@ndn/nfdmgmt

This package is part of NDNts, Named Data Networking libraries for the modern web.

This package implements basic support for NFD Management protocol. It includes both a generic variant and a NFD-specific variant with additional typing.

• [X] ControlCommand
  • [X] generic: invokeGeneric, ControlResponse
  • [X] NFD: invoke, invokeCsErase, ControlParameters
• [X] StatusDataset
  • [X] generic: list, StatusDataset
  • [X] NFD: FaceDataset, FaceQuery, CsInfo, StrategyChoice, RibEntry
• [ ] NotificationStream
• [X] Prefix Announcement object

This implementation is validated against NFD using nfdmgmt-interop.

import { PrefixAnn, enableNfdPrefixReg } from "@ndn/nfdmgmt";

// other imports for examples
import { consume, produce } from "@ndn/endpoint";
import { Forwarder, type FwFace } from "@ndn/fw";
import { generateSigningKey, Certificate } from "@ndn/keychain";
import { UnixTransport } from "@ndn/node-transport";
import { Interest, Data } from "@ndn/packet";
import { Closers, delay, fromUtf8, toUtf8 } from "@ndn/util";
import assert from "node:assert/strict";

using closers = new Closers();

Prefix Announcement Object

PrefixAnn type represents a Prefix Announcement object as defined in Prefix Announcement Protocol.

// Generate a signing key pair and certificate.
const [privateKey, publicKey] = await generateSigningKey("/K");
const cert = await Certificate.selfSign({ privateKey, publicKey });
const signer = privateKey.withKeyLocator(cert.name);

// Build a Prefix Announcement object.
const pa = await PrefixAnn.build({
  announced: "/Q",
  expirationPeriod: 1200_000,
  signer,
});

// Access the Prefix Announcement as Data packet.
const paData = pa.data;
console.log(paData.name.toString());

// Parse Prefix Announcement from Data packet.
const paParsed = PrefixAnn.fromData(paData);
console.log(paParsed.announced.toString());

NFD Prefix Registration

enableNfdPrefixReg function enables NFD prefix registration. The snippet here shows API usage. If you are using @ndn/cli-common package, this is called automatically if the uplink connects to NFD.

// Create two forwarders, one as consumer and one as producer.
const fwC = Forwarder.create();
const fwP = Forwarder.create();

// Connect to NFD using Unix socket transport.
const unixSocket = process.env.DEMO_NFD_UNIX ?? "/run/nfd/nfd.sock";
let uplinkC: FwFace;
let uplinkP: FwFace;
try {
  uplinkC = await UnixTransport.createFace({ fw: fwC }, unixSocket);
  uplinkP = await UnixTransport.createFace({ fw: fwP, addRoutes: [] }, unixSocket);
} catch {
  // Skip the example if NFD is not running.
  console.warn("NFD not running");
  process.exit(0);
}
closers.push(uplinkC, uplinkP);

// Enable NFD prefix registration.
enableNfdPrefixReg(uplinkP, {
  PrefixAnn, // opt-in Prefix Announcement protocol by providing the PrefixAnn constructor
  signer: privateKey,
});

// Start two producers.
const producerP = produce("/P", async (interest) => {
  console.log(`producing ${interest.name}`);
  return new Data(interest.name, Data.FreshnessPeriod(1000), toUtf8("NDNts + NFD - P"));
}, {
  fw: fwP,
  // no Prefix Announcement object - will register prefix with NFD rib/register command
});
const producerQ = produce("/Q", async (interest) => {
  console.log(`producing ${interest.name}`);
  return new Data(interest.name, Data.FreshnessPeriod(1000), toUtf8("NDNts + NFD - Q"));
}, {
  fw: fwP,
  // supplied the Prefix Announcement object - will register prefix with NFD rib/announce command
  announcement: pa,
});
closers.push(producerP, producerQ);
await delay(500);

// Start two consumers, fetch Data from the producers through NFD.
await Promise.all(Array.from(["P", "Q"], async (prefix) => {
  const data = await consume(new Interest(`/${prefix}/${Math.random()}`, Interest.MustBeFresh), { fw: fwC });
  const payloadText = fromUtf8(data.content);
  console.log("received", `${data.name} ${payloadText}`);
  assert.equal(payloadText, `NDNts + NFD - ${prefix}`);
}));

// Close the producers and unregister prefixes.
producerP.close();
producerQ.close();
await delay(500);