class SLPSrvTypeRqst(Packet):
name = "SLPSrvTypeRqst"
fields_desc = [
FieldLenField("prlist_len", None, length_of="prlist"),
BoundStrLenField("prlist", b"", length_from=lambda x: x.prlist_len),
FieldLenField("naming_auth_len", None, length_of="naming_auth"),
BoundStrLenField("naming_auth",
b"",
length_from=lambda x: x.naming_auth_len
if x.naming_auth_len < 0xffff else 0),
FieldLenField("scope_list_len", None, length_of="scope_list"),
BoundStrLenField("scope_list",
b"DEFAULT",
length_from=lambda x: x.scope_list_len),
]
class ISIS_PaddingTlv(ISIS_GenericTlv):
name = "ISIS Padding TLV"
fields_desc = [
ByteEnumField("type", 8, _isis_tlv_names),
FieldLenField("len", None, length_of="padding", fmt="B"),
BoundStrLenField("padding", "", length_from=lambda pkt: pkt.len)
]
class _ISIS_GenericTlv_Base(Packet):
fields_desc = [ByteField("type", 0),
FieldLenField("len", None, length_of="val", fmt="B"),
BoundStrLenField("val", "", length_from=lambda pkt: pkt.len)] # noqa: E501
def guess_payload_class(self, p):
return conf.padding_layer
class ISIS_DynamicHostnameTlv(ISIS_GenericTlv):
name = "ISIS Dynamic Hostname TLV"
fields_desc = [
ByteEnumField("type", 137, _isis_tlv_names),
FieldLenField("len", None, length_of="hostname", fmt="B"),
BoundStrLenField("hostname", "", length_from=lambda pkt: pkt.len)
] # noqa: E501
class SLPExtension(Packet):
name = "SLPExtension"
__slots__ = ["my_offset", "pkt_len"]
fields_desc = [
XShortField("ext_id", 0),
ThreeBytesField("next_ext_off", 0),
BoundStrLenField(
"data",
b"",
length_from=lambda pkt, *args: pkt._length_from(pkt, *args))
]
@classmethod
def _length_from(cls, x):
ext_end = x.next_ext_off if x.next_ext_off else x.pkt_len
r = max(0, ext_end - x.my_offset - 5)
#log.debug(f"Ext: my_len {r} next_off {x.next_ext_off} my_off {x.my_offset} total {x.pkt_len}")
if ext_end > x.pkt_len:
raise Scapy_Exception(
"%s: malformed packet, extension exceeds packet length" %
cls.__name__)
return r
# https://github.com/secdev/scapy/blob/cfe00d5c952e9048a40150390e0025b5ceff7228/scapy/layers/bluetooth.py#L485
def __init__(self, _pkt=None, offset=0, pkt_len=0, **kwargs):
self.my_offset = offset
self.pkt_len = pkt_len
Packet.__init__(self, _pkt, **kwargs)
def extract_padding(self, p):
return "", p
class ISIS_GenericSubTlv(Packet):
name = "ISIS Generic Sub-TLV"
fields_desc = [ByteField("type", 0),
FieldLenField("len", None, length_of="val", fmt="B"),
BoundStrLenField("val", "", length_from=lambda pkt: pkt.len)]
def guess_payload_class(self, p):
return conf.padding_layer
class SLPAuthBlock(Packet):
name = "SLPAuthBlock"
fields_desc = [
XShortField("block_structure_descriptor", 0),
ShortField("auth_block_len", 0),
IntField("timestamp", 0),
FieldLenField("slp_spi_len", None, length_of="slp_spi"),
BoundStrLenField("slp_spi", b"", length_from=lambda x: x.slp_spi_len),
BoundStrLenField(
"auth_block",
b"",
length_from=lambda x: x.auth_block_len - x.slp_spi_len - 8)
]
def extract_padding(self, p):
# log.debug("Auth >>>> ", p)
return "", p
class SLPAttrRqst(Packet):
name = "SLPAttrRqst"
fields_desc = [
FieldLenField("prlist_len", None, length_of="prlist"),
BoundStrLenField("prlist", b"", length_from=lambda x: x.prlist_len),
FieldLenField("url_len", None, length_of="url"),
BoundStrLenField("url", b"", length_from=lambda x: x.url_len),
FieldLenField("scope_list_len", None, length_of="scope_list"),
BoundStrLenField("scope_list",
b"DEFAULT",
length_from=lambda x: x.scope_list_len),
FieldLenField("tag_list_len", None, length_of="tag_list"),
BoundStrLenField("tag_list", b"",
length_from=lambda x: x.tag_list_len),
FieldLenField("slp_spi_len", None, length_of="slp_spi"),
BoundStrLenField("slp_spi", b"", length_from=lambda x: x.slp_spi_len),
]
class SLPSrvTypeRply(Packet):
name = "SLPSrvTypeRply"
fields_desc = [
ShortField("error_code", 0),
FieldLenField("srvtype_list_len", None, length_of="srvtype_list"),
BoundStrLenField("srvtype_list",
b"",
length_from=lambda x: x.srvtype_list_len)
]
class SLPSrvRqst(Packet):
name = "SLPSrvRqst"
fields_desc = [
FieldLenField("prlist_len", None, length_of="prlist"),
BoundStrLenField("prlist", b"", length_from=lambda x: x.prlist_len),
FieldLenField("service_type_len", None, length_of="service_type"),
BoundStrLenField("service_type",
b"",
length_from=lambda x: x.service_type_len),
FieldLenField("scope_list_len", None, length_of="scope_list"),
BoundStrLenField("scope_list",
b"DEFAULT",
length_from=lambda x: x.scope_list_len),
FieldLenField("predicate_len", None, length_of="predicate"),
BoundStrLenField("predicate",
b"",
length_from=lambda x: x.predicate_len),
FieldLenField("slp_spi_len", None, length_of="slp_spi"),
BoundStrLenField("slp_spi", b"", length_from=lambda x: x.slp_spi_len),
]
class _PIMGenericTlvBase(Packet):
fields_desc = [
ByteField("type", 0),
FieldLenField("length", None, length_of="value", fmt="B"),
BoundStrLenField("value", "", length_from=lambda pkt: pkt.length)
]
def guess_payload_class(self, p):
return conf.padding_layer
def extract_padding(self, s):
return "", s
class SLPURLEntry(Packet):
name = "SLPURLEntry"
fields_desc = [
ByteField("reserved", 0),
ShortField("lifetime", 0),
FieldLenField("url_len", None, length_of="url"),
BoundStrLenField("url", b"", length_from=lambda x: x.url_len)
]
def extract_padding(self, p):
# log.debug("URL >>>> ", p)
return "", p
class SLPAttrRply(Packet):
name = "SLPAttrRply"
fields_desc = [
ShortField("error_code", 0),
FieldLenField("attr_list_len", None, length_of="attr_list"),
BoundStrLenField("attr_list",
b"",
length_from=lambda x: x.attr_list_len),
FieldLenField("auth_blocks_cnt", None, fmt="b",
count_of="auth_blocks"),
PacketListField("auth_blocks", [],
SLPAuthBlock,
count_from=lambda pkt: pkt.auth_blocks_cnt),
]
class ISIS_AuthenticationTlv(ISIS_GenericTlv):
name = "ISIS Authentication TLV"
fields_desc = [
ByteEnumField("type", 10, _isis_tlv_names),
FieldLenField("len",
None,
length_of="password",
adjust=lambda pkt, x: x + 1,
fmt="B"), # noqa: E501
ByteEnumField("authtype", 1, {
1: "Plain",
17: "HMAC-MD5"
}),
BoundStrLenField("password",
"",
maxlen=254,
length_from=lambda pkt: pkt.len - 1)
] # noqa: E501
class SLPv2(Packet):
name = "SLPv2"
__slots__ = ["ext_len"]
fields_desc = [
ByteField("version", 2),
ByteEnumField("function", 1, _function_names),
ThreeBytesField("length", None),
FlagsField("flags", 0, 3, "OFR"),
BitField("reserved", 0, 13),
# TODO: handle sending extententions
# http://www.networksorcery.com/enp/rfc/rfc2608.txt Section 9.1
ThreeBytesField("next_ext_off", 0),
XShortField("xid", RandShort()),
FieldLenField("lang_tag_len", None, length_of="lang_tag"),
BoundStrLenField("lang_tag",
b"en",
length_from=lambda x: x.lang_tag_len),
ConditionalField(
PacketListField(
"extensions", [],
SLPExtension,
next_cls_cb=lambda pkt, *args: pkt._next_cls_cb(pkt, *args)),
# next_cls_cb=lambda pkt, lst, cur, remain:
# SLPExtension if pkt.value_follows == 1 and
# (len(lst) == 0 or cur.value_follows == 1) and
# len(remain) > 4 else None),
lambda pkt: pkt.next_ext_off > 0)
]
@classmethod
def _next_cls_cb(cls, pkt, lst, cur, remain):
next_off = pkt.next_ext_off if cur is None else cur.next_ext_off
if next_off == 0:
return None
if next_off + 5 > pkt.length:
raise Scapy_Exception(
"%s: malformed packet, extension header exceeds packet length"
% cls.__name__)
if cur is None and next_off < 15:
raise Scapy_Exception(
"%s: malformed packet, extension points to header" %
cls.__name__)
if cur is not None and cur.next_ext_off <= cur.my_offset + 5:
raise Scapy_Exception("%s: malformed packet, extension overlap" %
cls.__name__)
return lambda *args: SLPExtension(
*args, offset=next_off, pkt_len=pkt.length)
# for fn, cls in _function_classes.items():
# def get_conditional_field(fn, cls):
# return ConditionalField(
# PacketField("slp_body", cls(), cls),
# lambda pkt: pkt.function == fn
# )
# fields_desc.append(get_conditional_field(fn, cls))
def guess_payload_class(self, payload):
ret = _function_classes.get(self.function)
#log.debug("Guess next payload", ret)
return ret
# def extract_padding(self, p):
# log.debug(p)
# return "", p
def pre_dissect(self, s):
# move extensions
# log.debug(s)
length = struct.unpack("!I", b"\x00" + s[2:5])[0]
next_ext_offset = struct.unpack("!I", b"\x00" + s[7:10])[0]
lang_tag_len = struct.unpack("!H", s[12:14])[0]
header_len = 14 + lang_tag_len
#log.debug("Len ", length, len(s), next_ext_offset, header_len)
self.ext_len = 0
if length > len(s):
raise Exception(
"%s: malformed packet, shorter than header length" %
cls.__name__)
if next_ext_offset == 0:
return s
self.ext_len = len(s) - next_ext_offset
#log.debug("ext_len", self.ext_len)
# Dropping whats behind length from header,swap payload and extensions
ret = s[:header_len] + s[next_ext_offset:length] + \
s[header_len:next_ext_offset] # [:4] + s[-3:] + s[4:-3]
# log.debug(s)
# log.debug(ret)
return ret
def post_build(self, p, pay):
if len(self.extensions) > 0:
raise NotImplementedError("Sending extensions not implemented yet")
if self.length is None:
tmp_len = len(pay) + len(p) # + 1 # +len(p)
#log.debug(p, tmp_len)
p = p[:2] + struct.pack("!I", tmp_len)[1:4] + p[5:]
return p + pay
