ndn-embeds

Lightweight Named Data Networking (NDN) protocol stack for embedded systems, designed as an ESP-IDF component.

Real-time camera streaming over NDN with ESP-NOW

Features

• Full NDN packet encoding/decoding — Interest, Data, Name with TLV wire format (NDN Packet Format Specification v0.3)
• Forwarding engine — Forwarder with PIT, CS (Content Store with LRU eviction), and FIB (longest-prefix match)
• ESP-NOW Face — Zero-configuration peer-to-peer communication over ESP-NOW
• ECDSA P-256 signatures — Data signing and verification using mbedTLS
• X.509 certificate support — NDN Certificate v2 format encoding/decoding
• Link object support — Forwarding hints for multi-hop routing
• No dynamic allocation — All data structures use fixed-size arrays; no new/delete
• No exceptions — Error handling via Result<T> return types
• C++23 — Modern C++ with std::optional, std::array, std::string_view
• 214 unit tests — Comprehensive test coverage with ESP-IDF Unity framework

Requirements

• ESP-IDF v5.0 or later
• Target: ESP32, ESP32-S3, ESP32-C3, or ESP32-C6

Installation

As an ESP-IDF component (recommended)

cd your_project
mkdir -p components
cd components
git clone https://github.com/sou1118/ndn-embeds.git ndn

Via ESP Component Registry

idf.py add-dependency "sou1118/ndn-embeds"

Quick Start

Consumer

#include <ndn/ndn.hpp>

extern "C" void app_main() {
    ndn::initialize();

    auto& fwd = ndn::getForwarder();
    ndn::EspNowFace face;
    face.start();
    fwd.addFace(&face);

    ndn::Interest interest;
    interest.setName("/sensor/temperature")
            .setLifetime(4000)
            .generateNonce();

    fwd.expressInterest(interest,
        [](const ndn::Data& data) {
            printf("Received: %.*s\n",
                   (int)data.contentSize(),
                   (const char*)data.content());
        },
        [](const ndn::Interest&) {
            printf("Timeout\n");
        }
    );

    while (true) {
        face.processReceiveQueue();
        fwd.processEvents();
        vTaskDelay(pdMS_TO_TICKS(10));
    }
}

Producer

#include <ndn/ndn.hpp>

extern "C" void app_main() {
    ndn::initialize();

    auto& fwd = ndn::getForwarder();
    ndn::EspNowFace face;
    face.start();
    fwd.addFace(&face);

    fwd.registerPrefix("/sensor/temperature",
        [](const ndn::Interest& interest, ndn::FaceId) {
            ndn::Data data;
            data.setName(interest.name());
            data.setContent("25.5");
            data.setFreshnessPeriod(5000);
            ndn::putData(data);
        }
    );

    while (true) {
        face.processReceiveQueue();
        fwd.processEvents();
        vTaskDelay(pdMS_TO_TICKS(10));
    }
}

Architecture

block-beta
    columns 1

    block:app
        A["Application Layer"]
    end

    block:api
        B["NDN API Layer\nexpressInterest() / registerPrefix()"]
    end

    block:core
        columns 4
        C["TLV\nEncoder"]
        D["PIT\nManager"]
        E["CS\nManager"]
        F["FIB\nManager"]
    end

    block:fwd
        G["Forwarder"]
    end

    block:face
        H["Face (Base)"]
        I["EspNowFace"]
    end

    block:transport
        J["ESP-NOW API"]
    end

    block:hw
        K["Wi-Fi Driver"]
    end

    app --> api
    api --> core
    core --> fwd
    fwd --> face
    face --> transport
    transport --> hw

Loading

API Overview

Module	Header	Description
Common	ndn/common.hpp	Error codes, Result<T>, constants
TLV	ndn/tlv.hpp	TLV encoder/decoder
Name	ndn/name.hpp	NDN Name with component operations
Interest	ndn/interest.hpp	Interest packet (Nonce, Lifetime, HopLimit)
Data	ndn/data.hpp	Data packet (Content, FreshnessPeriod)
Signature	ndn/signature.hpp	SignatureInfo/SignatureValue
Crypto	ndn/crypto.hpp	ECDSA P-256 signing/verification
Certificate	ndn/certificate.hpp	NDN Certificate v2
Link	ndn/link.hpp	Link object with delegation list
PIT	ndn/pit.hpp	Pending Interest Table
CS	ndn/cs.hpp	Content Store (LRU)
FIB	ndn/fib.hpp	Forwarding Information Base
Face	ndn/face.hpp	Abstract face interface
Forwarder	ndn/forwarder.hpp	NDN forwarder
EspNowFace	adapters/espnow_face.hpp	ESP-NOW transport

Constraints

Resource	Limit
ESP-NOW max payload	250 bytes
Name max length	128 bytes
Name max components	10
Data max content size	200 bytes
PIT entries	50
CS entries	20
FIB entries	30
Interest default lifetime	4000 ms

Documentation

API documentation is available at https://sou1118.github.io/ndn-embeds/

Generated automatically from source comments using Doxygen on each push to main.

Running Tests

cd test_app
idf.py set-target esp32s3
idf.py build
idf.py -p /dev/ttyUSB0 flash monitor

License

Apache License 2.0. See LICENSE for details.