bespokebpv7¶

Create, parse, and modify BPv7 (RFC 9171) bundles and LTP (RFC 5326) segments in Python.

Supports both RFC-compliant bundles and intentionally non-compliant bundles for V&V testing of DTN implementations.

Installation¶

pip install bespokebpv7

Quick Start¶

Happy Path — Create a Standard Bundle¶

import cbor2

from bespokebpv7 import BPv7, CRCType, parse_eid_string

# Build payload as CBOR (RFC 9171 encodes all data in CBOR)
payload = cbor2.dumps("Hello, World!")

# Initialize bundle and add payload block
bundle = BPv7()
bundle.add_payload_block(payload)

# Set creation timestamp, routing, and flags
bundle.primary_block.set_creation()
bundle.primary_block.route.source_eid = "ipn:2.1"
bundle.primary_block.route.dest_eid = "ipn:3.1"
bundle.primary_block.no_fragment = True
bundle.primary_block.crc_type = CRCType.CRC16

# Always re-compute CRC after modifying a block
bundle.primary_block.update_crc()

# Serialize
serialized: bytes = bytes(bundle)

V&V Path — Non-Compliant Bundle¶

from bespokebpv7 import BPv7, BundleFlags, CRCType

bundle = BPv7()
bundle.add_payload_block(b"test")

# Intentionally non-compliant: both IS_FRAGMENT and
# DO_NOT_FRAGMENT are set simultaneously.
bundle.primary_block.flags |= BundleFlags.IS_FRAGMENT
bundle.primary_block.flags |= BundleFlags.DO_NOT_FRAGMENT

bundle.primary_block.set_creation()
bundle.primary_block.route.source_eid = "ipn:2.1"
bundle.primary_block.route.dest_eid = "ipn:3.1"
bundle.primary_block.crc_type = CRCType.CRC16
bundle.primary_block.update_crc()

Parsing from Hex¶

import binascii
from bespokebpv7 import BPv7, BlockType

hex_bundle = (
    "9f88071844008202820301820100820100821b000000b5998c98"
    "2b011a000493e085060210004582028202008507040100421834"
    "85010101004454455354ff"
)
bundle = BPv7(binascii.unhexlify(hex_bundle))
print(bundle.primary_block.route.source_eid)
print(bundle.get_block_by_type(BlockType.PAYLOAD_BLOCK))

Documentation¶

API Reference — Detailed documentation for each module.
Guides — Conceptual and workflow guides.
Examples — Integration tests and usage patterns.

Dependencies¶

cbor2 — CBOR encoding/decoding
attrs — Class definition with validation
cattrs — Structure (de)serialization
dpkt — Packet manipulation base class
fastcrc — CRC calculations