def _fle_message_from_packet(self, packet):
src, dst = self._parse_packet_src_dst(packet)
data = get_ip_packet(packet.load).data.data
message = FLE.Message.from_payload(data, '%s:%d' % (src[0], src[1]),
'%s:%d' % (dst[0], dst[1]),
time.time())
return message
def _parse_packet_src_dst(self, packet):
assert isinstance(packet, Packet)
ip_p = get_ip_packet(packet.load)
src = (get_ip(ip_p, ip_p.src), ip_p.data.sport)
dst = (get_ip(ip_p, ip_p.dst), ip_p.data.dport)
ret = (src, dst)
return ret
def _parse_packet_src_dst(self, packet): assert isinstance(packet, Packet) ip_p = get_ip_packet(packet.load) src = (get_ip(ip_p, ip_p.src), ip_p.data.sport) dst = (get_ip(ip_p, ip_p.dst), ip_p.data.dport) ret = (src, dst) return ret
def _fle_message_from_packet(self, packet):
src, dst = self._parse_packet_src_dst(packet)
data = get_ip_packet(packet.load).data.data
message = FLE.Message.from_payload(data,
'%s:%d' % (src[0], src[1]),
'%s:%d' % (dst[0], dst[1]),
time.time())
return message
def _is_packet_fle_initial(self, packet):
data = get_ip_packet(packet.load).data.data
proto, offset = read_long(data, 0)
if proto != FLE.Initial.PROTO_VER: return False
server_id, offset = read_long(data, offset)
if server_id < 0: return False
election_addr, offset = read_string(data, offset)
if election_addr.count(":") != 1: return False
expected_len = 8 + 8 + 4 + len(election_addr)
if len(data) != expected_len: return False
return True
def _is_packet_fle_initial(self, packet):
data = get_ip_packet(packet.load).data.data
proto, offset = read_long(data, 0)
if proto != FLE.Initial.PROTO_VER: return False
server_id, offset = read_long(data, offset)
if server_id < 0: return False
election_addr, offset = read_string(data, offset)
if election_addr.count(":") != 1: return False
expected_len = 8 + 8 + 4 + len(election_addr)
if len(data) != expected_len: return False
return True
def _message_from_packet(self, packet):
"""
:returns: Returns an instance of Message
:raises:
:exc:`BadPacket` if the packet is of an unknown type
:exc:`DeserializationError` if deserialization failed
:exc:`struct.error` if deserialization failed
"""
ip_p = get_ip_packet(packet.load, 0, self._port)
if ip_p.data.sport != self._port and ip_p.data.dport != self._port:
raise BadPacket("Wrong port")
return self._msg_cls.from_payload(
ip_p.data.data,
intern("%s:%s" % (get_ip(ip_p, ip_p.src), ip_p.data.sport)),
intern("%s:%s" % (get_ip(ip_p, ip_p.dst), ip_p.data.dport)),
packet.time)
def _message_from_packet(self, packet):
"""
:returns: Returns an instance of Message
:raises:
:exc:`BadPacket` if the packet is of an unknown type
:exc:`DeserializationError` if deserialization failed
:exc:`struct.error` if deserialization failed
"""
ip_p = get_ip_packet(packet.load, 0, self._port)
if ip_p.data.sport != self._port and ip_p.data.dport != self._port:
raise BadPacket("Wrong port")
return self._msg_cls.from_payload(
ip_p.data.data,
intern("%s:%s" % (get_ip(ip_p, ip_p.src), ip_p.data.sport)),
intern("%s:%s" % (get_ip(ip_p, ip_p.dst), ip_p.data.dport)),
packet.time
)
def _check_packet(self, packet):
"""
check tcp seq duplicates
NOTE: TX/RX duplicate happens on loopback interfaces
:param packet:
:return: None
"""
src, dst = self._parse_packet_src_dst(packet)
tcp = get_ip_packet(packet.load).data
if tcp.flags & dpkt.tcp.TH_RST:
if (src, dst) in self._last_tcp_seq:
del self._last_tcp_seq[(src, dst)]
else:
if not tcp.data: raise BadPacket("no payload")
if (src, dst) in self._last_tcp_seq:
last_seq = self._last_tcp_seq[(src, dst)]
if tcp.seq <= last_seq:
# this exception eliminates dups
raise BadPacket("This sequence(%d<=%d) seen before" % (tcp.seq, last_seq))
self._last_tcp_seq[(src, dst)] = tcp.seq
def _check_packet(self, packet):
"""
check tcp seq duplicates
NOTE: TX/RX duplicate happens on loopback interfaces
:param packet:
:return: None
"""
src, dst = self._parse_packet_src_dst(packet)
tcp = get_ip_packet(packet.load).data
if tcp.flags & dpkt.tcp.TH_RST:
if (src, dst) in self._last_tcp_seq:
del self._last_tcp_seq[(src, dst)]
else:
if not tcp.data: raise BadPacket("no payload")
if (src, dst) in self._last_tcp_seq:
last_seq = self._last_tcp_seq[(src, dst)]
if tcp.seq <= last_seq:
# this exception eliminates dups
raise BadPacket("This sequence(%d<=%d) seen before" %
(tcp.seq, last_seq))
self._last_tcp_seq[(src, dst)] = tcp.seq
