Base Protocol¶

pcapkit.protocols.application.application contains only Application, which is a base class for application layer protocols, eg. HTTP/1.*, HTTP/2 and etc.

Changed in version 1.5.0: _decode_next_layer() and _import_next_layer() accept the -1 sentinel, so an application layer protocol can carry the rest of its packet undissected as its payload; every call raised UnsupportedCall (#719).

class pcapkit.protocols.application.application.Application(file=None, length=None, **kwargs)[source]¶

Bases: ProtocolBase[_PT, _ST], Generic[_PT, _ST]

Abstract base class for application layer protocol family.

An application layer protocol has no further protocol layer above it, so _decode_next_layer() and _import_next_layer() refuse to dispatch on a protocol number. What they do permit is the -1 sentinel, which asks for the rest of the packet undissected and resolves to Raw – trailing bytes are not a further protocol layer – or to NoPayload when nothing remains.

property layer: Literal['Application']¶: Protocol layer.

_decode_next_layer(dict_, proto=None, length=None, *, packet=None)[source]¶

Decode next layer protocol.

Parameters:

dict_ (TypeVar(_PT, bound= Data)) – info buffer
proto (int | None) – next layer protocol index; only the -1 sentinel (the rest, undissected) is accepted
length (int | None) – valid (non-padding) length
packet (dict[str, Any] | None) – packet info (passed from self.unpack)

Return type:

TypeVar(_PT, bound= Data)

Returns:

Current protocol with the undissected remainder as payload.

Raises:

UnsupportedCall – proto is anything but -1, i.e. a real protocol dispatch, which this protocol doesn’t support.

_import_next_layer(proto, length=None, *, packet=None)[source]¶

Import next layer extractor.

Parameters:

proto (int) – next layer protocol index; only the -1 sentinel (the rest, undissected) is accepted
length (int | None) – valid (non-padding) length
packet (dict[str, Any] | None) – packet info (passed from self.unpack)

Return type:

ProtocolBase

Returns:

Instance of Raw, or of NoPayload when nothing remains.

Raises:

UnsupportedCall – proto is anything but -1, i.e. a real protocol dispatch, which this protocol doesn’t support.

__layer__: Literal['Application']¶: Layer of protocol.

__post_init__(file=None, length=None, **kwargs)[source]¶

Post initialisation hook.

Overloads:

self, file (IO[bytes] | bytes), length (Optional[int]), kwargs (Any) → None
self, kwargs (Any) → None

Parameters:

file (IO[bytes] | bytes | None) – Source packet stream.
length (int | None) – Length of packet data.
**kwargs (Any) – Arbitrary keyword arguments.