Link Layer Protocols

pcapkit.protocols.link is collection of all protocols in link layer, with detailed implementation and methods.

• ARP/InARP - (Inverse) Address Resolution Protocol
  • Data Structure
• Ethernet Protocol
  • Data Structure
• L2TP - Layer Two Tunnelling Protocol
  • Data Structure
• OSPF - Open Shortest Path First
  • Data Structure
    • Cryptographic Authentication Information
• RARP/DRARP - (Dynamic) Reverse Address Resolution Protocol
• VLAN - 802.1Q Customer VLAN Tag Type
  • Data Structure

Base Protocol

pcapkit.protocols.link.link contains Link, which is a base class for link layer protocols, e.g. ARP/InARP, Ethernet, L2TP, OSPF, RARP/DRARP and etc.

class pcapkit.protocols.link.link.Link(file=None, length=None, **kwargs)

Bases: pcapkit.protocols.protocol.Protocol

Abstract base class for link layer protocol family.

__layer__ = 'Link'

Layer of protocol.

__proto__: DefaultDict[int, Tuple[str, str]]

Protocol index mapping for decoding next layer, c.f. self._decode_next_layer & self._import_next_layer. The values should be a tuple representing the module name and class name.

Code	Module	Class
0x0806	pcapkit.protocols.link.arp	ARP
0x8035	pcapkit.protocols.link.rarp	RARP
0x8100	pcapkit.protocols.link.vlan	VLAN
0x0800	pcapkit.protocols.internet.ipv4	IPv4
0x86DD	pcapkit.protocols.internet.ipv6	IPv6
0x8137	pcapkit.protocols.internet.ipx	IPX

_import_next_layer(proto, length=None)

Import next layer extractor.

This method currently supports following protocols as registered in EtherType:

proto	Protocol
0x0806	ARP
0x8035	RARP
0x8100	VLAN
0x0800	IPv4
0x86DD	IPv6
0x8137	IPX

Parameters

• proto (int) – next layer protocol index

• length (int) – valid (non-padding) length

Returns

instance of next layer

Return type

pcapkit.protocols.protocol.Protocol

_read_protos(size)

Read next layer protocol type.

Parameters

size (int) – buffer size

Returns

next layer’s protocol enumeration

Return type

pcapkit.const.reg.ethertype.EtherType

property layer

Protocol layer.

Return type

Literal[‘Link’]