fix: return self when asked for self (#318)

Restores pre-1.x behaviour where when an RPC findNode request comes
in, if it's asking for us, return our info instead of looking for
closer peers which queries the routing table which may not have our
peer id in it.

src/rpc/handlers/find-node.ts

@@ -4,14 +4,14 @@ import {
   removePrivateAddresses,
   removePublicAddresses
 } from '../../utils.js'
-import { pipe } from 'it-pipe'
+import { equals as uint8ArrayEquals } from 'uint8arrays'
+import { Components } from '@libp2p/interfaces/components'
+import { protocols } from '@multiformats/multiaddr'
+import type { Initializable } from '@libp2p/interfaces/components'
+import type { PeerInfo } from '@libp2p/interfaces/peer-info'
 import type { DHTMessageHandler } from '../index.js'
 import type { PeerRouting } from '../../peer-routing/index.js'
 import type { PeerId } from '@libp2p/interfaces/peer-id'
-import map from 'it-map'
-import filter from 'it-filter'
-import all from 'it-all'
-import type { Initializable } from '@libp2p/interfaces/components'
 
 const log = logger('libp2p:kad-dht:rpc:handlers:find-node')
 
@@ -23,15 +23,16 @@ export interface FindNodeHandlerInit {
 export class FindNodeHandler implements DHTMessageHandler, Initializable {
   private readonly peerRouting: PeerRouting
   private readonly lan: boolean
+  private components = new Components()
 
   constructor (init: FindNodeHandlerInit) {
     const { peerRouting, lan } = init
     this.peerRouting = peerRouting
     this.lan = Boolean(lan)
   }
 
-  init (): void {
-
+  init (components: Components): void {
+    this.components = components
   }
 
   /**
@@ -40,14 +41,21 @@ export class FindNodeHandler implements DHTMessageHandler, Initializable {
   async handle (peerId: PeerId, msg: Message) {
     log('incoming request from %p for peers closer to %b', peerId, msg.key)
 
-    const mapper = this.lan ? removePublicAddresses : removePrivateAddresses
+    let closer: PeerInfo[] = []
+
+    if (uint8ArrayEquals(this.components.getPeerId().toBytes(), msg.key)) {
+      closer = [{
+        id: this.components.getPeerId(),
+        multiaddrs: this.components.getAddressManager().getAddresses().map(ma => ma.decapsulateCode(protocols('p2p').code)),
+        protocols: []
+      }]
+    } else {
+      closer = await this.peerRouting.getCloserPeersOffline(msg.key, peerId)
+    }
 
-    const closer = await pipe(
-      await this.peerRouting.getCloserPeersOffline(msg.key, peerId),
-      (source) => map(source, mapper),
-      (source) => filter(source, ({ multiaddrs }) => multiaddrs.length > 0),
-      async (source) => await all(source)
-    )
+    closer = closer
+      .map(this.lan ? removePublicAddresses : removePrivateAddresses)
+      .filter(({ multiaddrs }) => multiaddrs.length)
 
     const response = new Message(msg.type, new Uint8Array(0), msg.clusterLevel)
 

src/rpc/index.ts

@@ -16,7 +16,7 @@ import type { PeerRouting } from '../peer-routing'
 import type { Validators } from '@libp2p/interfaces/dht'
 import type { Components, Initializable } from '@libp2p/interfaces/components'
 
-export interface DHTMessageHandler {
+export interface DHTMessageHandler extends Initializable {
   handle: (peerId: PeerId, msg: Message) => Promise<Message | undefined>
 }
 
@@ -29,7 +29,7 @@ export interface RPCInit {
 }
 
 export class RPC implements Initializable {
-  private readonly handlers: Record<string, DHTMessageHandler & Initializable>
+  private readonly handlers: Record<string, DHTMessageHandler>
   private readonly routingTable: RoutingTable
   private readonly log: Logger
 

test/rpc/handlers/find-node.spec.ts

@@ -5,10 +5,14 @@ import { Message, MESSAGE_TYPE } from '../../../src/message/index.js'
 import { FindNodeHandler } from '../../../src/rpc/handlers/find-node.js'
 import { Multiaddr } from '@multiformats/multiaddr'
 import { createPeerId } from '../../utils/create-peer-id.js'
-import type { PeerId } from '@libp2p/interfaces/peer-id'
-import type { DHTMessageHandler } from '../../../src/rpc/index.js'
 import { PeerRouting } from '../../../src/peer-routing/index.js'
 import Sinon, { SinonStubbedInstance } from 'sinon'
+import { Components } from '@libp2p/interfaces/components'
+import type { PeerId } from '@libp2p/interfaces/peer-id'
+import type { DHTMessageHandler } from '../../../src/rpc/index.js'
+import type { AddressManager } from '@libp2p/interfaces'
+import { stubInterface } from 'ts-sinon'
+import type { StubbedInstance } from 'ts-sinon'
 
 const T = MESSAGE_TYPE.FIND_NODE
 
@@ -18,33 +22,33 @@ describe('rpc - handlers - FindNode', () => {
   let targetPeer: PeerId
   let handler: DHTMessageHandler
   let peerRouting: SinonStubbedInstance<PeerRouting>
+  let addressManager: StubbedInstance<AddressManager>
 
   beforeEach(async () => {
     peerId = await createPeerId()
     sourcePeer = await createPeerId()
     targetPeer = await createPeerId()
     peerRouting = Sinon.createStubInstance(PeerRouting)
+    addressManager = stubInterface<AddressManager>()
 
     handler = new FindNodeHandler({
       peerRouting,
       lan: false
     })
+    handler.init(new Components({
+      peerId,
+      addressManager
+    }))
   })
 
   it('returns self, if asked for self', async () => {
     const msg = new Message(T, peerId.multihash.bytes, 0)
 
-    peerRouting.getCloserPeersOffline
-      .withArgs(peerId.multihash.bytes, sourcePeer)
-      .resolves([{
-        id: peerId,
-        multiaddrs: [
-          new Multiaddr('/ip4/127.0.0.1/tcp/4002'),
-          new Multiaddr('/ip4/192.168.1.5/tcp/4002'),
-          new Multiaddr('/ip4/221.4.67.0/tcp/4002')
-        ],
-        protocols: []
-      }])
+    addressManager.getAddresses.returns([
+      new Multiaddr(`/ip4/127.0.0.1/tcp/4002/p2p/${peerId.toString()}`),
+      new Multiaddr(`/ip4/192.168.1.5/tcp/4002/p2p/${peerId.toString()}`),
+      new Multiaddr(`/ip4/221.4.67.0/tcp/4002/p2p/${peerId.toString()}`)
+    ])
 
     const response = await handler.handle(sourcePeer, msg)
 
@@ -115,6 +119,10 @@ describe('rpc - handlers - FindNode', () => {
       peerRouting,
       lan: true
     })
+    handler.init(new Components({
+      peerId,
+      addressManager
+    }))
 
     const response = await handler.handle(sourcePeer, msg)