CFDP Package

Package Contents

The CFDP module contains the low level components to create the CFDP packets as specfied in the standard. It also contains basic enumerations and abstractions which were considered useful and generic enough to be included. These abstractions can be used as a foundation to build more complex classes and handlers to perform full CFDP end-to-end transfers.

These components can not be found in this library, but you can find a reference implementation of high level handlers in the tmtccmd library.

You can find a usage example including multiple packet data units used to perform a full unacknowledged file transfer on the example page.

class spacepackets.cfdp.CfdpLv(value: bytes | bytearray)

Bases: object

This class encapsulates CFDP Length-Value (LV) fields.

Raises:: ValueError – If value is invalid and serilization is enabled or if length of bytearray is too large.

classmethod from_path(path: Path) → CfdpLv

classmethod from_str(string: str) → CfdpLv

pack() → bytearray

property packet_len: int: Returns length of full LV packet

classmethod unpack(raw_bytes: bytes | bytearray) → CfdpLv

Parses LV field at the start of the given bytearray

Raises:: ValueError – Invalid length found

class spacepackets.cfdp.CfdpTlv(tlv_type: TlvType, value: bytes | bytearray)

Bases: AbstractTlvBase

Encapsulates the CFDP Type-Length-Value (TLV) format. For more information, refer to CCSDS 727.0-B-5 p.77

Constructor for TLV field.

Raises:: ValueError – Length invalid or value length not equal to specified length.

MINIMAL_LEN = 2

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

classmethod unpack(data: bytes | bytearray) → CfdpTlv

Parses LV field at the start of the given bytearray

Parameters:

data

Raises:

BytesTooShortError – Length of raw data too short.
ValueError – Invalid format of the raw bytearray or type field invalid

Returns:

property value: bytes

class spacepackets.cfdp.ChecksumType(value)

Bases: IntEnum

An enumeration.

CRC_32 = 3

CRC_32C = 2

CRC_32_PROXIMITY_1 = 1

MODULAR = 0

NULL_CHECKSUM = 15

class spacepackets.cfdp.ConditionCode(value)

Bases: IntEnum

An enumeration.

CANCEL_REQUEST_RECEIVED = 15

CHECK_LIMIT_REACHED = 10

FILESTORE_REJECTION = 4

FILE_CHECKSUM_FAILURE = 5

FILE_SIZE_ERROR = 6

INACTIVITY_DETECTED = 8

INVALID_TRANSMISSION_MODE = 3

KEEP_ALIVE_LIMIT_REACHED = 2

NAK_LIMIT_REACHED = 7

NO_CONDITION_FIELD = -1

NO_ERROR = 0

POSITIVE_ACK_LIMIT_REACHED = 1

SUSPEND_REQUEST_RECEIVED = 14

UNSUPPORTED_CHECKSUM_TYPE = 11

class spacepackets.cfdp.CrcFlag(value)

Bases: IntEnum

An enumeration.

NO_CRC = 0

WITH_CRC = 1

class spacepackets.cfdp.DeliveryCode(value)

Bases: IntEnum

An enumeration.

DATA_COMPLETE = 0

DATA_INCOMPLETE = 1

class spacepackets.cfdp.Direction(value)

Bases: IntEnum

This is used for PDU forwarding

TOWARDS_RECEIVER = 0

TOWARDS_SENDER = 1

class spacepackets.cfdp.DirectiveType(value)

Bases: IntEnum

An enumeration.

ACK_PDU = 6

EOF_PDU = 4

FINISHED_PDU = 5

KEEP_ALIVE_PDU = 12

METADATA_PDU = 7

NAK_PDU = 8

NONE = 10

PROMPT_PDU = 9

class spacepackets.cfdp.EntityIdTlv(entity_id: bytes)

Bases: AbstractTlvBase

This helper class has a __eq__() implementation which only compares the numerical value of the entity IDs

TLV_TYPE = 6

classmethod from_tlv(cfdp_tlv: CfdpTlv) → EntityIdTlv

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

classmethod unpack(data: bytes | bytearray) → EntityIdTlv

property value: bytes

class spacepackets.cfdp.FaultHandlerCode(value)

Bases: IntEnum

An enumeration.

ABANDON_TRANSACTION = 4

IGNORE_ERROR = 3

NOTICE_OF_CANCELLATION = 1

NOTICE_OF_SUSPENSION = 2

class spacepackets.cfdp.FaultHandlerOverrideTlv(condition_code: ConditionCode, handler_code: FaultHandlerCode)

Bases: AbstractTlvBase

TLV_TYPE = 4

classmethod from_tlv(cfdp_tlv: CfdpTlv) → FaultHandlerOverrideTlv

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

classmethod unpack(data: bytes) → FaultHandlerOverrideTlv

property value: bytes

class spacepackets.cfdp.FileStatus(value)

Bases: IntEnum

An enumeration.

DISCARDED_DELIBERATELY = 0

DISCARDED_FILESTORE_REJECTION = 1

FILE_RETAINED = 2

FILE_STATUS_UNREPORTED = 3

class spacepackets.cfdp.FileStoreRequestTlv(action_code: FilestoreActionCode, first_file_name: str, second_file_name: str = '')

Bases: FileStoreRequestBase, AbstractTlvBase

TLV_TYPE = 0

classmethod from_tlv(cfdp_tlv: CfdpTlv) → FileStoreRequestTlv

generate_tlv() → None

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

classmethod unpack(data: bytes) → FileStoreRequestTlv

property value: bytes

class spacepackets.cfdp.FileStoreResponseTlv(action_code: FilestoreActionCode, status_code: FilestoreResponseStatusCode, first_file_name: str, second_file_name: str = '', filestore_msg: None | CfdpLv = None)

Bases: FileStoreRequestBase, AbstractTlvBase

TLV_TYPE = 1

classmethod from_tlv(cfdp_tlv: CfdpTlv) → FileStoreResponseTlv

generate_tlv() → None

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

classmethod unpack(data: bytes | bytearray) → FileStoreResponseTlv

property value: bytes

class spacepackets.cfdp.FilestoreActionCode(value)

Bases: IntEnum

All filestore action codes as specified in CCSDS 727.0-B-5 p.86 SNP: Second name present, SNN: Second name not present

APPEND_FILE_SNP = 3

CREATE_DIR_SNN = 5

CREATE_FILE_SNM = 0

DELETE_FILE_SNN = 1

DENY_DIR_SNN = 8

DENY_FILE_SMM = 7

REMOVE_DIR_SNN = 6

RENAME_FILE_SNP = 2

REPLACE_FILE_SNP = 4

class spacepackets.cfdp.FilestoreResponseStatusCode(value)

Bases: IntEnum

File store response status codes. First four bits are the action code, last four bits the status code

APPEND_FILE_NAME_ONE_NOT_EXISTS = 49

APPEND_FILE_NAME_TWO_NOT_EXISTS = 50

APPEND_FROM_DATA_FILE_NOT_EXISTS = 2

APPEND_NOT_ALLOWED = 51

APPEND_NOT_PERFORMED = 63

APPEND_SUCCESS = 48

CREATE_DIR_CAN_NOT_BE_CREATED = 81

CREATE_DIR_NOT_PERFORMED = 95

CREATE_DIR_SUCCESS = 80

CREATE_NOT_ALLOWED = 1

CREATE_NOT_PERFORMED = 15

CREATE_SUCCESS = 0

DELETE_FILE_DOES_NOT_EXIST = 17

DELETE_NOT_ALLOWED = 31

DELETE_SUCCESS = 16

DENY_DIR_DEL_NOT_ALLOWED = 130

DENY_DIR_DEL_NOT_PERFORMED = 143

DENY_DIR_DEL_SUCCESS = 128

DENY_FILE_DEL_NOT_ALLOWED = 114

DENY_FILE_DEL_NOT_PERFORMED = 127

DENY_FILE_DEL_SUCCESS = 112

INVALID = -1

NOT_PERFORMED = 15

REMOVE_DIR_DOES_NOT_EXIST = 97

REMOVE_DIR_NOT_ALLOWED = 98

REMOVE_DIR_NOT_PERFORMED = 111

REMOVE_DIR_SUCCESS = 96

RENAME_NEW_FILE_DOES_EXIST = 34

RENAME_NOT_ALLOWED = 35

RENAME_NOT_PERFORMED = 47

RENAME_OLD_FILE_DOES_NOT_EXIST = 33

RENAME_SUCCESS = 32

REPLACE_FILE_NAME_ONE_TO_BE_REPLACED_DOES_NOT_EXIST = 65

REPLACE_FILE_NAME_TWO_REPLACE_SOURCE_NOT_EXIST = 66

REPLACE_NOT_ALLOWED = 67

REPLACE_NOT_PERFORMED = 79

REPLACE_SUCCESS = 64

SUCCESS = 0

class spacepackets.cfdp.FinishedParams(condition_code: 'ConditionCode', delivery_code: 'DeliveryCode', file_status: 'FileStatus', file_store_responses: 'list[FileStoreResponseTlv]' = <factory>, fault_location: 'EntityIdTlv | None' = None)

Bases: object

condition_code: ConditionCode

delivery_code: DeliveryCode

classmethod empty() → FinishedParams

fault_location: EntityIdTlv | None = None

file_status: FileStatus

file_store_responses: list[FileStoreResponseTlv]

classmethod success_params() → FinishedParams: Generate the finished parameters to generate a full success FinishedPdu PDU.

class spacepackets.cfdp.FlowLabelTlv(flow_label: bytes)

Bases: AbstractTlvBase

TLV_TYPE = 5

classmethod from_tlv(cfdp_tlv: CfdpTlv) → FlowLabelTlv

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

classmethod unpack(data: bytes) → FlowLabelTlv

property value: bytes

exception spacepackets.cfdp.InvalidCrcError(crc16: int, message: str | None = None): Bases: Exception

class spacepackets.cfdp.LargeFileFlag(value)

Bases: IntEnum

An enumeration.

LARGE = 1

NORMAL = 0

class spacepackets.cfdp.MessageToUserTlv(msg: bytes)

Bases: AbstractTlvBase

Message to User TLV implementation as specified in CCSDS 727.0-B-5 5.4.3

TLV_TYPE = 2

classmethod from_tlv(cfdp_tlv: CfdpTlv) → MessageToUserTlv

is_reserved_cfdp_message() → bool

pack() → bytearray

property packet_len: int

property tlv_type: TlvType

to_reserved_msg_tlv() → ReservedCfdpMessage | None: Attempt to convert to a reserved CFDP message. Please note that this operation will fail if the message if not a reserved CFDP message and will then return None. This method is especially useful to have access to the more specialized ReservedCfdpMessage API.

classmethod unpack(data: bytes | bytearray) → MessageToUserTlv

property value: bytes

class spacepackets.cfdp.PduConfig(source_entity_id: UnsignedByteField, dest_entity_id: UnsignedByteField, transaction_seq_num: UnsignedByteField, trans_mode: TransmissionMode, file_flag: LargeFileFlag = LargeFileFlag.NORMAL, crc_flag: CrcFlag = CrcFlag.NO_CRC, direction: Direction = Direction.TOWARDS_RECEIVER, seg_ctrl: SegmentationControl = SegmentationControl.NO_RECORD_BOUNDARIES_PRESERVATION)

Bases: object

Common configuration fields for a PDU.

crc_flag: CrcFlag = 0

classmethod default() → PduConfig: Valid PDU configuration

dest_entity_id: UnsignedByteField

direction: Direction = 0

classmethod empty() → PduConfig: Empty PDU configuration which is not valid for usage because the contained unsigned byte fields are empty (sequence number and both entity IDs)

file_flag: LargeFileFlag = 0

header_len() → int

seg_ctrl: SegmentationControl = 0

source_entity_id: UnsignedByteField

trans_mode: TransmissionMode

transaction_seq_num: UnsignedByteField

class spacepackets.cfdp.PduFactory

Bases: object

Helper class to generate PDUs and retrieve PDU information from a raw bytestream

static from_raw(data: bytes | bytearray) → AbstractFileDirectiveBase | AbstractPduBase | None

static from_raw_to_holder(data: bytes | bytearray) → PduHolder

static is_file_directive(data: bytes | bytearray) → bool

static pdu_directive_type(data: bytes | bytearray) → DirectiveType | None

Retrieve the PDU directive type from a raw bytestream.

Raises:: ValueError – Invalid directive type.
Returns:: None, if the PDU in the given bytestream is not a file directive, otherwise the directive.

static pdu_type(data: bytes | bytearray) → PduType

class spacepackets.cfdp.PduHolder(pdu: AbstractFileDirectiveBase | AbstractPduBase | None)

Bases: object

Helper type to store arbitrary PDU types and cast them to a concrete PDU type conveniently

property base: AbstractFileDirectiveBase | AbstractPduBase | None: Deprecated since version 0.19.0: use packet member instead

property is_file_directive: bool

pack() → bytearray

property packet_len: int

property pdu_directive_type: DirectiveType | None: If the contained type is not a PDU file directive, returns None. Otherwise, returns the directive type

property pdu_type: PduType

to_ack_pdu() → AckPdu

to_eof_pdu() → EofPdu

to_file_data_pdu() → FileDataPdu

to_finished_pdu() → FinishedPdu

to_keep_alive_pdu() → KeepAlivePdu

to_metadata_pdu() → MetadataPdu

to_nak_pdu() → NakPdu

to_prompt_pdu() → PromptPdu

class spacepackets.cfdp.PduType(value)

Bases: IntEnum

An enumeration.

FILE_DATA = 1

FILE_DIRECTIVE = 0

class spacepackets.cfdp.SegmentMetadataFlag(value)

Bases: IntEnum

Aways 0 and ignored for File Directive PDUs (CCSDS 727.0-B-5 p.75)

NOT_PRESENT = 0

PRESENT = 1

class spacepackets.cfdp.SegmentationControl(value)

Bases: IntEnum

Always 0 and ignored for File Directive PDUs (CCSDS 727.0-B-5 p.75)

NO_RECORD_BOUNDARIES_PRESERVATION = 0

RECORD_BOUNDARIES_PRESERVATION = 1

class spacepackets.cfdp.TlvHolder(tlv: AbstractTlvBase | None)

Bases: object

property tlv_type: None | TlvType

to_entity_id() → EntityIdTlv

to_fault_handler_override() → FaultHandlerOverrideTlv

to_flow_label() → FlowLabelTlv

to_fs_request() → FileStoreRequestTlv

to_fs_response() → FileStoreResponseTlv

to_msg_to_user() → MessageToUserTlv

class spacepackets.cfdp.TlvType(value)

Bases: IntEnum

All available TLV types

ENTITY_ID = 6

FAULT_HANDLER = 4

FILESTORE_REQUEST = 0

FILESTORE_RESPONSE = 1

FLOW_LABEL = 5

MESSAGE_TO_USER = 2

exception spacepackets.cfdp.TlvTypeMissmatchError(found: TlvType, expected: TlvType): Bases: Exception

class spacepackets.cfdp.TransactionId(source_entity_id: UnsignedByteField, transaction_seq_num: UnsignedByteField): Bases: object

class spacepackets.cfdp.TransmissionMode(value)

Bases: IntEnum

An enumeration.

ACKNOWLEDGED = 0

UNACKNOWLEDGED = 1

PDU Submodule

CFDP PDU Subpackage

Configuration Submodule

class spacepackets.cfdp.conf.CfdpDict

Bases: TypedDict

source_dest_entity_ids: tuple[bytes, bytes]

class spacepackets.cfdp.conf.PduConfig(source_entity_id: UnsignedByteField, dest_entity_id: UnsignedByteField, transaction_seq_num: UnsignedByteField, trans_mode: TransmissionMode, file_flag: LargeFileFlag = LargeFileFlag.NORMAL, crc_flag: CrcFlag = CrcFlag.NO_CRC, direction: Direction = Direction.TOWARDS_RECEIVER, seg_ctrl: SegmentationControl = SegmentationControl.NO_RECORD_BOUNDARIES_PRESERVATION)

Bases: object

Common configuration fields for a PDU.

crc_flag: CrcFlag = 0

classmethod default() → PduConfig: Valid PDU configuration

dest_entity_id: UnsignedByteField

direction: Direction = 0

classmethod empty() → PduConfig: Empty PDU configuration which is not valid for usage because the contained unsigned byte fields are empty (sequence number and both entity IDs)