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inet.py
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inet.py
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# This file is part of Scapy
# See http://www.secdev.org/projects/scapy for more information
# Copyright (C) Philippe Biondi <phil@secdev.org>
# This program is published under a GPLv2 license
"""
IPv4 (Internet Protocol v4).
"""
from __future__ import absolute_import
from __future__ import print_function
import time
import struct
import re
import random
import select
import socket
from collections import defaultdict
from scapy.utils import checksum, do_graph, incremental_label, \
linehexdump, strxor, whois, colgen
from scapy.ansmachine import AnsweringMachine
from scapy.base_classes import Gen, Net
from scapy.data import ETH_P_IP, ETH_P_ALL, DLT_RAW, DLT_RAW_ALT, DLT_IPV4, \
IP_PROTOS, TCP_SERVICES, UDP_SERVICES
from scapy.layers.l2 import Ether, Dot3, getmacbyip, CookedLinux, GRE, SNAP, \
Loopback
from scapy.compat import raw, chb, orb, bytes_encode
from scapy.config import conf
from scapy.extlib import plt, MATPLOTLIB, MATPLOTLIB_INLINED, \
MATPLOTLIB_DEFAULT_PLOT_KARGS
from scapy.fields import (
BitEnumField,
BitField,
ByteEnumField,
ByteField,
ConditionalField,
DestField,
Emph,
FieldLenField,
FieldListField,
FlagsField,
IPField,
IntField,
MultiEnumField,
MultipleTypeField,
PacketListField,
ShortEnumField,
ShortField,
SourceIPField,
StrField,
StrFixedLenField,
StrLenField,
XByteField,
XShortField,
)
from scapy.packet import Packet, bind_layers, bind_bottom_up, NoPayload
from scapy.volatile import RandShort, RandInt, RandBin, RandNum, VolatileValue
from scapy.sendrecv import sr, sr1
from scapy.plist import _PacketList, PacketList, SndRcvList
from scapy.automaton import Automaton, ATMT
from scapy.error import log_runtime, warning
from scapy.pton_ntop import inet_pton
import scapy.as_resolvers
import scapy.modules.six as six
from scapy.modules.six.moves import range
####################
# IP Tools class #
####################
class IPTools(object):
"""Add more powers to a class with an "src" attribute."""
__slots__ = []
def whois(self):
"""whois the source and print the output"""
print(whois(self.src).decode("utf8", "ignore"))
def _ttl(self):
"""Returns ttl or hlim, depending on the IP version"""
return self.hlim if isinstance(self, scapy.layers.inet6.IPv6) else self.ttl # noqa: E501
def ottl(self):
t = sorted([32, 64, 128, 255] + [self._ttl()])
return t[t.index(self._ttl()) + 1]
def hops(self):
return self.ottl() - self._ttl()
_ip_options_names = {0: "end_of_list",
1: "nop",
2: "security",
3: "loose_source_route",
4: "timestamp",
5: "extended_security",
6: "commercial_security",
7: "record_route",
8: "stream_id",
9: "strict_source_route",
10: "experimental_measurement",
11: "mtu_probe",
12: "mtu_reply",
13: "flow_control",
14: "access_control",
15: "encode",
16: "imi_traffic_descriptor",
17: "extended_IP",
18: "traceroute",
19: "address_extension",
20: "router_alert",
21: "selective_directed_broadcast_mode",
23: "dynamic_packet_state",
24: "upstream_multicast_packet",
25: "quick_start",
30: "rfc4727_experiment",
}
class _IPOption_HDR(Packet):
fields_desc = [BitField("copy_flag", 0, 1),
BitEnumField("optclass", 0, 2, {0: "control", 2: "debug"}),
BitEnumField("option", 0, 5, _ip_options_names)]
class IPOption(Packet):
name = "IP Option"
fields_desc = [_IPOption_HDR,
FieldLenField("length", None, fmt="B", # Only option 0 and 1 have no length and value # noqa: E501
length_of="value", adjust=lambda pkt, l:l + 2), # noqa: E501
StrLenField("value", "", length_from=lambda pkt:pkt.length - 2)] # noqa: E501
def extract_padding(self, p):
return b"", p
registered_ip_options = {}
@classmethod
def register_variant(cls):
cls.registered_ip_options[cls.option.default] = cls
@classmethod
def dispatch_hook(cls, pkt=None, *args, **kargs):
if pkt:
opt = orb(pkt[0]) & 0x1f
if opt in cls.registered_ip_options:
return cls.registered_ip_options[opt]
return cls
class IPOption_EOL(IPOption):
name = "IP Option End of Options List"
option = 0
fields_desc = [_IPOption_HDR]
class IPOption_NOP(IPOption):
name = "IP Option No Operation"
option = 1
fields_desc = [_IPOption_HDR]
class IPOption_Security(IPOption):
name = "IP Option Security"
copy_flag = 1
option = 2
fields_desc = [_IPOption_HDR,
ByteField("length", 11),
ShortField("security", 0),
ShortField("compartment", 0),
ShortField("handling_restrictions", 0),
StrFixedLenField("transmission_control_code", "xxx", 3),
]
class IPOption_RR(IPOption):
name = "IP Option Record Route"
option = 7
fields_desc = [_IPOption_HDR,
FieldLenField("length", None, fmt="B",
length_of="routers", adjust=lambda pkt, l:l + 3), # noqa: E501
ByteField("pointer", 4), # 4 is first IP
FieldListField("routers", [], IPField("", "0.0.0.0"),
length_from=lambda pkt:pkt.length - 3)
]
def get_current_router(self):
return self.routers[self.pointer // 4 - 1]
class IPOption_LSRR(IPOption_RR):
name = "IP Option Loose Source and Record Route"
copy_flag = 1
option = 3
class IPOption_SSRR(IPOption_RR):
name = "IP Option Strict Source and Record Route"
copy_flag = 1
option = 9
class IPOption_Stream_Id(IPOption):
name = "IP Option Stream ID"
copy_flag = 1
option = 8
fields_desc = [_IPOption_HDR,
ByteField("length", 4),
ShortField("security", 0), ]
class IPOption_MTU_Probe(IPOption):
name = "IP Option MTU Probe"
option = 11
fields_desc = [_IPOption_HDR,
ByteField("length", 4),
ShortField("mtu", 0), ]
class IPOption_MTU_Reply(IPOption_MTU_Probe):
name = "IP Option MTU Reply"
option = 12
class IPOption_Traceroute(IPOption):
name = "IP Option Traceroute"
option = 18
fields_desc = [_IPOption_HDR,
ByteField("length", 12),
ShortField("id", 0),
ShortField("outbound_hops", 0),
ShortField("return_hops", 0),
IPField("originator_ip", "0.0.0.0")]
class IPOption_Timestamp(IPOption):
name = "IP Option Timestamp"
optclass = 2
option = 4
fields_desc = [_IPOption_HDR,
ByteField("length", None),
ByteField("pointer", 9),
BitField("oflw", 0, 4),
BitEnumField("flg", 1, 4,
{0: "timestamp_only",
1: "timestamp_and_ip_addr",
3: "prespecified_ip_addr"}),
ConditionalField(IPField("internet_address", "0.0.0.0"),
lambda pkt: pkt.flg != 0),
IntField('timestamp', 0)]
def post_build(self, p, pay):
if self.length is None:
p = p[:1] + struct.pack("!B", len(p)) + p[2:]
return p + pay
class IPOption_Address_Extension(IPOption):
name = "IP Option Address Extension"
copy_flag = 1
option = 19
fields_desc = [_IPOption_HDR,
ByteField("length", 10),
IPField("src_ext", "0.0.0.0"),
IPField("dst_ext", "0.0.0.0")]
class IPOption_Router_Alert(IPOption):
name = "IP Option Router Alert"
copy_flag = 1
option = 20
fields_desc = [_IPOption_HDR,
ByteField("length", 4),
ShortEnumField("alert", 0, {0: "router_shall_examine_packet"}), ] # noqa: E501
class IPOption_SDBM(IPOption):
name = "IP Option Selective Directed Broadcast Mode"
copy_flag = 1
option = 21
fields_desc = [_IPOption_HDR,
FieldLenField("length", None, fmt="B",
length_of="addresses", adjust=lambda pkt, l:l + 2), # noqa: E501
FieldListField("addresses", [], IPField("", "0.0.0.0"),
length_from=lambda pkt:pkt.length - 2)
]
TCPOptions = (
{0: ("EOL", None),
1: ("NOP", None),
2: ("MSS", "!H"),
3: ("WScale", "!B"),
4: ("SAckOK", None),
5: ("SAck", "!"),
8: ("Timestamp", "!II"),
14: ("AltChkSum", "!BH"),
15: ("AltChkSumOpt", None),
25: ("Mood", "!p"),
28: ("UTO", "!H"),
34: ("TFO", "!II"),
# RFC 3692
# 253: ("Experiment", "!HHHH"),
# 254: ("Experiment", "!HHHH"),
},
{"EOL": 0,
"NOP": 1,
"MSS": 2,
"WScale": 3,
"SAckOK": 4,
"SAck": 5,
"Timestamp": 8,
"AltChkSum": 14,
"AltChkSumOpt": 15,
"Mood": 25,
"UTO": 28,
"TFO": 34,
})
class RandTCPOptions(VolatileValue):
def __init__(self, size=None):
if size is None:
size = RandNum(1, 5)
self.size = size
def _fix(self):
# Pseudo-Random amount of options
# Random ("NAME", fmt)
rand_patterns = [
random.choice(list(
(opt, fmt) for opt, fmt in six.itervalues(TCPOptions[0])
if opt != 'EOL'
))
for _ in range(self.size)
]
rand_vals = []
for oname, fmt in rand_patterns:
if fmt is None:
rand_vals.append((oname, b''))
else:
# Process the fmt arguments 1 by 1
structs = fmt[1:] if fmt[0] == "!" else fmt
rval = []
for stru in structs:
stru = "!" + stru
if "s" in stru or "p" in stru: # str / chr
v = bytes(RandBin(struct.calcsize(stru)))
else: # int
_size = struct.calcsize(stru)
v = random.randint(0, 2 ** (8 * _size) - 1)
rval.append(v)
rand_vals.append((oname, tuple(rval)))
return rand_vals
def __bytes__(self):
return TCPOptionsField.i2m(None, None, self._fix())
class TCPOptionsField(StrField):
islist = 1
def getfield(self, pkt, s):
opsz = (pkt.dataofs - 5) * 4
if opsz < 0:
log_runtime.info(
"bad dataofs (%i). Assuming dataofs=5", pkt.dataofs
)
opsz = 0
return s[opsz:], self.m2i(pkt, s[:opsz])
def m2i(self, pkt, x):
opt = []
while x:
onum = orb(x[0])
if onum == 0:
opt.append(("EOL", None))
break
if onum == 1:
opt.append(("NOP", None))
x = x[1:]
continue
try:
olen = orb(x[1])
except IndexError:
olen = 0
if olen < 2:
log_runtime.info(
"Malformed TCP option (announced length is %i)", olen
)
olen = 2
oval = x[2:olen]
if onum in TCPOptions[0]:
oname, ofmt = TCPOptions[0][onum]
if onum == 5: # SAck
ofmt += "%iI" % (len(oval) // 4)
if ofmt and struct.calcsize(ofmt) == len(oval):
oval = struct.unpack(ofmt, oval)
if len(oval) == 1:
oval = oval[0]
opt.append((oname, oval))
else:
opt.append((onum, oval))
x = x[olen:]
return opt
def i2h(self, pkt, x):
if not x:
return []
return x
def i2m(self, pkt, x):
opt = b""
for oname, oval in x:
# We check for a (0, b'') or (1, b'') option first
oname = {0: "EOL", 1: "NOP"}.get(oname, oname)
if isinstance(oname, str):
if oname == "NOP":
opt += b"\x01"
continue
elif oname == "EOL":
opt += b"\x00"
continue
elif oname in TCPOptions[1]:
onum = TCPOptions[1][oname]
ofmt = TCPOptions[0][onum][1]
if onum == 5: # SAck
ofmt += "%iI" % len(oval)
_test_isinstance = not isinstance(oval, (bytes, str))
if ofmt is not None and (_test_isinstance or "s" in ofmt):
if not isinstance(oval, tuple):
oval = (oval,)
oval = struct.pack(ofmt, *oval)
else:
warning("Option [%s] unknown. Skipped.", oname)
continue
else:
onum = oname
if not isinstance(onum, int):
warning("Invalid option number [%i]" % onum)
continue
if not isinstance(oval, (bytes, str)):
warning("Option [%i] is not bytes." % onum)
continue
if isinstance(oval, str):
oval = bytes_encode(oval)
opt += chb(onum) + chb(2 + len(oval)) + oval
return opt + b"\x00" * (3 - ((len(opt) + 3) % 4)) # Padding
def randval(self):
return RandTCPOptions()
class ICMPTimeStampField(IntField):
re_hmsm = re.compile("([0-2]?[0-9])[Hh:](([0-5]?[0-9])([Mm:]([0-5]?[0-9])([sS:.]([0-9]{0,3}))?)?)?$") # noqa: E501
def i2repr(self, pkt, val):
if val is None:
return "--"
else:
sec, milli = divmod(val, 1000)
min, sec = divmod(sec, 60)
hour, min = divmod(min, 60)
return "%d:%d:%d.%d" % (hour, min, sec, int(milli))
def any2i(self, pkt, val):
if isinstance(val, str):
hmsms = self.re_hmsm.match(val)
if hmsms:
h, _, m, _, s, _, ms = hmsms.groups()
ms = int(((ms or "") + "000")[:3])
val = ((int(h) * 60 + int(m or 0)) * 60 + int(s or 0)) * 1000 + ms # noqa: E501
else:
val = 0
elif val is None:
val = int((time.time() % (24 * 60 * 60)) * 1000)
return val
class DestIPField(IPField, DestField):
bindings = {}
def __init__(self, name, default):
IPField.__init__(self, name, None)
DestField.__init__(self, name, default)
def i2m(self, pkt, x):
if x is None:
x = self.dst_from_pkt(pkt)
return IPField.i2m(self, pkt, x)
def i2h(self, pkt, x):
if x is None:
x = self.dst_from_pkt(pkt)
return IPField.i2h(self, pkt, x)
class IP(Packet, IPTools):
__slots__ = ["_defrag_pos"]
name = "IP"
fields_desc = [BitField("version", 4, 4),
BitField("ihl", None, 4),
XByteField("tos", 0),
ShortField("len", None),
ShortField("id", 1),
FlagsField("flags", 0, 3, ["MF", "DF", "evil"]),
BitField("frag", 0, 13),
ByteField("ttl", 64),
ByteEnumField("proto", 0, IP_PROTOS),
XShortField("chksum", None),
# IPField("src", "127.0.0.1"),
Emph(SourceIPField("src", "dst")),
Emph(DestIPField("dst", "127.0.0.1")),
PacketListField("options", [], IPOption, length_from=lambda p:p.ihl * 4 - 20)] # noqa: E501
def post_build(self, p, pay):
ihl = self.ihl
p += b"\0" * ((-len(p)) % 4) # pad IP options if needed
if ihl is None:
ihl = len(p) // 4
p = chb(((self.version & 0xf) << 4) | ihl & 0x0f) + p[1:]
if self.len is None:
tmp_len = len(p) + len(pay)
p = p[:2] + struct.pack("!H", tmp_len) + p[4:]
if self.chksum is None:
ck = checksum(p)
p = p[:10] + chb(ck >> 8) + chb(ck & 0xff) + p[12:]
return p + pay
def extract_padding(self, s):
tmp_len = self.len - (self.ihl << 2)
if tmp_len < 0:
return s, b""
return s[:tmp_len], s[tmp_len:]
def route(self):
dst = self.dst
if isinstance(dst, Gen):
dst = next(iter(dst))
if conf.route is None:
# unused import, only to initialize conf.route
import scapy.route # noqa: F401
return conf.route.route(dst)
def hashret(self):
if ((self.proto == socket.IPPROTO_ICMP) and
(isinstance(self.payload, ICMP)) and
(self.payload.type in [3, 4, 5, 11, 12])):
return self.payload.payload.hashret()
if not conf.checkIPinIP and self.proto in [4, 41]: # IP, IPv6
return self.payload.hashret()
if self.dst == "224.0.0.251": # mDNS
return struct.pack("B", self.proto) + self.payload.hashret()
if conf.checkIPsrc and conf.checkIPaddr:
return (strxor(inet_pton(socket.AF_INET, self.src),
inet_pton(socket.AF_INET, self.dst)) +
struct.pack("B", self.proto) + self.payload.hashret())
return struct.pack("B", self.proto) + self.payload.hashret()
def answers(self, other):
if not conf.checkIPinIP: # skip IP in IP and IPv6 in IP
if self.proto in [4, 41]:
return self.payload.answers(other)
if isinstance(other, IP) and other.proto in [4, 41]:
return self.answers(other.payload)
if conf.ipv6_enabled \
and isinstance(other, scapy.layers.inet6.IPv6) \
and other.nh in [4, 41]:
return self.answers(other.payload)
if not isinstance(other, IP):
return 0
if conf.checkIPaddr:
if other.dst == "224.0.0.251" and self.dst == "224.0.0.251": # mDNS # noqa: E501
return self.payload.answers(other.payload)
elif (self.dst != other.src):
return 0
if ((self.proto == socket.IPPROTO_ICMP) and
(isinstance(self.payload, ICMP)) and
(self.payload.type in [3, 4, 5, 11, 12])):
# ICMP error message
return self.payload.payload.answers(other)
else:
if ((conf.checkIPaddr and (self.src != other.dst)) or
(self.proto != other.proto)):
return 0
return self.payload.answers(other.payload)
def mysummary(self):
s = self.sprintf("%IP.src% > %IP.dst% %IP.proto%")
if self.frag:
s += " frag:%i" % self.frag
return s
def fragment(self, fragsize=1480):
"""Fragment IP datagrams"""
lastfragsz = fragsize
fragsize -= fragsize % 8
lst = []
fnb = 0
fl = self
while fl.underlayer is not None:
fnb += 1
fl = fl.underlayer
for p in fl:
s = raw(p[fnb].payload)
if len(s) <= lastfragsz:
lst.append(p)
continue
nb = (len(s) - lastfragsz + fragsize - 1) // fragsize + 1
for i in range(nb):
q = p.copy()
del(q[fnb].payload)
del(q[fnb].chksum)
del(q[fnb].len)
if i != nb - 1:
q[fnb].flags |= 1
fragend = (i + 1) * fragsize
else:
fragend = i * fragsize + lastfragsz
q[fnb].frag += i * fragsize // 8
r = conf.raw_layer(load=s[i * fragsize:fragend])
r.overload_fields = p[fnb].payload.overload_fields.copy()
q.add_payload(r)
lst.append(q)
return lst
def in4_chksum(proto, u, p):
"""
As Specified in RFC 2460 - 8.1 Upper-Layer Checksums
Performs IPv4 Upper Layer checksum computation. Provided parameters are:
- 'proto' : value of upper layer protocol
- 'u' : IP upper layer instance
- 'p' : the payload of the upper layer provided as a string
"""
if not isinstance(u, IP):
warning("No IP underlayer to compute checksum. Leaving null.")
return 0
if u.len is not None:
if u.ihl is None:
olen = sum(len(x) for x in u.options)
ihl = 5 + olen // 4 + (1 if olen % 4 else 0)
else:
ihl = u.ihl
ln = max(u.len - 4 * ihl, 0)
else:
ln = len(p)
# Filter out IPOption_LSRR and IPOption_SSRR
sr_options = [opt for opt in u.options if isinstance(opt, IPOption_LSRR) or
isinstance(opt, IPOption_SSRR)]
len_sr_options = len(sr_options)
if len_sr_options == 1 and len(sr_options[0].routers):
# The checksum must be computed using the final
# destination address
u.dst = sr_options[0].routers[-1]
elif len_sr_options > 1:
message = "Found %d Source Routing Options! "
message += "Falling back to IP.dst for checksum computation."
warning(message, len_sr_options)
psdhdr = struct.pack("!4s4sHH",
inet_pton(socket.AF_INET, u.src),
inet_pton(socket.AF_INET, u.dst),
proto,
ln)
return checksum(psdhdr + p)
class TCP(Packet):
name = "TCP"
fields_desc = [ShortEnumField("sport", 20, TCP_SERVICES),
ShortEnumField("dport", 80, TCP_SERVICES),
IntField("seq", 0),
IntField("ack", 0),
BitField("dataofs", None, 4),
BitField("reserved", 0, 3),
FlagsField("flags", 0x2, 9, "FSRPAUECN"),
ShortField("window", 8192),
XShortField("chksum", None),
ShortField("urgptr", 0),
TCPOptionsField("options", "")]
def post_build(self, p, pay):
p += pay
dataofs = self.dataofs
if dataofs is None:
opt_len = len(self.get_field("options").i2m(self, self.options))
dataofs = 5 + ((opt_len + 3) // 4)
dataofs = (dataofs << 4) | orb(p[12]) & 0x0f
p = p[:12] + chb(dataofs & 0xff) + p[13:]
if self.chksum is None:
if isinstance(self.underlayer, IP):
ck = in4_chksum(socket.IPPROTO_TCP, self.underlayer, p)
p = p[:16] + struct.pack("!H", ck) + p[18:]
elif conf.ipv6_enabled and isinstance(self.underlayer, scapy.layers.inet6.IPv6) or isinstance(self.underlayer, scapy.layers.inet6._IPv6ExtHdr): # noqa: E501
ck = scapy.layers.inet6.in6_chksum(socket.IPPROTO_TCP, self.underlayer, p) # noqa: E501
p = p[:16] + struct.pack("!H", ck) + p[18:]
else:
log_runtime.info(
"No IP underlayer to compute checksum. Leaving null."
)
return p
def hashret(self):
if conf.checkIPsrc:
return struct.pack("H", self.sport ^ self.dport) + self.payload.hashret() # noqa: E501
else:
return self.payload.hashret()
def answers(self, other):
if not isinstance(other, TCP):
return 0
# RST packets don't get answers
if other.flags.R:
return 0
# We do not support the four-way handshakes with the SYN+ACK
# answer split in two packets (one ACK and one SYN): in that
# case the ACK will be seen as an answer, but not the SYN.
if self.flags.S:
# SYN packets without ACK are not answers
if not self.flags.A:
return 0
# SYN+ACK packets answer SYN packets
if not other.flags.S:
return 0
if conf.checkIPsrc:
if not ((self.sport == other.dport) and
(self.dport == other.sport)):
return 0
# Do not check ack value for SYN packets without ACK
if not (other.flags.S and not other.flags.A) \
and abs(other.ack - self.seq) > 2:
return 0
# Do not check ack value for RST packets without ACK
if self.flags.R and not self.flags.A:
return 1
if abs(other.seq - self.ack) > 2 + len(other.payload):
return 0
return 1
def mysummary(self):
if isinstance(self.underlayer, IP):
return self.underlayer.sprintf("TCP %IP.src%:%TCP.sport% > %IP.dst%:%TCP.dport% %TCP.flags%") # noqa: E501
elif conf.ipv6_enabled and isinstance(self.underlayer, scapy.layers.inet6.IPv6): # noqa: E501
return self.underlayer.sprintf("TCP %IPv6.src%:%TCP.sport% > %IPv6.dst%:%TCP.dport% %TCP.flags%") # noqa: E501
else:
return self.sprintf("TCP %TCP.sport% > %TCP.dport% %TCP.flags%")
class UDP(Packet):
name = "UDP"
fields_desc = [ShortEnumField("sport", 53, UDP_SERVICES),
ShortEnumField("dport", 53, UDP_SERVICES),
ShortField("len", None),
XShortField("chksum", None), ]
def post_build(self, p, pay):
p += pay
tmp_len = self.len
if tmp_len is None:
tmp_len = len(p)
p = p[:4] + struct.pack("!H", tmp_len) + p[6:]
if self.chksum is None:
if isinstance(self.underlayer, IP):
ck = in4_chksum(socket.IPPROTO_UDP, self.underlayer, p)
# According to RFC768 if the result checksum is 0, it should be set to 0xFFFF # noqa: E501
if ck == 0:
ck = 0xFFFF
p = p[:6] + struct.pack("!H", ck) + p[8:]
elif isinstance(self.underlayer, scapy.layers.inet6.IPv6) or isinstance(self.underlayer, scapy.layers.inet6._IPv6ExtHdr): # noqa: E501
ck = scapy.layers.inet6.in6_chksum(socket.IPPROTO_UDP, self.underlayer, p) # noqa: E501
# According to RFC2460 if the result checksum is 0, it should be set to 0xFFFF # noqa: E501
if ck == 0:
ck = 0xFFFF
p = p[:6] + struct.pack("!H", ck) + p[8:]
else:
log_runtime.info(
"No IP underlayer to compute checksum. Leaving null."
)
return p
def extract_padding(self, s):
tmp_len = self.len - 8
return s[:tmp_len], s[tmp_len:]
def hashret(self):
return self.payload.hashret()
def answers(self, other):
if not isinstance(other, UDP):
return 0
if conf.checkIPsrc:
if self.dport != other.sport:
return 0
return self.payload.answers(other.payload)
def mysummary(self):
if isinstance(self.underlayer, IP):
return self.underlayer.sprintf("UDP %IP.src%:%UDP.sport% > %IP.dst%:%UDP.dport%") # noqa: E501
elif isinstance(self.underlayer, scapy.layers.inet6.IPv6):
return self.underlayer.sprintf("UDP %IPv6.src%:%UDP.sport% > %IPv6.dst%:%UDP.dport%") # noqa: E501
else:
return self.sprintf("UDP %UDP.sport% > %UDP.dport%")
icmptypes = {0: "echo-reply",
3: "dest-unreach",
4: "source-quench",
5: "redirect",
8: "echo-request",
9: "router-advertisement",
10: "router-solicitation",
11: "time-exceeded",
12: "parameter-problem",
13: "timestamp-request",
14: "timestamp-reply",
15: "information-request",
16: "information-response",
17: "address-mask-request",
18: "address-mask-reply",
30: "traceroute",
31: "datagram-conversion-error",
32: "mobile-host-redirect",
33: "ipv6-where-are-you",
34: "ipv6-i-am-here",
35: "mobile-registration-request",
36: "mobile-registration-reply",
37: "domain-name-request",
38: "domain-name-reply",
39: "skip",
40: "photuris"}
icmpcodes = {3: {0: "network-unreachable",
1: "host-unreachable",
2: "protocol-unreachable",
3: "port-unreachable",
4: "fragmentation-needed",
5: "source-route-failed",
6: "network-unknown",
7: "host-unknown",
9: "network-prohibited",
10: "host-prohibited",
11: "TOS-network-unreachable",
12: "TOS-host-unreachable",
13: "communication-prohibited",
14: "host-precedence-violation",
15: "precedence-cutoff", },
5: {0: "network-redirect",
1: "host-redirect",
2: "TOS-network-redirect",
3: "TOS-host-redirect", },
11: {0: "ttl-zero-during-transit",
1: "ttl-zero-during-reassembly", },
12: {0: "ip-header-bad",
1: "required-option-missing", },
40: {0: "bad-spi",
1: "authentication-failed",
2: "decompression-failed",
3: "decryption-failed",
4: "need-authentification",
5: "need-authorization", }, }
class ICMP(Packet):
name = "ICMP"
fields_desc = [ByteEnumField("type", 8, icmptypes),
MultiEnumField("code", 0, icmpcodes, depends_on=lambda pkt:pkt.type, fmt="B"), # noqa: E501
XShortField("chksum", None),
ConditionalField(XShortField("id", 0), lambda pkt:pkt.type in [0, 8, 13, 14, 15, 16, 17, 18]), # noqa: E501
ConditionalField(XShortField("seq", 0), lambda pkt:pkt.type in [0, 8, 13, 14, 15, 16, 17, 18]), # noqa: E501
ConditionalField(ICMPTimeStampField("ts_ori", None), lambda pkt:pkt.type in [13, 14]), # noqa: E501
ConditionalField(ICMPTimeStampField("ts_rx", None), lambda pkt:pkt.type in [13, 14]), # noqa: E501
ConditionalField(ICMPTimeStampField("ts_tx", None), lambda pkt:pkt.type in [13, 14]), # noqa: E501
ConditionalField(IPField("gw", "0.0.0.0"), lambda pkt:pkt.type == 5), # noqa: E501
ConditionalField(ByteField("ptr", 0), lambda pkt:pkt.type == 12), # noqa: E501
ConditionalField(ByteField("reserved", 0), lambda pkt:pkt.type in [3, 11]), # noqa: E501
ConditionalField(ByteField("length", 0), lambda pkt:pkt.type in [3, 11, 12]), # noqa: E501
ConditionalField(IPField("addr_mask", "0.0.0.0"), lambda pkt:pkt.type in [17, 18]), # noqa: E501
ConditionalField(ShortField("nexthopmtu", 0), lambda pkt:pkt.type == 3), # noqa: E501
MultipleTypeField(
[
(ShortField("unused", 0),
lambda pkt:pkt.type in [11, 12]),
(IntField("unused", 0),
lambda pkt:pkt.type not in [0, 3, 5, 8, 11, 12,
13, 14, 15, 16, 17,
18])
], StrFixedLenField("unused", "", length=0)),
]
def post_build(self, p, pay):
p += pay
if self.chksum is None:
ck = checksum(p)
p = p[:2] + chb(ck >> 8) + chb(ck & 0xff) + p[4:]
return p
def hashret(self):
if self.type in [0, 8, 13, 14, 15, 16, 17, 18, 33, 34, 35, 36, 37, 38]:
return struct.pack("HH", self.id, self.seq) + self.payload.hashret() # noqa: E501
return self.payload.hashret()
def answers(self, other):
if not isinstance(other, ICMP):
return 0
if ((other.type, self.type) in [(8, 0), (13, 14), (15, 16), (17, 18), (33, 34), (35, 36), (37, 38)] and # noqa: E501
self.id == other.id and
self.seq == other.seq):
return 1
return 0
def guess_payload_class(self, payload):
if self.type in [3, 4, 5, 11, 12]:
return IPerror
else:
return None
def mysummary(self):
if isinstance(self.underlayer, IP):
return self.underlayer.sprintf("ICMP %IP.src% > %IP.dst% %ICMP.type% %ICMP.code%") # noqa: E501
else:
return self.sprintf("ICMP %ICMP.type% %ICMP.code%")
class IPerror(IP):
name = "IP in ICMP"
def answers(self, other):
if not isinstance(other, IP):
return 0
# Check if IP addresses match
test_IPsrc = not conf.checkIPsrc or self.src == other.src
test_IPdst = self.dst == other.dst
# Check if IP ids match
test_IPid = not conf.checkIPID or self.id == other.id
test_IPid |= conf.checkIPID and self.id == socket.htons(other.id)
# Check if IP protocols match
test_IPproto = self.proto == other.proto
if not (test_IPsrc and test_IPdst and test_IPid and test_IPproto):
return 0
return self.payload.answers(other.payload)
def mysummary(self):
return Packet.mysummary(self)
class TCPerror(TCP):
name = "TCP in ICMP"
def answers(self, other):
if not isinstance(other, TCP):
return 0
if conf.checkIPsrc:
if not ((self.sport == other.sport) and
(self.dport == other.dport)):
return 0
if conf.check_TCPerror_seqack:
if self.seq is not None:
if self.seq != other.seq:
return 0
if self.ack is not None:
if self.ack != other.ack:
return 0
return 1
def mysummary(self):
return Packet.mysummary(self)
class UDPerror(UDP):
name = "UDP in ICMP"
def answers(self, other):
if not isinstance(other, UDP):
return 0
if conf.checkIPsrc:
if not ((self.sport == other.sport) and
(self.dport == other.dport)):
return 0
return 1
def mysummary(self):
return Packet.mysummary(self)