Abstract PDU¶

class PDU¶

Bases: object

Abstract Protocol Data Unit

To build a PDU from a buffer:

>>> buf = [
...     170, 187, 204, 221, 238, 255, 138, 139, 140, 141, 142, 143, 208, 171,
...     00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00,
...     00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00,
...     00, 00, 00, 00, 00, 00, 00, 00, 00, 00
... ]
>>> buf = "".join([chr(i) for i in buf])
>>> pdu = EthernetII.from_buffer(buf)

PDU objects supports equality:

>>> pdu1 = EthernetII.from_buffer(buf1)
>>> pdu2 = EthernetII.from_buffer(buf2)
>>> if pdu1 == pdu2:
...     print("Equals")

PDU objects can be copied:

>>> import copy
>>> pdu1 = EthernetII.from_buffer(buf1)
>>> pdu2 = pdu.copy()
>>> pdu3 = copy.copy(pdu1)

PDU objects can be pickled:

>>> import pickle
>>> pdu = EthernetII.from_buffer(buf1)
>>> d = pickle.dumps(pdu)

PDU can be built by concatenation:

>>> pdu = EthernetII() / IP()

PDU is abstract:

>>> from cycapture.libtins import PDU
>>> pdu = PDU()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "cycapture/libtins/pdu_pyx.pxi", line 190, in cycapture.libtins._tins.PDU.__cinit__
    raise NotImplementedError
NotImplementedError

copy()¶

Copy (deep-copy) the PDU

Returns:	PDU (`PDU`) -- the cloned PDU

copy_inner_pdu()¶

Returns a copy of the inner PDU, or None if self has no child

Returns:	PDU (`PDU`) -- A copy of the inner PDU

find_pdu()¶

Search the successive inner PDUs

Parameters:	obj (PDU class)
Returns:	PDU (`PDU`) -- a copy of the matching inner PDU
Raises:	`PDUNotFound` (`PDUNotFound`) -- if no marching PDU is found

find_pdu_by_type(int t)¶

Search the successive inner PDUs, by PDU type

Parameters:	t (int) -- the type of the PDU that you're looking for
Returns:	PDU (`PDU`) -- a copy of the matching inner PDU
Raises:	`PDUNotFound` (`PDUNotFound`) -- if no marching PDU is found

from_buffer(buf)¶

Factory classmethod, to make a concrete PDU from a buffer

Parameters:	buf (bytes or bytearray or memoryview or cython memoryview)
Returns:	PDU (`PDU`) -- The new PDU
Raises:	`MalformedPacket` (`MalformedPacket`) -- if the given buffer can not be interpreted as an instance of the concrete PDU

Note

Class method

get_pdu_type()¶

Returns:	int -- The PDU type

matches_response(buf)¶

Checks if the given buffer can be a valid response to the current PDU

Parameters:	buf (bytes or bytearray or memoryview or cython memoryview)
Returns:	bool -- `True` if buf is a response to the PDU

ref_inner_pdu()¶

Returns a reference to the inner PDU, or None if self has no child

Returns:	PDU (`PDU`) -- A reference of the inner PDU

reference()¶

Returns a reference of the current PDU

Returns:	PDU (`PDU`) -- the reference

rfind_pdu(obj)¶

Search the successive inner PDUs

Parameters:	obj (PDU class)
Returns:	PDU (`PDU`) -- a reference of the matching inner PDU
Raises:	`PDUNotFound` (`PDUNotFound`) -- if no marching PDU is found

rfind_pdu_by_datalink_type(int t)¶

Search the successive inner PDUs, by datalink type

Parameters:	t (int) -- the datalink type of the PDU that you're looking for
Returns:	PDU (`PDU`) -- a reference of the matching inner PDU
Raises:	`PDUNotFound` (`PDUNotFound`) -- if no marching PDU is found

rfind_pdu_by_type(int t)¶

Search the successive inner PDUs, by PDU type

Parameters:	t (int) -- the type of the PDU that you're looking for
Returns:	PDU (`PDU`) -- a reference of the matching inner PDU
Raises:	`PDUNotFound` (`PDUNotFound`) -- if no marching PDU is found

serialize()¶

Serialize the PDU

Returns:	bytes -- the PDU as bytes

set_inner_pdu(obj)¶

Replace the inner PDU with obj.

Note

obj is cloned before being set as the inner PDU.

Parameters:	obj (`PDU`) -- the replacement PDU

header_size¶: Returns the PDU's header size (read-only property)

size¶: Returns the PDU's size (read-only property)

trailer_size¶: Returns the PDU's trailer size (read-only property)

Quick search

Abstract PDU¶