i_dhcp.xid
dhcp.flags = 0
#dhcp.ciaddr = ciaddr
dhcp.siaddr = ifaddr
# XXX should only fill out if i_dhcp.ciaddr was 0.0.0.0
dhcp.yiaddr = ciaddr
dhcp.chaddr = i_dhcp.chaddr
#dhcp.sname = "myhost"
#dhcp.file = "/vmunix"
#dhcp.options.append(dhcpv4_options.cookie().field())
# server ID.
# XXX Weeiiird!
#sid = dhcpv4_options.dhcp_server_identifier()
#sid.value = ifaddr
#sid.value = inet_atol("0.0.0.0")
#dhcp.options.append(sid.field())
# Subnet mask.
#sm = dhcpv4_options.subnet_mask()
#sm.value = inet_atol("255.255.255.0")
#dhcp.options.append(sm.field())
# Default gateway.
#dg = dhcpv4_options.routers()
#dg.value = ifaddr
#dhcp.options.append(dg.field())
# Add end marker.
#end = dhcpv4_options.end()
#dhcp.options.append(end.field())
# Pad BOOTP payload to 32-bit width.
# XXX BOOTP is problematic because the field which contains
# the options needs to be clamped to 64 bytes in total. This
# means we need to know the encoded length of each option.
# For now, guess it... total length of an RFC-951 payload
# is always 300 bytes.
# this shuts up wireshark.
#padlen = 300 - (len(dhcp.bytes) % 4)
#padlen = 50 - (len(dhcp.bytes) % 4)
#padlen = 4
#pad = dhcpv4_options.pad(padlen)
#dhcp.options.append(pad.field())
# Encapsulate ethernet.
ether = ethernet()
ether.type = 0x0800
ether.src = ether_source
ether.dst = i_dhcp.chaddr[:i_dhcp.hlen]
# Encapsulate IPv4.
ip = ipv4()
ip.version = 4
ip.hlen = 5
ip.tos = 0
ip.id = ip_id
ip.flags = 0x00
ip.offset = 0
ip.ttl = 1
ip.protocol = IPPROTO_UDP
ip.src = ifaddr
ip.dst = ciaddr
ip_id += 1
# Encapsulate UDPv4.
udp = udpv4()
udp.sport = 67
udp.dport = 68
udp.length = len(dhcp.bytes)
udp.checksum = udp.cksum(ip, dhcp.bytes)
# Compute header checksums.
ip.length = len(ip.bytes) + len(udp.bytes) + len(dhcp.bytes)
ip.checksum = ip.cksum()
# Send the lot.
packet = Chain([ether, ip, udp, dhcp])
packet.encode()
out = output.write(packet.bytes, len(packet.bytes))
print out
