OSPF - Open Shortest Path First¶

pcapkit.protocols.link.ospf contains OSPF only, which implements extractor for Open Shortest Path First (OSPF) [*], whose structure is described as below:

Octets	Bits	Name	Description
0	0	`ospf.version`	Version Number
0	0	`ospf.type`	Type
0	1	`ospf.len`	Packet Length (header included)
0	2	`ospf.router_id`	Router ID
0	4	`ospf.area_id`	Area ID
0	6	`ospf.chksum`	Checksum
0	7	`ospf.autype`	Authentication Type
1	8	`ospf.auth`	Authentication

class pcapkit.protocols.link.ospf.OSPF(file=None, length=None, **kwargs)[source]¶

Bases: Link[OSPF, OSPF]

This class implements Open Shortest Path First.

property name: str¶: Name of current protocol.

property alias: str¶: Acronym of current protocol.

property length: Literal[24]¶: Header length of current protocol.

property type: Packet¶: OSPF packet type.

read(length=None, **kwargs)[source]¶

Read Open Shortest Path First.

Structure of OSPF header [RFC 2328]:

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Version #   |     Type      |         Packet length         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                          Router ID                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                           Area ID                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Checksum            |             AuType            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                       Authentication                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                       Authentication                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Parameters:

length (Optional[int]) – Length of packet data.
**kwargs (Any) – Arbitrary keyword arguments.

Return type:

OSPF

Returns:

Parsed packet data.

make(version=2, type=<Packet.Hello: 1>, type_default=None, type_namespace=None, type_reversed=False, router_id='0.0.0.0', area_id='0.0.0.0', checksum=b'\\x00\\x00', auth_type=<Authentication.No_Authentication: 0>, auth_type_default=None, auth_type_namespace=None, auth_type_reversed=False, auth_data=b'\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00', payload=b'', **kwargs)[source]¶

Make (construct) packet data.

Parameters:

version (int) – OSPF version number.
type (Packet | IntEnum | IntEnum | str | int) – OSPF packet type.
type_default (Optional[int]) – Default value for type if not specified.
type_namespace (Union[dict[str, int], dict[int, str], Type[IntEnum], Type[IntEnum], None]) – Namespace for type.
type_reversed (bool) – Reverse namespace for type.
router_id (IPv4Address | str | bytes | bytearray) – Router ID.
area_id (IPv4Address | str | bytes | bytearray) – Area ID.
checksum (bytes) – Checksum.
auth_type (Authentication | IntEnum | IntEnum | str | int) – Authentication type.
auth_type_default (Optional[int]) – Default value for auth_type if not specified.
auth_type_namespace (Union[dict[str, int], dict[int, str], Type[IntEnum], Type[IntEnum], None]) – Namespace for auth_type.
auth_type_reversed (bool) – Reverse namespace for auth_type.
auth_data (bytes | CrytographicAuthentication | CrytographicAuthentication) – Authentication data.
payload (bytes | ProtocolBase | Schema) – Payload data.
**kwargs (Any) – Arbitrary keyword arguments.

Return type:

OSPF

Returns:

Constructed packet data.

classmethod _make_data(data)[source]¶

Create key-value pairs from data for protocol construction.

Parameters:: data (OSPF) – protocol data
Return type:: dict[str, Any]
Returns:: Key-value pairs for protocol construction.

_read_encrypt_auth(schema)[source]¶

Read Authentication field when Cryptographic Authentication is employed, i.e. autype is 2.

Structure of Cryptographic Authentication [RFC 2328]:

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|              0                |    Key ID     | Auth Data Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                 Cryptographic sequence number                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Parameters:: schema (CrytographicAuthentication) – parsed authentication data
Return type:: CrytographicAuthentication
Returns:: Parsed packet data.

_make_encrypt_auth(auth_data)[source]¶

Make Authentication field when Cryptographic Authentication is employed.

Parameters:

auth_type – Authentication type.
auth_data (bytes | CrytographicAuthentication | CrytographicAuthentication) – Authentication data.

Return type:

bytes | CrytographicAuthentication

Returns:

Authentication bytes.

classmethod __index__()[source]¶

Numeral registry index of the protocol.

Raises:: UnsupportedCall – This protocol has no registry entry.
Return type:: NoReturn

Header Schemas¶

class pcapkit.protocols.schema.link.ospf.OSPF(dict_=None, **kwargs)[source]¶

Bases: Schema

Header schema for OSPF packet.

version: int = <UInt8Field version>¶: Version.

type: Enum_Packet = <EnumField type>¶: Type.

length: int = <UInt16Field length>¶: Length.

router_id: IPv4Address = <IPv4AddressField router_id>¶: Router ID.

area_id: IPv4Address = <IPv4AddressField area_id>¶: Area ID.

checksum: bytes = <BytesField checksum>¶: Checksum.

auth_type: Enum_Authentication = <EnumField auth_type>¶: Authentication type.

auth_data: bytes | CrytographicAuthentication = <SwitchField auth_data>¶: Authentication data.

payload: bytes = <PayloadField payload>¶: Payload.

class pcapkit.protocols.schema.link.ospf.CrytographicAuthentication(dict_=None, **kwargs)[source]¶

Bases: Schema

Header schema for OSPF cryptographic authentication.

reserved: bytes = <PaddingField reserved>¶: Reserved bytes.

key_id: int = <UInt8Field key_id>¶: Key ID.

len: int = <UInt8Field len>¶: Length.

seq: int = <UInt32Field seq>¶: Sequence number.

Auxiliary Functions¶

pcapkit.protocols.schema.link.ospf.ospf_auth_data_selector(pkt)[source]¶

Selector function for OSPF.auth_data field.

Parameters:

pkt (dict[str, Any]) – Packet data.

Return type:

FieldBase

Returns:

If OSPF.auth_type is 2, a SchemaField wrapped CrytographicAuthentication instance.
Otherwise, a BytesField instance.

Data Models¶

class pcapkit.protocols.data.link.ospf.OSPF(*args: VT, **kwargs: VT)[source]¶

Bases: Protocol

Data model for OSPF packet.

version: int¶: Version number.

type: Packet¶: Type.

len: int¶: Packet length (header included).

router_id: IPv4Address¶: Router ID.

area_id: IPv4Address¶: Area ID.

chksum: bytes¶: Checksum.

autype: Authentication¶: Authentication type.

auth: bytes | CrytographicAuthentication¶: Authentication.

class pcapkit.protocols.data.link.ospf.CrytographicAuthentication(*args: VT, **kwargs: VT)[source]¶

Bases: Data

Data model for OSPF crytographic authentication.

key_id: int¶: Key ID.

len: int¶: Authentication data length.

seq: int¶: Cryptographic sequence number.

Footnotes