Hardy

A performant, compliant, and extensible BPv7 DTN solution for the Cloud.

Overview

Hardy is a modular implementation of the Bundle Protocol Version 7 (BPv7) as defined in RFC 9171, designed for Delay-Tolerant Networking (DTN) applications. Written in reliable, accessible, asynchronous Rust, many components are rigorously tested using fuzzing to ensure robustness and security.

Table of Contents

• Hardy
  • Overview
  • Table of Contents
  • Features
  • Components
    • Core Libraries
    • Storage Engines
    • Convergence Layer Adapters
    • Services & Filters
    • Servers & Tools
  • Getting Started
    • Prerequisites
    • Building
    • Running the BPA Server
    • CLI Tools
  • Interoperability
  • Documentation
  • Contributing
  • License

Features

• Full RFC 9171 BPv7 bundle protocol support
• BPSec (RFC 9172/9173) for bundle security with HMAC-SHA and AES-GCM
• RFC 9174 TCPCLv4 convergence layer with TLS
• Pluggable storage backends (local filesystem, SQLite, PostgreSQL, S3)
• Time-Variant Routing with recurring schedule support
• Configurable ingress/egress filter pipeline
• gRPC API for application and CLA integration
• OpenTelemetry integration for observability (traces, metrics, logs)
• Interoperability verified against 7 independent BPv7 implementations
• no_std compatible core libraries for embedded use

Components

Core Libraries

Crate	Description
hardy-cbor	RFC 8949 compliant Canonical CBOR encoder/decoder with streaming API. no_std compatible.
hardy-bpv7	RFC 9171 BPv7 implementation with bundle creation, parsing, and manipulation. Includes BPSec support for integrity (BIB) and confidentiality (BCB) blocks. no_std compatible.
hardy-bpa	Complete Bundle Processing Agent library implementing DTN routing, dispatching, filter pipeline, RIB management, and CLA/service interfaces.
hardy-eid-patterns	EID pattern parsing and matching for IPN and DTN URI schemes with glob support.
hardy-async	Runtime-agnostic async primitives including TaskPool, sync wrappers (Mutex, RwLock, Once), and cancellation tokens.
hardy-proto	Protobuf v3 and gRPC API definitions for BPA-to-application and BPA-to-CLA communication.
hardy-otel	OpenTelemetry integration for distributed tracing, metrics, and structured logging.

Storage Engines

Crate	Description
hardy-sqlite-storage	SQLite-based metadata storage engine with automatic schema migration.
hardy-postgres-storage	PostgreSQL-based metadata storage engine.
hardy-localdisk-storage	Filesystem-based bundle storage with configurable fsync and recovery support.
hardy-s3-storage	S3-compatible object storage for bundle data, supporting AWS S3 and MinIO.

Convergence Layer Adapters

Crate	Description
hardy-tcpclv4	RFC 9174 TCPCLv4 implementation with TLS support, session management, and structured logging.
hardy-file-cla	File-system-based CLA for bundle exchange via watched directories.
hardy-bibe	Bundle-in-Bundle Encapsulation (BIBE) for tunneling bundles through intermediate networks.

Services & Filters

Crate	Description
hardy-echo-service	Echo service for testing and diagnostics - reflects bundles back to sender.
hardy-ipn-legacy-filter	Egress filter for legacy 2-element IPN EID encoding compatibility.

Servers & Tools

Crate	Description
hardy-bpa-server	Modular BPv7 Bundle Processing Agent server with gRPC API, multiple storage backends, configurable filters, and static routing.
hardy-tcpclv4-server	Standalone TCPCLv4 listener and session handler.
hardy-bpv7-tools	CLI (bundle) for bundle operations: create, inspect, validate, sign, encrypt, and more.
hardy-cbor-tools	CLI (cbor) for CBOR inspection and conversion between binary, CDN, and JSON formats.
hardy-tvr	Time-Variant Routing agent — installs and withdraws routes based on contact schedules (cron, file, gRPC).
hardy-tools	General DTN utilities including the bp command for ping and bundle operations.

Getting Started

Prerequisites

• Rust 2024 edition (1.87+)
• Cargo

Building

# Build all packages
cargo build --release

# Build the BPA server with all features
cargo build --release -p hardy-bpa-server --all-features

# Run tests
cargo test --workspace

Running the BPA Server

From source:

./target/release/hardy-bpa-server -c bpa-server/config.yaml

Via Docker Compose (with PostgreSQL + MinIO):

docker compose up --build -d

For a lightweight setup with in-memory storage (no PostgreSQL/MinIO):

docker compose --profile debug up --build hardy-debug

The server listens on gRPC (50051) and TCPCLv4 (4556). Configuration is in bpa-server/config.yaml; edit it to change node settings. See the bpa-server README for all options.

To send a test ping to the echo service:

bp ping ipn:1.7 127.0.0.1:4556

CLI Tools

Three command-line tools are available, also bundled in the ghcr.io/ricktaylor/hardy/hardy-tools:latest Docker image:

Tool	Package	Description
bp	hardy-tools	Network diagnostics — bp ping measures RTT, packet loss, and path visibility.
bundle	hardy-bpv7-tools	Bundle operations — create, inspect, validate, sign, encrypt, and more.
cbor	hardy-cbor-tools	CBOR inspection and conversion between binary, CDN, and JSON.

From source:

# Ping a remote node
bp ping ipn:2.7 192.168.1.1:4556

# Inspect a bundle
bundle inspect bundle.cbor

# Create, sign, and inspect a bundle
echo "Hello DTN" | bundle create -s ipn:1.0 -d ipn:2.0 - \
  | bundle sign -k key.jwk - \
  | bundle inspect -

# Inspect CBOR data
cbor inspect data.cbor

Via Docker:

docker run --rm --network host ghcr.io/ricktaylor/hardy/hardy-tools:latest \
  bp ping ipn:2.7 192.168.1.1:4556

See the bp-ping man page, bpv7-tools README, and cbor-tools README for full documentation.

Interoperability

Hardy is tested for bidirectional bundle exchange against multiple BPv7 implementations:

Implementation	CLA	Source
Hardy (self-test)	TCPCLv4	-
dtn7-rs	TCPCLv4	GitHub
NASA HDTN	TCPCLv4	GitHub
NASA DTNME	TCPCLv4	GitHub
JPL ION	STCP	GitHub
ud3tn	MTCP	GitLab
ESA BP	STCP	ESA ESSR
NASA cFS BPNode	STCP	GitHub

Each test verifies ping/echo in both directions. A benchmark script compares RTT across all implementations.

# Run all interop tests with RTT comparison
./tests/interop/run_all.sh

# Run a single implementation test
./tests/interop/HDTN/test_hdtn_ping.sh

See tests/interop/README.md for details.

Documentation

Document	Description
User Guide	Getting started, configuration reference, and deployment guide.
Architecture Overview	High-level system architecture and design principles.
Requirements	High-level and low-level requirements with RFC traceability.
Test Strategy	Overall testing approach including unit, integration, and fuzz testing.
Test Coverage	Project-wide test plan inventory and coverage metrics.
Requirements Coverage	Requirements traceability matrix and LLR verification status.
Interop Tests	Interoperability test suite for 7 BPv7 implementations.

Contributing

We welcome contributions to the Hardy project! If you would like to contribute, please follow these guidelines:

1. Fork the repository and create a new branch for your contribution.
2. Make your changes and ensure the code follows the coding style guide and passes the CI checks (cargo fmt --check and cargo clippy --all-targets --all-features -- -D warnings).
3. Write tests to cover your changes and ensure that all existing tests pass.
4. Submit a pull request with a clear description of your changes and the problem they solve.

Before contributing, please familiarize yourself with the coding style guide and the project's Test Strategy to understand our conventions and approach to quality. AGENTS.md summarises the build, test, and style essentials in one place — it is also the file that AI coding assistants load.

By contributing to Hardy, you agree to license your contributions under the project's license.

License

Hardy is licensed under the Apache 2.0 License.