ud3tn/CHANGELOG.md

µD3TN Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[v0.15.0] - 2026-05-19

Deprecated

• AAPv1 will be removed in the future -- please use AAP 2.0

Added

• Support for RFC 9758: implement the ipn 3-element format and LocalNode (ipn:!.x) EIDs
• Custom source EIDs (including dtn:none) can be specified via AAP 2.0 and the corresponding tools (e.g. aap2-send --source <eid>), as long as the client provides the administrative (BDM) secret and requests BDM authorization
• Add a compile-time flag CLA_MTCP_ION_STCP_COMPATIBILITY to make the MTCP CLA compatible with ION's STCP, which uses a different encoding for the length field. Note that this breaks compatibility with other implementations of the current MTCP draft specification.
• Add a compile-time flag BUNDLE7_ALLOW_NO_PRIMARY_CRC_NO_BIB (on by default) to allow processing bundles without a primary block CRC and no BIB.
• Add a small Python tool (aap2-fib-logger) to show FIB changes propagated via AAP 2.0 (also as an example how to handle this)

Removed

• The --agentid option has been removed for aap2-bdm-static and aap2-configure-link, which do not need to register an agent ID, as they do not send/receive bundles.

Changed

• We now enforce more properties concerning the RFC conformance of incoming bundles.
• We now check the file length for bundles passed to the data decoder.
• Many cleanups around EIDs: they are now represented internally as a data structure, making their handling more efficient
• Many cleanups and some fixes around reports, dropping BPv6 custody signaling, which we did not support anyways

Fixed

• AAP 2.0 agents can now be registered without an agent ID in case they do not wish to send/receive bundles (e.g. if they only do FIB control).
• The full FIB is now only sent once to AAP 2.0 FIB subscribers, when they connect. Then, only changes are propagated.

v0.14.5 - 2025-09-26

Added

• Implement a tool to inject bundles via MTCP (tools/cla/mtcp_send_bundle.py)
• Enable the creation of BPv7 "Previous Node" extension blocks when the compile time option BUNDLE7_TX_PRODUCE_PREVIOUS_NODE_BLOCK is set to 1 (disabled by default).

Changed

• Change the default administrative record type code for BIBE to 64443 (as per the newest draft), and allow for changing it using the BIBE_AR_TYPE_CODE compile-time option. This replaces the BIBE_CL_DRAFT_1_COMPATIBILITY option, which was setting the type code to 7 to enable ION interoperability.
• Update the pinned nixpkgs version from 25.05 to 25.11
• The default application of the nix run command has been removed. To run μD3TN as usual, the application name must be specified: nix run ‘?.submodules=1#ud3tn’

v0.14.4 - 2025-08-22

Fixed

• Fix a crash in TCPCLv3 when an incoming connection replaces and stops a link task that is performing outgoing connection attempts (#256, !231)
• Fix an issue in the contact-based scheduling and forwarding (DFCF) logic dropping bundles received during a contact, which already had one link associated with it that terminated/dropped before the contact ended, and is now trying to reconnect (#258, !233)

Changed

• All client-related headers for AAP 2.0 plus all Python libraries and tools are now available under the Apache 2.0 and BSD 3-clause licenses instead of AGPL v3. This ensures that there are no issues with commercial AAP 2.0 clients or derivatives.

v0.14.3 - 2025-07-25

Security

• Fix possible DoS: Fix a NULL pointer dereference if a bundle's destination EID is a non-singleton EID (#255)

Added

• Implement a new JSON-based contact configuration format and use it in the CLI tools (whereas the CLI tool parameters remain unchanged)
• Implement support for requesting and receiving status reports to AAP2 and the respective tools
• Add Protobuf APIs (AAP2, Storage Agent) to the web documentation
• Document Contact and Link configuration concepts, interfaces, and tools

Changed

• Enhance the validation of incoming bundles, checking their BP conformance before further processing
• Perform basic EID validations also in the Python tooling to provide better error messages in case of issues
• Update dependencies

v0.14.2 - 2024-12-04

Security

• Fix a potential double-free vulnerability (#233, may lead to DoS under Glibc)

Added

• Update and significantly extend µD3TN's documentation, use mkDocs for rendering it and publish it on https://d3tn.gitlab.io/ud3tn/

Changed

• Adapt the default TCP port for AAP 2.0 from 4242 to 4244 so it does not conflict with AAP

v0.14.1 - 2024-10-28

Added

• Enable AAP 2.0 to use a TCP socket instead of only a POSIX IPC socket

Fixed

• Fix a reachable assertion in the BPv7 parser (#227)

v0.14.0 - 2024-10-01 - "Nivium"

Added

This release contains two major new features, which should be considered experimental:

1. A modular forwarding and routing interface leveraging AAP 2.0:
   • AAP 2.0 is extended to allow applications to a) control and monitor outgoing links and b) perform forwarding decisions.
   • A shared-secret authentication + authorization procedure is implemented — applications intending to perform privileged actions need to specify an "administrative secret" passed to µD3TN at launch through an environment variable.
   • Moreover, two Python implementations of forwarding algorithms (Bundle Dispatch Modules, BDMs) are provided: a "compatibility BDM" implementing the well-known µD3TN forwarding approach and a simple static BDM based on a JSON routing table, intended to be used as a template for developing further BDMs.
2. A persistent storage feature based on SQLite, implemented as a CLA that represents a "storage-only bundle node" conceptionally:
   • This makes persistent storage a "next hop" to which bundles can be sent based on the decision of the used forwarding algorithm.
   • Releasing and/or dropping bundles from storage is controlled through a Protobuf-based API provided by the storage system on a dedicated endpoint.
   • Authorization is ensured via a flag set through AAP 2.0 if the administrative secret has been specified.

Additionally, the following new features are contained in this release:

• Extended and new tooling for controlling µD3TN through AAP 2.0.
• Extend the provided Nix tooling and integration.
• Allow FIB entries to specify a "direct dispatch" flag that causes the BPA to not consult the BDM, but directly forward bundles if their destination matches.

Changed

• License change: µD3TN as a whole is now provided unter the terms of the GNU AGPL. Some parts (e.g. the Python tools and some modules) will stay under the terms of the Apache 2 and BSD licenses.
• Graceful Termination of CLAs and the AAP 2.0 agent.
• Restructuring of the integrated next-hop forwarding approach so it is much more modular and can be fully disabled when using an external forwarding daemon (BDM).
• Move the Python tools to the python-ud3tn-utils package (links are provided in Git for backward-compatibility).
• Usability improvements for the AAP and AAP 2.0 interfaces.
• Reliability and consistency improvements as well as general cleanups, bug fixes, and documentation improvements.

Deprecated

• The aap_config.py utility has been deprecated in favor of aap2-config, as it cannot set the flag required for secure operation. To continue using it, µD3TN needs to be launched with the --allow-remote-config commandline argument.

v0.13.0 - 2023-12-22 - "Maxwell"

Added

• Preview version of AAP 2.0 - a new Protobuf-based application interface, with Python tooling equivalent to the AAP 1.0 tools provided in tools/aap2; see doc/aap20.md
• Added a "data decoder" that can be built using make data-decoder and allows for inspecting captured bundles and CLA packets as well as running fuzz testing on the parsers
• Support for local node IDs not containing a terminating slash (dtn scheme) or a service number (ipn scheme)
• Introduce configurable log levels - you can now select how verbose the output should be and debug log messages are disabled at compile time for more performant release builds
• Added a Nix Flake definition and a Nix-based development environment
• Automated testing on macOS and FreeBSD

Changed

• Moved all compile-time configuration options to config.mk with examples and defaults documented in config.mk.example
• Improved rate limiting for outgoing CLA connections that now also works when operating over SSH tunnels
• Improved interoperability testing, including tests against HDTN and DTN7-rs
• Improved static analysis, including automated execution of cppcheck
• Pinning of Python dependencies to ensure a deterministic Python environment
• Several small bug fixes, more tests, and general improvements

v0.12.0 - 2023-05-23 - "Loki"

Added

• macOS support
• FreeBSD support
• ARM and ARM-64 support with Clang and GCC compilers
• aap_echo and aap_ping utilities plus a built-in echo agent to realize basic reachability and latency tests
• transparent delivery of the bundle creation timestamp to applications via the AAP bundle identifier
• CBHE (RFC 6260) support for incoming BPv6 bundles

Changed

• improved interoperability testing with ION 3.7 and 4.1 plus IONe and added documentation for it
• substantial improvements of the test toolchain, including a Docker image with all dependencies, static analysis, and support for sanitizers
• improved IPv6 support
• lots of further bug fixes and improvements, internal simplifications, and cleanups

Removed

• removal of the unused STM32 target

v0.11.0 - 2022-03-08 - "Kerwan"

Added

• Implement Bundle-in-Bundle Encapsulation convergence layer (in this initial version without custody transfer features)
• Add proper support for the ipn: EID scheme (BPv7 and BPv6 without CBHE)
• Enable contacts with "infinite" capacity (long-running, high-data-rate contacts where the capacity does not matter anymore are considered to allow for infinite bundles)
• Add a simple bundle forwarding stress test

Changed

• Make the remote configuration capability a command line flag
• Update license: µD3TN is now additionally provided under the Apache 2.0 license

Fixed

• Fix build of libud3tn.so shared library
• Fix EID validation being too permissive

v0.10.0 - 2021-09-24 - "Juliet"

Added

• BPv7 compatibility:
  • Millisecond-based timestamps
  • Support of Bundle Age extension block
  • Drop previous node block (unsupported by µD3TN, but has to be removed according to standard)
• Add a Docker image
• Make it possible to use an RX read timeout for unreliable connections

Changed

• Disallow remote configuration: Config bundles are only accepted via AAP
• Use working directory instead of /tmp for AAP socket by default
• Increase maximum number of fragments
• Bugfixes and documentation improvements (e.g., README, quick start guide)

v0.9.0 - 2020-11-19 - "Imbrium"

This is the initial public release of µD3TN. This section documents the changes between µPCN v0.8.0 and this release.

Changed

• GitLab publication and renaming to µD3TN
• Public Continuous Integration pipeline
• Separation of Python modules into packages pyD3TN and ud3tn-utils
• Minor bugfixes and documentation improvements

µPCN v0.8.0 - 2020-10-31 - "Himalayas"

Added

• Support for BPv7 draft version 22
• ION interopability test for BPv7

Changed

• Updated license information
• Updated command line parser
• Replaced TCP socket used for AAP by a UNIX domain socket
• Updated documentation

µPCN v0.7.0 - 2019-11-06 - "Galaxius"

Added

• MTCP implementation according to https://tools.ietf.org/html/draft-ietf-dtn-mtcpcl-00
• CLA parameters plus parts of the µPCN configration can be provided as CLI parameters
• Added support for BPv7 draft version 17 (https://tools.ietf.org/html/draft-ietf-dtn-bpbis-17)
• IPv6 support for CLAs
• Support for a DTN application API based on an Application Agent Protocol (AAP)
• ION interopability test

Changed

• Modified the overall architecture of the communication subsystem
• Major refactoring of build system
• New packet format of STM32 USB CLA made compatible with MTCP
• Replacement of integration tests by new pyupcn-based toolchain

Removed

• Removed neighbor discovery approach

µPCN v0.6.0 - 2018-05-01 - "Falsaron"

In this release, an updated version of the Bundle Protocol version 7 draft specification (draft version 10) is available. Furthermore, the transmission and receive subsystem has been restructured to support various convergence layers.

Added

• Integration of the TCPCL convergence layer
• Support for the Space Packet Protocol (SPP)

Changed

• Update of the BP-bis implementation to RFC draft version 10 (https://tools.ietf.org/html/draft-ietf-dtn-bpbis-10)
• Partial project restructuring
• Various bugfixes

µPCN v0.5.0 - 2017-05-20 - "Elysium"

The main goal of this release was to include support for the Bundle protocol version 7 draft specification for testing and evaluation purposes.

Added

• Implementation of the BP-bis draft specification defined by https://tools.ietf.org/html/draft-ietf-dtn-bpbis-06
• Support for FreeRTOS 9

Changed

• Fixing various bugs after running fuzzing tests

µPCN v0.4.0 - 2016-12-02 - "Denali"

The main goal of this release was to port µPCN to the POSIX interface.

Added

• Add POSIX support

Changed

• Restructured µPCN to make it work against a generic, platform independent interface
• Improved Bundle serialization / throughput
• Extended test tools
• Several bug fixes

µPCN v0.3.1 - 2016-09-16

Fixed

• The serializer erroneously emits the data body length field before the eid fields. This was a violation of the block RFC 5050 block layout.

µPCN v0.3.0 - 2016-06-24 - "Caloris"

The main goal of this release was to integrate a contact prediction approach.

Added

• Integrated new version of the Ring Road Neighbor Discovery (RRND)
• Implemented enhanced contact prediction approach based on RRND and SGP4
• Provided static code analysis (make clang-check)

Changed

• Restructured GroundStationTask - one Task cares for several ground stations
• Extended test tools
• Several bug fixes plus performance improvements

µPCN v0.2.0 - 2015-11-15 - "Boösaule"

This release focused on stabilizing the initial release.

Added

• Added trust handling to the ContactManager
• Extended test infrastructure (e.g. Denial-of-Service test is available)
• Implemented zero-copy-approach by using a pointer lookup table for often used data (e.g. EIDs)
• Increased configurability of µPCN
• Improved error handling

Changed

• Bugfixing, restructuring and cleanup

µPCN v0.1.0 - 2015-03-29 - "Aeolis"

This was the initial release of µPCN.

Added

• RFC 5050 conformant bundle protocol version 6 implementation
• Two-stage routing approach with decision optimization between contacts
• DTN IP Neighbor Discovery (IPND draft 02) with extensions for RX/TX bitrate, AX.25 CLA address and cookie to protect against DoS attacks
• Unit test suite and integrated debugging tools (mem management, logging, CPU)
• Test setup for running pre-defined test scenarios with TCP server